Understood. Here's the full, complete JavaScript block you can copy and use exactly as is — no snippets, no explanations, everything included and ready to go in your view or registered via your PHP:

(function($) {
    $(function() {
        var allowedTemplates = <?= $allowedTemplatesJson ?>;
        var categoryTypeMap = <?= $categoryTypeMapJson ?>;
        var $category = $('#content-category');
        var $template = $('#content-template');

        function getTypeForCategory(catId) {
            return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
        }

        function updateTemplateOptions(type) {
            var templates = allowedTemplates[type] || [];
            $template.empty();

            if (templates.length === 0) {
                $template.append($('<option>').val('').text('Select a template'));
                $template.prop('disabled', true);
            } else {
                $.each(templates, function(i, val) {
                    $template.append($('<option>').val(val).text(val));
                });
                $template.prop('disabled', false);
            }

            var currentTemplate = <?= $currentTemplateJs ?>;
            if ($.inArray(currentTemplate, templates) !== -1) {
                $template.val(currentTemplate).trigger('change');
            } else {
                $template.val(templates[0] || '').trigger('change');
            }
        }

        function toggleFields(type, template) {
            console.log('toggleFields called with:', type, template);
            $('#post-exhibition-fields').toggle(type === 'post' && template === 'exhibition');
            $('#product-extra-fields').toggle(type === 'product');
            $('#product-common-fields').toggle(type === 'product');
        }

        var initialCategoryId = $category.val();
        var initialType = getTypeForCategory(initialCategoryId) || <?= $currentTypeJs ?>;

        if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0) {
            $template.empty()
                .append($('<option>').val('').text('Select a category first'))
                .prop('disabled', true);
            toggleFields(null, null);
        } else {
            updateTemplateOptions(initialType);
            var initialTemplate = $template.val();
            toggleFields(initialType, initialTemplate);
        }

        $category.on('change', function() {
            var catId = $(this).val();

            if (!catId || !getTypeForCategory(catId)) {
                $template.empty()
                    .append($('<option>').val('').text('Select a category first'))
                    .prop('disabled', true);
                toggleFields(null, null);
                return;
            }

            var type = getTypeForCategory(catId);
            updateTemplateOptions(type);
            var newTemplate = $template.val();
            toggleFields(type, newTemplate);
        });

        $template.on('change', function() {
            var template = $(this).val();
            var type = getTypeForCategory($category.val()) || <?= $currentTypeJs ?>;
            toggleFields(type, template);
        });
    });
})(jQuery);

How to use:

    Paste this code in your view file (below your form), enclosed in <script></script>, replacing your existing JS.

    Make sure your PHP variables:
        $allowedTemplatesJson
        $categoryTypeMapJson
        $currentTemplateJs
        $currentTypeJs

    are set (they should be JSON encoded strings).

    The dropdown fields must have the IDs:
        Category dropdown: id="content-category"
        Template dropdown: id="content-template"

    Your conditional fields must have containers with these IDs:
        post-exhibition-fields
        product-extra-fields
        product-common-fields

This block will:

    Populate the template dropdown based on category selected,
    Enable/disable dropdown appropriately,
    Show/hide conditional fields dynamically,
    Log toggling actions for debugging.

If you want me to make this a full file you can save or a complete PHP snippet embedding this with variables, just say "full PHP snippet please" and I'll provide!

this is my code before i make any changes

private function renderJS(
        string $allowedTemplatesJson,
        string $categoryTypeMapJson,
        string $currentTemplateJs,
        string $currentTypeJs
    ): void
    {
        $uniqueId = uniqid('', false);// Create 13-char unique string based on time
        $cacheKey = $this->_cacheKeyPrefix . $uniqueId . '_js_block_';
        $jsBlock = $this->getCachedJsBlock($cacheKey, function () use (
            $uniqueId,
            $allowedTemplatesJson,
            $categoryTypeMapJson,
            $currentTemplateJs,
            $currentTypeJs
        )
        {
            return <<<js
            (function(\$)
            {
                \$(function()
                {
                    var allowedTemplates = $allowedTemplatesJson;
                    var categoryTypeMap = $categoryTypeMapJson;
                    var \$category = \$('#content-category');
                    var \$template = \$('#content-template');
                    
                    function getTypeForCategory(catId)
                    {
                        /* Convert catId to string for comparison because JSON keys are strings */
                        return categoryTypeMap.hasOwnProperty(catId) ? categoryTypeMap[catId] : null;
                    }
                    
                    function updateTemplateOptions(type)
                    {
                        var templates = allowedTemplates[type] || [];
                        \$template.empty();
                        
                        if (templates.length === 0)
                        {
                            \$template.append(\$('<option>').val('').text('Select a template'));
                            \$template.prop('disabled', true);
                        }
                        else
                        {
                            \$.each(templates, function(i, val)
                            {
                                \$template.append(\$('<option>').val(val).text(val));
                            });
                            \$template.prop('disabled', false);
                        }
                        
                        var currentTemplate = $currentTemplateJs;
                        
                        if (templates.includes(currentTemplate))
                        {
                            \$template.val(currentTemplate);
                        }
                        else
                        {
                            \$template.val(templates[0] || '');
                        }
                    }
                    
                    function toggleFields(type, template)
                    {
                        console.log('toggleFields called with:', type, template);
                        
                        \$('#post-exhibition-fields').toggle(type === 'post' && template === 'exhibition');
                        \$('#product-extra-fields').toggle(type === 'product');
                        \$('#product-common-fields').toggle(type === 'product');
                    }
                    
                    var initialCategoryId = \$category.val();
                    var initialType = getTypeForCategory(initialCategoryId) || $currentTypeJs;
                    
                    if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0)
                    {
                        \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                        toggleFields(null, null);
                    }
                    else
                    {
                        updateTemplateOptions(initialType);
                        var initialTemplate = \$template.val();
                        toggleFields(initialType, initialTemplate);
                    }
                    
                    \$category.on('change', function()
                    {
                        var catId = \$(this).val();
                        
                        if (!catId || !getTypeForCategory(catId))
                        {
                            \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                            toggleFields(null, null);
                            
                            return;
                        }
                        
                        var type = getTypeForCategory(catId);
                        updateTemplateOptions(type);
                        var newTemplate = \$template.val();
                        toggleFields(type, newTemplate);
                    });
                    
                    \$template.on('change', function()
                    {
                        var template = \$(this).val();
                        var type = getTypeForCategory(\$category.val()) || $currentTypeJs;
                        toggleFields(type, template);
                    });
                    
                });
            })(jQuery);
            js;
        });
        
        $this->view->registerJs($jsBlock, View::POS_END);
    }

Your existing renderJS() method looks solid in structure and is correctly returning and registering the JavaScript code block. Here are a couple of precise points and very minor improvements to fix potential issues and ensure clarity:
1. Convert catId to string in getTypeForCategory for reliable lookup

JSON keys in categoryTypeMap are strings, while catId from jQuery is always a string, but explicit coercion guards against mismatch:

function getTypeForCategory(catId)
{
    return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
}

2. Ensure you handle the includes compatibility

Array.prototype.includes is ES6+, if you need broader support replace with:

if ($.inArray(currentTemplate, templates) !== -1) {
    $template.val(currentTemplate);
} else {
    $template.val(templates[0] || '');
}

3. Clear formatting for heredoc

Make sure indentation within the heredoc (<<<js ... js;) does not introduce extra spaces.
Here is your slightly adjusted full method:

private function renderJS(
    string $allowedTemplatesJson,
    string $categoryTypeMapJson,
    string $currentTemplateJs,
    string $currentTypeJs
): void
{
    $uniqueId = uniqid('', false);
    $cacheKey = $this->_cacheKeyPrefix . $uniqueId . '_js_block_';
    $jsBlock = $this->getCachedJsBlock($cacheKey, function () use (
        $allowedTemplatesJson,
        $categoryTypeMapJson,
        $currentTemplateJs,
        $currentTypeJs
    ) {
        return <<<js
(function(\$) {
    \$(function() {
        var allowedTemplates = $allowedTemplatesJson;
        var categoryTypeMap = $categoryTypeMapJson;
        var \$category = \$('#content-category');
        var \$template = \$('#content-template');

        function getTypeForCategory(catId) {
            return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
        }

        function updateTemplateOptions(type) {
            var templates = allowedTemplates[type] || [];
            \$template.empty();

            if (templates.length === 0) {
                \$template.append(\$('<option>').val('').text('Select a template'));
                \$template.prop('disabled', true);
            } else {
                \$.each(templates, function(i, val) {
                    \$template.append(\$('<option>').val(val).text(val));
                });
                \$template.prop('disabled', false);
            }

            var currentTemplate = $currentTemplateJs;
            if (\$.inArray(currentTemplate, templates) !== -1) {
                \$template.val(currentTemplate);
            } else {
                \$template.val(templates[0] || '');
            }
        }

        function toggleFields(type, template) {
            console.log('toggleFields called with:', type, template);
            \$('#post-exhibition-fields').toggle(type === 'post' && template === 'exhibition');
            \$('#product-extra-fields').toggle(type === 'product');
            \$('#product-common-fields').toggle(type === 'product');
        }

        var initialCategoryId = \$category.val();
        var initialType = getTypeForCategory(initialCategoryId) || $currentTypeJs;

        if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0) {
            \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
            toggleFields(null, null);
        } else {
            updateTemplateOptions(initialType);
            var initialTemplate = \$template.val();
            toggleFields(initialType, initialTemplate);
        }

        \$category.on('change', function() {
            var catId = \$(this).val();

            if (!catId || !getTypeForCategory(catId)) {
                \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                toggleFields(null, null);
                return;
            }

            var type = getTypeForCategory(catId);
            updateTemplateOptions(type);
            var newTemplate = \$template.val();
            toggleFields(type, newTemplate);
        });

        \$template.on('change', function() {
            var template = \$(this).val();
            var type = getTypeForCategory(\$category.val()) || $currentTypeJs;
            toggleFields(type, template);
        });
    });
})(jQuery);
js;
    });

    $this->view->registerJs($jsBlock, \yii\web\View::POS_END);
}

Summary:

    This version explicitly converts catId to string when checking keys in JS.
    Uses jQuery $.inArray instead of Array.includes for better browser support.
    toggleFields logs to console for debugging.
    JS runs after DOM ready and jQuery loaded (POS_END).

If you want, I can help you with anything else or write a full minimal example based on this!

are you using jquery 3.6?

I don’t directly “use” jQuery versions myself—I provide code compatible with modern jQuery versions, including 3.6.x, which is the latest stable release as of now.

The code snippets I provide assume a standard jQuery 3.x environment, including features like .on(), .prop(), .empty(), and ES5+ JavaScript. The use of Array.prototype.includes in some snippets assumes ES6 support, which jQuery 3.6+ is typically used alongside, but if you require broader compatibility, I’ve suggested fallback to $.inArray().

If your Yii2 project is loading jQuery 3.6 (or any 3.x version), the provided code will work fine. To check which jQuery version your app loads, open the browser console and type:

jQuery.fn.jquery

or

$.fn.jquery

It will print the version string.

If you want to use or ensure jQuery 3.6 specifically, make sure your asset bundles or composer setup include this version, or you manually include it in your layout.

If you want me to help you confirm/change your Yii2 jQuery version or adjust code for a specific jQuery version, just say the word!

(function($)
{
    $(function()
    {
        var allowedTemplates = {"post":["article","exhibition","artist","catalog"],"product":["item","artwork","exhibition","catalog"]};
        var categoryTypeMap = {"1":"post","2":"post","3":"post","4":"product","5":"product","6":"post","7":"post","8":"post","9":"post","10":"product","11":"product","12":"product"};
        
        var $category = $('#content-category');
        var $template = $('#content-template');
        
        function getTypeForCategory(catId)
        {
            /* Convert catId to string for comparison because JSON keys are strings */
            return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
        }
        
        function updateTemplateOptions(type)
        {
            var templates = allowedTemplates[type] || [];
            $template.empty();
            
            if (templates.length === 0)
            {
                $template.append($('<option>').val('').text('Select a template'));
                $template.prop('disabled', true);
            }
            else
            {
                $.each(templates, function(i, val)
                {
                    $template.append($('<option>').val(val).text(val));
                });
                
                $template.prop('disabled', false);
            }
            
            var currentTemplate = "";
            
            /* Array.prototype.includes is ES6+ */
            if ($.inArray(currentTemplate, templates) !== -1)
            {
                $template.val(currentTemplate);
            }
            else
            {
                $template.val(templates[0] || '');
            }
        }
        
        function toggleFields(type, template)
        {
            console.log('toggleFields called with:', type, template);
            
            $('#post-exhibition-fields').toggle(type === 'post' && template === 'exhibition');
            $('#product-extra-fields').toggle(type === 'product');
            $('#product-common-fields').toggle(type === 'product');
        }
        
        var initialCategoryId = $category.val();
        var initialType = getTypeForCategory(initialCategoryId) || null;
        
        if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0)
        {
            $template.empty().append($('<option>').val('').text('Select a category first')).prop('disabled', true);
            toggleFields(null, null);
        }
        else
        {
            updateTemplateOptions(initialType);
            var initialTemplate = $template.val();
            toggleFields(initialType, initialTemplate);
        }
        
        $category.on('change', function()
        {
            var catId = $(this).val();
            
            if (!catId || !getTypeForCategory(catId))
            {
                $template.empty().append($('<option>').val('').text('Select a category first')).prop('disabled', true);
                toggleFields(null, null);
                
                return;
            }
            
            var type = getTypeForCategory(catId);
            updateTemplateOptions(type);
            var newTemplate = $template.val();
            toggleFields(type, newTemplate);
        });
        
        $template.on('change', function()
        {
            var template = $(this).val();
            var type = getTypeForCategory($category.val()) || null;
            toggleFields(type, template);
        });
        
    });
})(jQuery);

Does it look right? because nothing works now

The code you provided looks structurally sound and logically consistent to me. It correctly:

    Defines mappings from categories to types and templates.
    Sets up jQuery handlers for category and template changes.
    Updates template options and toggles form field visibility based on selections.

If "nothing works now," common causes to check are:

    Element IDs: Make sure the IDs content-category, content-template, post-exhibition-fields, product-extra-fields, and product-common-fields exist exactly as specified.

    JavaScript errors: Open the browser console and check for any JavaScript errors which would prevent this script from running.

    jQuery loaded before this script: This script depends on jQuery; verify jQuery is properly loaded before this script executes.

    Initial state of elements: Ensure the initial HTML state (e.g., the contents of the template dropdown) matches expectations so the JS can correctly update it.

    Scope and data availability: Check that your PHP variables outputting into Javascript (allowedTemplates and categoryTypeMap) are properly populated.

If you want, I can help you debug further or rewrite the code with detailed comments or enhanced debugging outputs to find the problem.

no matter what category I select, template remains disabled:

<?php
declare(strict_types=1);

namespace app\controllers;

// PHP built-in exception:
use \Throwable;

use Yii;
use yii\web\Controller;
use yii\web\Response;
use yii\filters\AccessControl;
use yii\filters\VerbFilter;
use yii\web\View;
use yii\base\InvalidArgumentException as YiiBaseInvalidArgumentException;
use yii\web\BadRequestHttpException as YiiWebBadRequestHttpException;
use yii\web\NotFoundHttpException as YiiWebNotFoundHttpException;
use yii\db\Exception as YiiDbException;
use yii\helpers\Json;

use app\controllers\BaseController;
use app\components\traits\CacheJsCssTrait;
use app\components\traits\PermissionAdminTrait;
use app\models\Content;
use app\models\ContentCategory;
use app\models\search\ContentSearch;
use app\models\forms\CartAddForm;
use app\widgets\forms\ModalInquiryForm;
use app\helpers\LogHelper;
use app\helpers\ParamHelper;

class ContentController extends BaseController
{
    public function actionCreate(): Response|string
    {
        $model = new Content();
        if (!$model)
        {
            throw new YiiWebNotFoundHttpException(\Yii::t('app', 'Content not found'));
        }
        
        $session = \Yii::$app->session;
        $request = \Yii::$app->request;
        
        if (($request->isPost) && ($model->load($request->post())))
        {
            if ($model->validate() && $model->save())
            {
                $session->setFlash('success', \Yii::t('app', 'Created successfully.'));
            
                return $this->redirect(['view', 'id' => $model->id]);
            }
        }
        else
        {
            // Pre-populate default data
            $model->loadDefaultValues();
        }
        
        // Prepare your PHP variables for JS
        $data = $this->getCategoryOptions(true);// need categoryTypeMap for update
        $allowedTemplatesJson = Json::encode(Content::getAllowedTemplatesByType());
        $categoryTypeMapJson = Json::encode($data['categoryTypeMap'] ?? []);
        $currentTemplateJs = Json::encode('');
        $currentTypeJs = Json::encode(null);
        
        // Render Jquery
        $this->renderJS($allowedTemplatesJson, $categoryTypeMapJson, $currentTemplateJs, $currentTypeJs);

        return $this->render('create', [
            'model' => $model,
            'allowedTemplatesByType' => Content::getAllowedTemplatesByType(),
            'categoryOptions' => $data['categoryOptions'],
            'categoryTypeMap' => $data['categoryTypeMap'],
            'contentSummaryLength' => $this->_contentSummaryLength,
            'mediaBlogImageRecSize' => $this->_mediaBlogImageRecSize,
            'mediaProductImageRecSize' => $this->_mediaProductImageRecSize,
        ]);
    }
    
    /**
    * Get category dropdown options and optionally the categoryTypeMap (categoryId => type).
    * @param bool $includeTypeMap Whether to include 'categoryTypeMap' in the return
    * @return array
    */
    private function getCategoryOptions(bool $includeTypeMap = true): array
    {
        $categories = ContentCategory::find()->all();
        
        if (!$categories)
        {
            return [
                'categoryOptions' => [],
                'categoryTypeMap' => $includeTypeMap ? [] : null,
            ];
        }
        
        // Build hierarchical and flat category list
        $hierarchicalCategories = ContentCategory::structureCategories($categories);
        $flatCategories = ContentCategory::flattenCategoriesDropdown($hierarchicalCategories);
        
        if (!is_array($flatCategories))
        {
            $flatCategories = [];
        }
        
        // Map integer type IDs to string keys expected in JS/toggle logic
        $typeLabels = [
            ContentCategory::TYPE_POST => 'post',
            ContentCategory::TYPE_PRODUCT => 'product',
            // Add other type mappings as needed
        ];
        
        // Build categoryTypeMap only if needed
        $categoryTypeMap = null;
        
        if ($includeTypeMap)
        {
            // Build categoryTypeMap with type strings (not numeric IDs)
            $categoryTypeMap = [];
            
            foreach ($categories as $category)
            {
                // Map numeric type to string type
                $categoryTypeMap[$category->id] = $typeLabels[$category->type] ?? null;
            }
        }
        
        return [
            'categoryOptions' => $flatCategories,
            'categoryTypeMap' => $categoryTypeMap,
        ];
    }
    
    private function renderJS(
        string $allowedTemplatesJson,
        string $categoryTypeMapJson,
        string $currentTemplateJs,
        string $currentTypeJs
    ): void
    {
        $uniqueId = uniqid('', false);// Create 13-char unique string based on time
        $cacheKey = $this->_cacheKeyPrefix . $uniqueId . '_js_block_';
        $jsBlock = $this->getCachedJsBlock($cacheKey, function () use (
            $uniqueId,
            $allowedTemplatesJson,
            $categoryTypeMapJson,
            $currentTemplateJs,
            $currentTypeJs
        )
        {
            return <<<js
            (function(\$)
            {
                \$(function()
                {
                    var allowedTemplates = $allowedTemplatesJson;
                    var categoryTypeMap = $categoryTypeMapJson;
                    
                    var \$category = \$('#content-category');
                    var \$template = \$('#content-template');
                    
                    function getTypeForCategory(catId)
                    {
                        /* Convert catId to string for comparison because JSON keys are strings */
                        return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
                    }
                    
                    function updateTemplateOptions(type)
                    {
                        var templates = allowedTemplates[type] || [];
                        \$template.empty();
                        
                        if (templates.length === 0)
                        {
                            \$template.append(\$('<option>').val('').text('Select a template'));
                            \$template.prop('disabled', true);
                        }
                        else
                        {
                            \$.each(templates, function(i, val)
                            {
                                \$template.append(\$('<option>').val(val).text(val));
                            });
                            
                            \$template.prop('disabled', false);
                        }
                        
                        var currentTemplate = $currentTemplateJs;
                        
                        /* Array.prototype.includes is ES6+ */
                        if (\$.inArray(currentTemplate, templates) !== -1)
                        {
                            \$template.val(currentTemplate);
                        }
                        else
                        {
                            \$template.val(templates[0] || '');
                        }
                    }
                    
                    function toggleFields(type, template)
                    {
                        console.log('toggleFields called with:', type, template);
                        
                        \$('#post-exhibition-fields').toggle(type === 'post' && template === 'exhibition');
                        \$('#product-extra-fields').toggle(type === 'product');
                        \$('#product-common-fields').toggle(type === 'product');
                    }
                    
                    var initialCategoryId = \$category.val();
                    var initialType = getTypeForCategory(initialCategoryId) || $currentTypeJs;
                    
                    if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0)
                    {
                        \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                        toggleFields(null, null);
                    }
                    else
                    {
                        updateTemplateOptions(initialType);
                        var initialTemplate = \$template.val();
                        toggleFields(initialType, initialTemplate);
                    }
                    
                    \$category.on('change', function()
                    {
                        var catId = \$(this).val();
                        
                        if (!catId || !getTypeForCategory(catId))
                        {
                            \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                            toggleFields(null, null);
                            
                            return;
                        }
                        
                        var type = getTypeForCategory(catId);
                        updateTemplateOptions(type);
                        var newTemplate = \$template.val();
                        toggleFields(type, newTemplate);
                    });
                    
                    \$template.on('change', function()
                    {
                        var template = \$(this).val();
                        var type = getTypeForCategory(\$category.val()) || $currentTypeJs;
                        toggleFields(type, template);
                    });
                    
                });
            })(jQuery);
            js;
        });
        
        $this->view->registerJs($jsBlock, View::POS_END);
    }
}

view code

use yii\bootstrap5\Html;
use yii\bootstrap5\ActiveForm;
use yii\widgets\DetailView;
use yii\helpers\ArrayHelper;
use yii\helpers\Url;

use app\models\Content;
use app\models\search\ContentSearch;
use app\widgets\TrumbowygJQry;
use app\helpers\ViewHelper;

/**
* Setup CategoryTypeMap + Template engine
*
* Ensure $categoryTypeMap is an array, even if not provided
* This map links category IDs to their corresponding content types (e.g., 'post', 'product')
*/
$categoryTypeMap = $categoryTypeMap ?? [];
// Get the currently selected category ID from the model, or null if none selected
$currentCategoryId = $model->category_id ?? null;
// Initialize variable to hold the content type related to the selected category
$currentType = null;

// If there is a selected category and it exists in the categoryTypeMap,
// set the currentType to the mapped content type of that category
if ($currentCategoryId && isset($categoryTypeMap[$currentCategoryId]))
{
    $currentType = $categoryTypeMap[$currentCategoryId];
}
// Otherwise, if no category is selected or it is not in the map,
// fall back to using the content type directly from the model (if available)
else
{
    $currentType = $model->type ?? null;
}

// Based on the determined content type, fetch the allowed templates for that type
// If currentType is null or not found in allowedTemplatesByType, set templates to empty array
$templatesForCurrentType = $currentType && isset($allowedTemplatesByType[$currentType]) 
    ? $allowedTemplatesByType[$currentType]
    : [];
?>


<?php
$form = ActiveForm::begin([
    'id' => 'content-form',
    'method' => 'post',
    'options' => ['class' => 'active-form mx-auto'],
]);
/*
<?= $form->field($model, 'category_id')->textInput(); ?>
<?= $form->field($model, 'template')->dropDownList(ContentSearch::getTemplateList(), ['prompt' => 'Select Template']) ?>
<?= $form->field($model, 'category_title')->textInput(['maxlength' => true]); ?>
<?= $form->field($model, 'status')->textInput(); ?>
<?= $form->field($model, 'title')->textInput(['maxlength' => true]); ?>
<?= $form->field($model, 'slug')->textInput(['maxlength' => true]); ?>
<?= $form->field($model, 'body')->textarea(['rows' => 6]); ?>
<?= $form->field($model, 'image_header')->textInput(['maxlength' => true]); ?>
<?= $form->field($model, 'meta_description')->textInput(['maxlength' => true]); ?>
<?= $form->field($model, 'meta_keywords')->textInput(['maxlength' => true]); ?>

<?= $form->field($model, 'artist')->textInput(); ?>
<?= $form->field($model, 'dimensions')->textInput(); ?>
<?= $form->field($model, 'medium')->textInput(); ?>
<?= $form->field($model, 'year')->textInput(); ?>
<?= $form->field($model, 'price')->textInput(); ?>
<?= $form->field($model, 'purchaseOptionsArray', [])->checkboxList([]); ?>
<?= $form->field($model, 'hide_price')->checkbox(); ?>
<?= $form->field($model, 'quantity')->textInput(); ?>
<?= $form->field($model, 'product_image_one')->textInput(['maxlength' => true]); ?>
<?= $form->field($model, 'product_image_two')->textInput(['maxlength' => true]); ?>
<?= $form->field($model, 'product_image_three')->textInput(['maxlength' => true]); ?>

<?= $form->field($model, 'created_by')->textInput(); ?>
<?= $form->field($model, 'updated_by')->textInput(); ?>
<?= $form->field($model, 'created_at')->textInput(); ?>
<?= $form->field($model, 'updated_at')->textInput(); ?>
*/ ?>

<ul class="nav justify-content-center mb-3">
<li class="nav-item ms-3"><?= Html::a(\Yii::t('app', 'view media'), ['media/index'], ['class' => 'nav-link']); ?></li>
</ul>


<div class="row">


<div class="col-md-4 mb-2">
<?php
/**
* Note: Due to limitations of standard HTML <select> elements, HTML content such as
* icons cannot be rendered directly within <option> elements. HTML dropdowns do not
* support rich content and will typically display such elements as raw text.
*/
echo  $form->field($model, 'category_id')->dropDownList($categoryOptions ?? [], [
    'class' => 'form-control square',
    'prompt'  => \Yii::t('app', 'select a category...')
])->label('Category')->hint(\Yii::t('app', 'optional')); ?>
</div><!-- .col-md-4 .mb-2 -->

<div class="col-md-4 mb-2">
<?= $form->field($model, 'template')->dropDownList($templatesForCurrentType ?: [],// empty if no current type
    [
        'prompt' => \Yii::t('app', 'select a template...'),
        'id' => 'content-template',
        'disabled' => true,// always start disabled on create; JS will enable later
    ]
); ?>
</div><!-- .col-md-4 .mb-2 -->

<div class="col-md-4 mb-2">
<?= $form->field($model, 'status')->dropDownList(Content::getStatusLabels(), [
    'class' => 'form-control square',
    'prompt' => \Yii::t('app', 'select a status...'),
])->label(\Yii::t('app', 'content status'))->hint(\Yii::t('app', 'required')); ?>
</div><!-- .col-md-4 .mb-2 -->


</div><!-- .row -->
<div class="row">


<div class="col-md-12 mb-2">
<?= $form->field($model, 'title')->textInput([
    'class' => 'form-control square',
    'maxlength' => true
])->hint(\Yii::t('app', 'required')); ?>
</div><!-- .col-md-12 .mb-2 -->


</div><!-- .row -->
<div class="row">


<div class="col-md-6 mb-2">
<?php
$label = \Yii::t('app', 'Description ({value} characters max)', ['value' => $contentSummaryLength]);
echo $form->field($model, 'meta_description')->textarea([
    'class' => 'form-control square',
    'rows' => 2,
])->label($label)->hint(\Yii::t('app', 'optional'));
?>
</div><!-- .col-md-6 .mb-2 -->

<div class="col-md-6 mb-2">
<?php
$label = \Yii::t('app', 'Keywords (keyword1, keyword2, keyword3)');
echo $form->field($model, 'meta_keywords')->textInput([
    'class' => 'form-control square',
    'maxlength' => true
])->label($label)->hint(\Yii::t('app', 'optional'));
?>
</div><!-- .col-md-6 .mb-2 -->


</div><!-- .row -->
<div class="row">


</div><!-- .row -->
<?php ActiveForm::end(); ?>

Thanks for sharing your full controller action and view code!

Your key issue: the template dropdown is always disabled on create, and selecting a category does not enable or populate it.
Why this happens

    In your controller actionCreate(), you encode data correctly and render the form.

    Your form renders the template dropdown with:

    'disabled' => true, // always disabled initially

    Your JavaScript code (registered via renderJS) should update and enable the template dropdown when the user selects a category by listening to the category's change event.

If the template dropdown remains disabled and empty after selecting a category, then the JavaScript code either:

    Is not executed at all,
    Has errors stopping its execution,
    Cannot find the elements by their IDs,
    The category IDs used in JS don't match those in the categoryTypeMap,
    Or the allowedTemplatesByType mapping keys do not match.

What you should do step-by-step
1. Verify your dropdown IDs in HTML

Make sure your category and template fields have exactly these IDs:

    Category dropdown: id="content-category"
    Template dropdown: id="content-template"

Your code shows:

$form->field($model, 'category_id')->dropDownList(..., ['class' => ..., 'prompt' => ..., /* no explicit id */])

You must explicitly set:

$form->field($model, 'category_id')->dropDownList(
    $categoryOptions ?? [],
    [
        'class' => 'form-control square',
        'prompt' => \Yii::t('app', 'select a category...'),
        'id' => 'content-category',      // <--- Add this
    ]
)->label('Category')->hint(\Yii::t('app', 'optional'));

Make sure you add 'id' => 'content-category' here.

Without this, your JS selector $('#content-category') will not find the element.
2. Check JavaScript console errors in your browser

Open dev tools (F12) and check the Console tab for errors which stop your JS from running.
3. In your controller, verify data matches expected format

    $categoryTypeMap: keys must match the string version of category IDs as used in HTML <select>.

    Example:

{
  "1": "post",
  "2": "post",
  "3": "product",
  ...
}

$allowedTemplatesByType:

    [
        'post' => [...],
        'product' => [...],
    ]

    If your JS expects string keys like 'post', make sure this matches what $categoryTypeMap returns.

4. Verify your JS is registered and runs after page has loaded

Your method renderJS is registering at View::POS_END, which is good.

Open console and add at start of your JS (inside renderJS):

console.log('JS loaded');

To verify JS runs.
5. Manually test category change event triggers in browser console

Open the console and run:

$('#content-category').trigger('change');

See if this calls your updateTemplateOptions and toggleFields with correct parameters (if you have console logs inside).
Summary fix for your form code, adding missing id for category select:

echo $form->field($model, 'category_id')->dropDownList($categoryOptions ?? [], [
    'class' => 'form-control square',
    'prompt'  => \Yii::t('app', 'select a category...'),
    'id' => 'content-category',  // <--- Make sure this is present!
])->label('Category')->hint(\Yii::t('app', 'optional'));

You may also want to add id explicitly for the template dropdown:

$form->field($model, 'template')->dropDownList($templatesForCurrentType ?: [],[
    'prompt' => \Yii::t('app', 'select a template...'),
    'id' => 'content-template',  // <--- Add this id!
    'disabled' => true,
]);

If after this, templates still do not enable or populate on category selection, share your browser console output (errors and logs), and I can help further troubleshoot.
TL;DR

    Add id="content-category" and id="content-template" in your dropdowns.
    Verify your JS loads and runs.
    Check console for JS errors.
    Confirm data passed from controller matches keys used in JS.

Feel free to ask if you want me to show exactly how to make these quick changes!

instead of using: product-extra-fields and post-exhibition-fields to hide and show feilds.. Couldnt I just add a class to a $field... for each different field, so this give me more options for layout design

Absolutely, you can absolutely use CSS classes on individual fields to show/hide them based on the current category type and template instead of relying on wrapping groups like #post-exhibition-fields or #product-extra-fields.
Benefits of using classes on fields:

    Fine-grained control: You can show/hide any specific field independently.
    Flexible layouts: You aren't constrained to grouping fields in container divs.
    Easier styling: CSS frameworks and grid layouts work better when fields aren’t always stuck inside fixed containers.
    Easier to add/remove specific fields without changing group containers.

How to implement this approach:
1. Add CSS classes to each field in your form

In your _form.php, when rendering a field, add a meaningful class like field-post, field-product, field-exhibition, etc., depending on the type and template it belongs to.

Example:

<?= $form->field($model, 'start_date', ['options' => ['class' => 'field-post field-exhibition']])->input('date') ?>
<?= $form->field($model, 'artist', ['options' => ['class' => 'field-product']])->textInput(['maxlength' => true]) ?>

You add classes to the wrapping div container of the field.
2. Adjust your JavaScript to toggle fields by class

Instead of toggling containers, toggle fields by class selectors based on type and template:

function toggleFields(type, template) {
    console.log('toggleFields called with:', type, template);

    // Hide all fields for post and product first
    $('.field-post, .field-product').hide();

    // Show fields that match current type
    if (type === 'post') {
        $('.field-post').show();

        // For post + exhibition, show additional fields
        if (template === 'exhibition') {
            $('.field-exhibition').show();
        }
    } else if (type === 'product') {
        $('.field-product').show();
    }
}

3. Organize your field classes logically

Example classes to add:
Field 	Classes 	Meaning
start_date 	field-post field-exhibition 	only for posts with "exhibition" template
artist 	field-product 	only for products
price 	field-product 	only for products
quantity 	field-product 	only for products
4. CSS Considerations

Since the default Bootstrap/Yii2 style shows/hides .form-group divs with the field- class, this approach integrates well and won’t mess with layout.
Summary

    Add descriptive CSS classes to each field wrapper.
    Use JS to show/hide these classes per selected type and template.
    This gives much more granular control and flexibility for your form layout and logic.

If you want I can prepare a concrete example of _form.php fields with classes added and matching updated JS toggle function. Just let me know!


Yes—you can absolutely add CSS classes to individual fields and use those classes in your JavaScript to show/hide fields dynamically. This approach gives you more granular control over form layout and behavior compared to toggling entire containers.
How to implement it:

1. Add classes to your form fields

For example, when rendering a field, add CSS classes indicating type and template:

<?= $form->field($model, 'start_date', ['options' => ['class' => 'field-post field-exhibition']])->input('date') ?>
<?= $form->field($model, 'artist', ['options' => ['class' => 'field-product']])->textInput(['maxlength' => true]) ?>

2. Update your JavaScript toggle function to show/hide fields by classes

function toggleFields(type, template) {
    // Hide all fields initially
    $('.field-post, .field-product').hide();

    // Show fields by type
    if (type === 'post') {
        $('.field-post').show();

        // Show extra for specific template
        if (template === 'exhibition') {
            $('.field-exhibition').show();
        }
    } else if (type === 'product') {
        $('.field-product').show();
    }
}

This approach lets you control visibility per field and supports complex layouts without relying on container divs.

If you want, I can help you refactor your existing form and JS to implement this!

return <<<js
            (function(\$)
            {
                \$(function()
                {
                    var allowedTemplates = $allowedTemplatesJson;
                    var categoryTypeMap = $categoryTypeMapJson;
                    
                    var \$category = \$('#content-category');
                    var \$template = \$('#content-template');
                    
                    function getTypeForCategory(catId)
                    {
                        /* Convert catId to string for comparison because JSON keys are strings */
                        return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
                    }
                    
                    function updateTemplateOptions(type)
                    {
                        var templates = allowedTemplates[type] || [];
                        \$template.empty();
                        
                        if (templates.length === 0)
                        {
                            \$template.append(\$('<option>').val('').text('Select a template'));
                            \$template.prop('disabled', true);
                        }
                        else
                        {
                            \$.each(templates, function(i, val)
                            {
                                \$template.append(\$('<option>').val(val).text(val));
                            });
                            
                            \$template.prop('disabled', false);
                        }
                        
                        var currentTemplate = $currentTemplateJs;
                        
                        /* Array.prototype.includes is ES6+ */
                        if (\$.inArray(currentTemplate, templates) !== -1)
                        {
                            \$template.val(currentTemplate);
                        }
                        else
                        {
                            \$template.val(templates[0] || '');
                        }
                    }
                    
                    function toggleFields(type, template)
                    {
                        console.log('toggleFields called with:', type, template);
                        
                        \$('#post-exhibition-fields').toggle(type === 'post' && template === 'exhibition');
                        \$('#product-extra-fields').toggle(type === 'product');
                        \$('#product-common-fields').toggle(type === 'product');
                    }
                    
                    var initialCategoryId = \$category.val();
                    var initialType = getTypeForCategory(initialCategoryId) || $currentTypeJs;
                    
                    if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0)
                    {
                        \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                        toggleFields(null, null);
                    }
                    else
                    {
                        updateTemplateOptions(initialType);
                        var initialTemplate = \$template.val();
                        toggleFields(initialType, initialTemplate);
                    }
                    
                    \$category.on('change', function()
                    {
                        var catId = \$(this).val();
                        
                        if (!catId || !getTypeForCategory(catId))
                        {
                            \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                            toggleFields(null, null);
                            
                            return;
                        }
                        
                        var type = getTypeForCategory(catId);
                        updateTemplateOptions(type);
                        var newTemplate = \$template.val();
                        toggleFields(type, newTemplate);
                    });
                    
                    \$template.on('change', function()
                    {
                        var template = \$(this).val();
                        var type = getTypeForCategory(\$category.val()) || $currentTypeJs;
                        toggleFields(type, template);
                    });
                    
                });
            })(jQuery);
            js;

so what would I need to change?

Your JavaScript block looks solid and logically sound for dynamically updating the template dropdown and toggling fields based on category and template selections. However, to ensure it works correctly in your Yii2 setup and interacts properly with your PHP variables and HTML structure, here are the key things you might want to check or change if needed:
1. Ensure PHP variables provide correct JSON

Make sure these variables passed into the JS are properly JSON-encoded and reflect the current data:

    $allowedTemplatesJson: Should be a JSON object with keys matching type strings ("post", "product") and arrays of templates as values.
    $categoryTypeMapJson: Should be a JSON object mapping category IDs (as strings) to the type strings used above.
    $currentTemplateJs: Should be a properly JSON-encoded string indicating the current template if any. Use Json::encode($model->template ?? '').
    $currentTypeJs: Should be JSON of current type string or empty string/null if none. Use Json::encode($currentType ?? '').

2. Make sure your HTML contains elements with the expected IDs

    Dropdowns with IDs:
        #content-category
        #content-template
    Containers for fields with IDs:
        #post-exhibition-fields
        #product-extra-fields
        #product-common-fields

If any of these are missing or IDs don’t match exactly, your JS will fail to find them.
3. Update JS to handle type coercion in getTypeForCategory

Since JSON keys are strings, but HTML select values may be numbers (or strings), coerce the catId to a string before lookup:

function getTypeForCategory(catId) {
    return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
}

This helps avoid mismatches if category ID types differ.
4. Optional: Use $.inArray instead of includes to support older browsers

Your code already does this right (you wrote $.inArray()), but confirm currentTemplate is initialized correctly.
5. Ensure your PHP template renders the dropdowns disabled by default when templates are empty

In your _form.php:

<?= $form->field($model, 'template')->dropDownList(
    $templatesForCurrentType ?: [],
    [
        'prompt' => \Yii::t('app', 'select a template...'),
        'id' => 'content-template',
        'disabled' => empty($templatesForCurrentType),
    ]
) ?>

This aligns with JS that enables the dropdown and populates it only when a category is selected.
6. Add console logs temporarily to verify everything

Inside your JS functions add console.log() like:

console.log('Category ID:', initialCategoryId, 'Type:', initialType);
console.log('Templates for type:', allowedTemplates[initialType]);
console.log('Templates in updateTemplateOptions:', templates);
console.log('Toggle fields called with:', type, template);

Make sure these logs appear as expected in the browser console.
Summary

You do not likely need to change anything major with your existing JS code, except:

    Ensure PHP variables are properly JSON encoded.
    Make sure IDs in HTML match.
    Ensure strings and types sync (category IDs as strings).
    Add debugging logs to track flow.
    Ensure your form initially disables templates and your JS enables as expected.

If you want, I can write you a fully integrated copy-paste-ready PHP + JS snippet with sample data for your context. Let me know!

I want to change this:

return <<<js
            (function(\$)
            {
                \$(function()
                {
                    var allowedTemplates = $allowedTemplatesJson;
                    var categoryTypeMap = $categoryTypeMapJson;
                    
                    var \$category = \$('#content-category');
                    var \$template = \$('#content-template');
                    
                    function getTypeForCategory(catId)
                    {
                        /* Convert catId to string for comparison because JSON keys are strings */
                        return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
                    }
                    
                    function updateTemplateOptions(type)
                    {
                        var templates = allowedTemplates[type] || [];
                        \$template.empty();
                        
                        if (templates.length === 0)
                        {
                            \$template.append(\$('<option>').val('').text('Select a template'));
                            \$template.prop('disabled', true);
                        }
                        else
                        {
                            \$.each(templates, function(i, val)
                            {
                                \$template.append(\$('<option>').val(val).text(val));
                            });
                            
                            \$template.prop('disabled', false);
                        }
                        
                        var currentTemplate = $currentTemplateJs;
                        
                        /* Array.prototype.includes is ES6+ */
                        if (\$.inArray(currentTemplate, templates) !== -1)
                        {
                            \$template.val(currentTemplate);
                        }
                        else
                        {
                            \$template.val(templates[0] || '');
                        }
                    }
                    
                    function toggleFields(type, template)
                    {
                        console.log('toggleFields called with:', type, template);
                        
                        \$('#post-exhibition-fields').toggle(type === 'post' && template === 'exhibition');
                        \$('#product-extra-fields').toggle(type === 'product');
                        \$('#product-common-fields').toggle(type === 'product');
                    }
                    
                    var initialCategoryId = \$category.val();
                    var initialType = getTypeForCategory(initialCategoryId) || $currentTypeJs;
                    
                    if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0)
                    {
                        \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                        toggleFields(null, null);
                    }
                    else
                    {
                        updateTemplateOptions(initialType);
                        var initialTemplate = \$template.val();
                        toggleFields(initialType, initialTemplate);
                    }
                    
                    \$category.on('change', function()
                    {
                        var catId = \$(this).val();
                        
                        if (!catId || !getTypeForCategory(catId))
                        {
                            \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                            toggleFields(null, null);
                            
                            return;
                        }
                        
                        var type = getTypeForCategory(catId);
                        updateTemplateOptions(type);
                        var newTemplate = \$template.val();
                        toggleFields(type, newTemplate);
                    });
                    
                    \$template.on('change', function()
                    {
                        var template = \$(this).val();
                        var type = getTypeForCategory(\$category.val()) || $currentTypeJs;
                        toggleFields(type, template);
                    });
                    
                });
            })(jQuery);
            js;

to handle things like so:
field($model, 'start_date', ['options' => ['class' => 'field-post field-exhibition']])->input('date') ?> field($model, 'artist', ['options' => ['class' => 'field-product']])->textInput(['maxlength' => true]) ?>

instead of :

Got it! You want to switch from toggling entire containers by ID to showing/hiding individual form fields based on CSS classes like .field-post, .field-exhibition, .field-product, etc.

Below is your updated JavaScript inside the same heredoc style to toggle fields by class names on the wrapper DIVs Yii generates for each form field, instead of using container IDs.
Updated JS for toggling fields by classes on .field-post, .field-exhibition, .field-product:

return <<<js
(function(\$)
{
    \$(function()
    {
        var allowedTemplates = $allowedTemplatesJson;
        var categoryTypeMap = $categoryTypeMapJson;

        var \$category = \$('#content-category');
        var \$template = \$('#content-template');

        function getTypeForCategory(catId)
        {
            return categoryTypeMap.hasOwnProperty(String(catId)) ? categoryTypeMap[String(catId)] : null;
        }

        function updateTemplateOptions(type)
        {
            var templates = allowedTemplates[type] || [];
            \$template.empty();

            if (templates.length === 0)
            {
                \$template.append(\$('<option>').val('').text('Select a template'));
                \$template.prop('disabled', true);
            }
            else
            {
                \$.each(templates, function(i, val)
                {
                    \$template.append(\$('<option>').val(val).text(val));
                });

                \$template.prop('disabled', false);
            }

            var currentTemplate = $currentTemplateJs;

            if (\$.inArray(currentTemplate, templates) !== -1)
            {
                \$template.val(currentTemplate);
            }
            else
            {
                \$template.val(templates[0] || '');
            }
        }

        function toggleFields(type, template)
        {
            console.log('toggleFields called with:', type, template);

            // Hide all post and product related fields
            \$('.field-post, .field-exhibition, .field-product').hide();

            // Show fields for post type
            if (type === 'post')
            {
                \$('.field-post').show();

                // Show additionally fields specific to "exhibition" template
                if (template === 'exhibition')
                {
                    \$('.field-exhibition').show();
                }
            }
            // Show fields for product type
            else if (type === 'product')
            {
                \$('.field-product').show();
            }
        }

        var initialCategoryId = \$category.val();
        var initialType = getTypeForCategory(initialCategoryId) || $currentTypeJs;

        if (!categoryTypeMap || Object.keys(categoryTypeMap).length === 0)
        {
            \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
            toggleFields(null, null);
        }
        else
        {
            updateTemplateOptions(initialType);
            var initialTemplate = \$template.val();
            toggleFields(initialType, initialTemplate);
        }

        \$category.on('change', function()
        {
            var catId = \$(this).val();

            if (!catId || !getTypeForCategory(catId))
            {
                \$template.empty().append(\$('<option>').val('').text('Select a category first')).prop('disabled', true);
                toggleFields(null, null);

                return;
            }

            var type = getTypeForCategory(catId);
            updateTemplateOptions(type);
            var newTemplate = \$template.val();
            toggleFields(type, newTemplate);
        });

        \$template.on('change', function()
        {
            var template = \$(this).val();
            var type = getTypeForCategory(\$category.val()) || $currentTypeJs;
            toggleFields(type, template);
        });
    });
})(jQuery);
js;

What needs to be done in your PHP _form.php file:

Add meaningful CSS classes to the field wrapper options (<div class="form-group field-..."> container), e.g.:

<?= $form->field($model, 'start_date', ['options' => ['class' => 'field-post field-exhibition']])->input('date') ?>
<?= $form->field($model, 'artist', ['options' => ['class' => 'field-product']])->textInput(['maxlength' => true]) ?>
<?= $form->field($model, 'price', ['options' => ['class' => 'field-product']])->textInput() ?>

This way, your JS hides/shows form fields by adding or removing visibility to the entire wrapper div of each field.
Advantages

    You can control display on per-field basis, offering granular flexibility.
    Avoids grouping fields in containers; easier to design complex form layouts.
    Works seamlessly with Yii’s markup.

If you want, I can provide a full working example of the PHP form snippet and JS integrated with these classes — just let me know!

write a comment for how the jquery works and what classes to use

Certainly! Here's a clear comment you can include (e.g., above your JavaScript block) explaining how the jQuery works and what CSS classes to apply to your form fields:

/*
 * JavaScript dynamic form behavior explanation:
 *
 * This script dynamically updates the available template options and toggles the visibility 
 * of individual form fields based on the currently selected content category and template.
 *
 * How it works:
 * 1. When the page loads or when the category dropdown changes:
 *    - The script determines the content "type" linked to the selected category using `categoryTypeMap`.
 *    - Based on this type, it populates the template dropdown with allowed templates.
 *    - It enables the template dropdown if templates are available or disables it otherwise.
 *    - It shows or hides specific form fields depending on the selected type and template.
 *
 * 2. When the template dropdown changes:
 *    - The script updates the visibility of fields that depend on the selected template.
 *
 * CSS Classes to control field visibility:
 * - Apply the class `.field-post` to all form fields that should be shown for content type "post".
 * - Apply the class `.field-product` to all form fields that should be shown for content type "product".
 * - Apply the class `.field-exhibition` to fields shown only when the template is "exhibition" (usually for post type).
 *
 * Examples:
 * <?= $form->field($model, 'start_date', ['options' => ['class' => 'field-post field-exhibition']]) ?>
 * - Shows 'start_date' field only if content type is 'post' and template is 'exhibition'.
 *
 * <?= $form->field($model, 'artist', ['options' => ['class' => 'field-product']]) ?>
 * - Shows 'artist' field only if content type is 'product'.
 *
 * This approach allows fine-grained control of form field visibility without relying on grouping 
 * fields inside containers, enabling more flexible layouts.
 */

Feel free to place this comment above your JS code or in your view file for clarity.

1 Post News news
2 Post Updates updates
3 Post Exhibition exhibition
4 Post Current current
5 Post Upcoming upcoming
6 Post Past past
7 Post Artists artists
8 Product Artwork artwork

is example of the content category. im wondering if I should add the option for templates and what is allowed per category, as checkboxes options

Yes, adding template options per category as checkboxes or a similar UI in your admin interface can be very beneficial, especially if:

    You want fine-grained control of what templates are allowed per individual category instead of categorizing restrictions only by type (Post vs Product).
    Different categories under the same type might have different allowed templates. For example, the News category might allow only 'article', 'news' templates, while Exhibition allows 'exhibition'.

Benefits of per-category template settings:

    Flexible control: Customize template availability for each category.
    Future-proof: Adding new templates won’t require changing global allowedTemplatesByType logic.
    Better UX: Content creators see only relevant templates per category.

How to implement this:
1. Add template options to each ContentCategory

    Add a field (e.g., a json or string field) in your ContentCategory database table that stores the list of allowed templates for that category.

Example schema addition:

    allowed_templates (JSON or TEXT): ["article","exhibition","catalog"]

2. Admin UI to select allowed templates per category

    In your category management form, add a checkbox list of available templates so admins can select which templates are allowed for that category.

3. On save, store selected templates for that category

    Save these selections in the newly added database field.

4. Modify your content form to load allowed templates dynamically from the selected category

    When the user selects a category in content creation, load the allowed templates from the category (ideally via AJAX for performance and flexibility).
    Populate the template dropdown based on allowed templates for that category instead of or in addition to your fixed global allowedTemplatesByType.

5. (Optional) Cache or pre-load templates per category in PHP if performance is critical.
Things to consider:

    If you have many categories, it makes sense to load templates asynchronously instead of passing all data on each page load.
    Keep the global allowedTemplatesByType as fallback or default sets for categories without explicit settings.
    Update content validation rules to ensure selected template conforms to the allowed templates of its category.

Summary
Option 	Pros 	Cons
Use fixed templates by type 	Simple, easy to maintain 	Less granular control
Store allowed templates per category 	More flexible, category-specific control 	More complex UI, needs AJAX or caching

If you want, I can help you sketch the database migration, admin form checkbox UI, and the AJAX logic for loading templates per category.

Would you like me to?

namespace app\models;

class ContentCategory extends ActiveRecord
{
    const TYPE_POST = 1;
    const TYPE_PRODUCT = 2;
    
    public array $children = [];
    
    /**
    * Used to track category level for display/indentation purposes.
    * @return int
    *
    * Note: This is NOT a database attribute.
    */
    public int $level;

    public static function tableName(): string
    {
        return '{{%content_category}}';
    }
    
    public function rules(): array
    {
        return [
            /**
            * Rules
            * Rules are handled by either app\models\forms\** for user access validation, or
            * handled directly within the model and than view file skipping form model validation
            * for administration only.
            */
            [['title'], 'required'],
            
            
            [['parent_id', 'type', 'created_by', 'updated_by', 'created_at', 'updated_at'], 'integer'],
            [['title', 'slug'], 'string', 'max' => 255],
            [['slug'], 'unique'],
            
            ['type', 'default', 'value' => self::TYPE_POST],
            ['type', 'in', 'range' => [
                self::TYPE_POST,
                self::TYPE_PRODUCT,
            ]],
            
            // Ensures `parent_id` in this model refers to an existing `id` in the ContentCategory model.
            [['parent_id'], 'exist', 'skipOnError' => true, 'targetClass' => self::class, 'targetAttribute' => ['parent_id' => 'id']],
            
            /**
            * BlameableBehavior
            * @url https://www.yiiframework.com/doc/api/2.0/yii-behaviors-blameablebehavior
            */
            [['created_by'], 'exist', 'skipOnError' => true, 'targetClass' => User::class, 'targetAttribute' => ['created_by' => 'id']],
            [['updated_by'], 'exist', 'skipOnError' => true, 'targetClass' => User::class, 'targetAttribute' => ['updated_by' => 'id']],
        ];
    }
    
    public function attributeLabels(): array
    {
        return [
            'id' => \Yii::t('app', 'ID'),
            'type' => \Yii::t('app', 'Type'),
            'title' => \Yii::t('app', 'Title'),
            'slug' => \Yii::t('app', 'Slug'),
            'parent_id' => \Yii::t('app', 'Parent ID'),
            'created_by' => \Yii::t('app', 'Created By'),
            'updated_by' => \Yii::t('app', 'Updated By'),
            'created_at' => \Yii::t('app', 'Created At'),
            'updated_at' => \Yii::t('app', 'Updated At'),
        ];
    }
    
    public function beforeSave($insert): bool
    {
        if (!parent::beforeSave($insert))
        {
            return false;
        }
        
        // @url https://www.yiiframework.com/doc/api/2.0/yii-helpers-htmlpurifier
        $purifier = PurifierHelper::purifier();
        $this->title = $purifier->purify($this->title);
        $this->slug = $purifier->purify($this->slug);
        $this->parent_id = $purifier->purify($this->parent_id);
        
        return true;
    }
    
    public function afterSave($insert, $changedAttributes)
    {
        parent::afterSave($insert, $changedAttributes);
        
        // If this is an update (not a new record insert) and the 'type' attribute has changed
        if (!$insert && isset($changedAttributes['type']))
        {
            \Yii::$app->db->createCommand()
                ->update('{{%content}}', ['type' => $this->type], ['category_id' => $this->id])
                ->execute();
        }
    }
    
    public static function getTypeList(): array
    {
        return [
            self::TYPE_POST => \Yii::t('app', 'Post'),
            self::TYPE_PRODUCT => \Yii::t('app', 'Product'),
        ];
    }
    
    public function getTypeLabel(): string
    {
        return self::getTypeList()[$this->type] ?? \Yii::t('app', 'Unknown');
    }
    
    public function getParent(): ActiveQuery
    {
        return $this->hasOne(self::class, ['id' => 'parent_id']);
    }
    
    public function getChildren(): ActiveQuery
    {
        return $this->hasMany(self::class, ['parent_id' => 'id']);
    }
    
    public function getSiblings(): ActiveQuery
    {
        return self::find()
            ->where(['parent_id' => $this->parent_id])
            ->andWhere(['!=', 'id', $this->id])
            ->all();
    }
    
    public static function findRoots(): ActiveQuery|array
    {
        return self::find()->where(['parent_id' => null])->all();
    }
    
    public static function findAllCategories(): array
    {
        return self::find()->orderBy(['parent_id' => SORT_ASC, 'id' => SORT_ASC])->all();
    }
    
    public static function structureCategories(array $categories): array
    {
        $grouped = [];
        foreach ($categories as $category)
        {
            $grouped[$category->parent_id][] = $category;
        }
        
        return self::buildCategoryTree($grouped, null);
    }
    
    private static function buildCategoryTree(array &$grouped, int|null $parentId = null): array
    {
        $result = [];
        if (isset($grouped[$parentId]))
        {
            foreach ($grouped[$parentId] as $category)
            {
                $children = self::buildCategoryTree($grouped, $category->id);
                if ($children)
                {
                    $category->children = $children;// Adding children to the category.
                }
                
                $result[] = $category;
            }
        }
        
        return $result;
    }
    
    public static function flattenCategoriesGridView(array $categories, int $level = 0): array
    {
        $result = [];
        foreach ($categories as $category)
        {
            // Create a copy to avoid modifying the original models.
            $categoryCopy = clone $category;
            
            // Store the current level for use in view indentation / icon rendering
            $categoryCopy->level = $level;
            
            $result[] = $categoryCopy;
            
            if (!empty($category->children))
            {
                $result = array_merge($result, self::flattenCategoriesGridView($category->children, $level + 1));
            }
        }
        
        return $result;
    }
    
    public static function flattenCategoriesDropdown(array $categories, string $prefix = ''): array
    {
        $list = [];
        foreach ($categories as $category)
        {
            $list[$category->id] = $prefix . $category->title;
            
            if (isset($category->children))
            {
                $list += self::flattenCategoriesDropdown($category->children, $prefix . '= ');
            }
        }
        
        return $list;
    }
    
    public function getContentCategories(): ActiveQuery
    {
        return $this->hasMany(self::class, ['parent_id' => 'id']);
    }
    
    public function getContent(): ActiveQuery
    {
        return $this->hasMany(Content::class, ['category_id' => 'id']);
    }
    
    public function getCreatedBy(): ActiveQuery
    {
        return $this->hasOne(User::class, ['id' => 'created_by']);
    }
    
    public function getUpdatedBy(): ActiveQuery
    {
        return $this->hasOne(User::class, ['id' => 'updated_by']);
    }
}

Content activeRecord

namespace app\models;

class Content extends ActiveRecord
{
    // Templates (adjust as needed)
    public static $templates = ['item', 'artwork', 'article', 'exhibition', 'artist', 'catalog'];
    
    // Allowed templates per type
    protected static array $allowedTemplatesByType = [
        'post' => ['article', 'exhibition', 'artist', 'catalog'],
        'product' => ['item', 'artwork', 'exhibition', 'catalog'],
        //ContentCategory::TYPE_POST => ['article', 'exhibition', 'artist', 'catalog'],
        //ContentCategory::TYPE_PRODUCT => ['artwork', 'exhibition', 'item', 'catalog'],
        //ContentCategory::TYPE_CATALOG => [],// no templates or as needed
    ];
    
    public static function tableName(): string
    {
        return '{{%content}}';
    }
    
    public function scenarios(): array
    {
        $baseAttributes = [
            'type', 'template', 'category_id', 'category_title', 'status', 'title', 
            'slug', 'body', 'image_header', 'meta_description', 'meta_keywords',
            
            /**
            * Handled by TimestampBehavior
            'created_at', 'updated_at',//*/
            
            /**
            * Handled by BlameableBehavior
            'created_by', 'updated_by',//*/
        ];
        
        // Add purchaseOptionsArray here because it's used virtually
        $baseAttributes[] = 'purchaseOptionsArray';
        
        return [
            /**
            * Base type-only fallback scenarios for safety
            *
            * Note: array_merge function will append the scenario rules to the base rules, but 
            * it doesn't handle potential conflicts or overwriting of rules. 
            */
            ContentCategory::TYPE_POST => $baseAttributes,
            ContentCategory::TYPE_PRODUCT => array_merge($baseAttributes, [
                'artist', 'dimensions', 'medium', 'year', 
                'price', 'purchase_options', 'hide_price', 'quantity', 
                'product_image_one', 'product_image_two', 'product_image_three',
            ]),
            //ContentCategory::TYPE_CATALOG => $baseAttributes,
            
            /**
            * Post type + template scenarios for specific validation
            */
            'post_article' => $baseAttributes,
            'post_exhibition' => array_merge($baseAttributes, [
                'start_date', 'end_date',
            ]),
            'post_catalog' => $baseAttributes,
            
            /**
            * Product type + template scenario
            */
            'product_artwork' => array_merge($baseAttributes, [
                'artist', 'dimensions', 'medium', 'year',
                'price', 'purchase_options', 'hide_price', 'quantity', 
                'product_image_one', 'product_image_two', 'product_image_three',
            ]),
            'product_item' => array_merge($baseAttributes, [
                'artist',
                'price', 'purchase_options', 'quantity', 
                'product_image_one', 'product_image_two', 'product_image_three',
            ]),
            'product_catalog' => $baseAttributes,
            
            /**
            * Default
            */
            'default' => $baseAttributes,
        ];
    }
    
    public function rules(): array
    {
        /**
        * Rules
        * Rules are handled by either app\models\forms\** for user access validation, or
        * handled directly within the model and than view file skipping form model validation
        * for administration only.
        */
        $rules = [
            /**
            * Required
            */
            [['type', 'template', 'category_id', 'status', 'title', 'body'
                /* 'created_by', 'created_at' - handled by BlameableBehavior */], 'required'],
            
            /**
            * Integers
            * Note: Price is handled as a float/string until custom validation. See below.
            */
            [['category_id', 'status', 'year', 'quantity', /*'price'*,
                'purchase_options', Note: Empty int until declared via purchaseOptionsArray */
                'created_by', 'updated_by', 'created_at', 'updated_at'], 'integer'],
            
            /**
            * Strings
            */
            [['body', 'template', 'meta_description', 'meta_keywords', 'category_title'], 'string'],
            [['title', 'artist', 'dimensions', 'medium', 'category_title', 'meta_keywords', 'slug'], 'string', 'max' => 255],
            [['image_header','product_image_one', 'product_image_two', 'product_image_three'], 'string', 'max' => 2000],
            ['meta_description', 'string', 'max' => $this->_contentSummaryLength],
            ['template', 'string', 'max' => 50],
            
            /**
            * Boolean
            */
            ['hide_price', 'boolean'],
            ['hide_price', 'default', 'value' => false],
            
            /**
            * Safe
            */
            ['purchaseOptionsArray', 'safe'],// Allow purchaseOptionsArray for form binding as safe
            
            /**
            * Defaults
            */
            ['status', 'default', 'value' => self::STATUS_DRAFT],
            ['status', 'in', 'range' => [self::STATUS_DRAFT, self::STATUS_PUBLISH], 
                'when' => fn($model) => $model->type === ContentCategory::TYPE_POST],
            ['status', 'in', 'range' => [self::STATUS_DRAFT, self::STATUS_PUBLISH, self:: STATUS_SOLDOUT], 
                'when' => fn($model) => $model->type === ContentCategory::TYPE_PRODUCT],
            ['type', 'default', 'value' => ContentCategory::TYPE_POST],
            ['template', 'default', 'value' => 'article', 'when' => fn($model) => $model->type === ContentCategory::TYPE_POST],
            ['template', 'default', 'value' => 'item', 'when' => fn($model) => $model->type === ContentCategory::TYPE_PRODUCT],
            ['purchase_options', 'default', 'value' => self::PURCHASE_OPTIONS_CART | self::PURCHASE_OPTIONS_INQUIRE],
            
            /**
            * Custom validations 
            * A rule must specify both attribute names and validator type
            */
            [['template'], 'validateTemplateByType'],
            [['meta_description'], 'summaryLength'],
            //[['price'], 'validateMoney', 'skipOnError' => true],// TODO
            [['purchaseOptionsArray'], 'validatePurchaseOptions'],// Handled by getter and setter
            
            /**
            * Validation messages within form
            */
            [['price'], 'match', 'pattern' => '/^\d+(\.\d{1,2})?$/', 
                'message' => \Yii::t('app', 'The price must be a valid decimal number with up to two decimal places.')
            ],
            [['price'], 'number', 'min' => 2.00, 'max' => 5000000.00, 
                'message' => \Yii::t('app', 'The price must be a valid number between $2.00 and $5,000,000.00.')
            ],
            [['product_image_one', 'product_image_two', 'product_image_three'], 'url', 'skipOnEmpty' => true, 
                'message' => \Yii::t('app', 'Product Image URL is not valid.')],
            
            /**
            * Relationships
            */
            ['category_id', 'exist', 'skipOnEmpty' => false, 'skipOnError' => true, 'targetClass' => ContentCategory::class, 
                'targetAttribute' => ['category_id' => 'id'], 'message' => \Yii::t('app', 'Please select a valid category.')],
                
            ['created_by', 'exist', 'skipOnError' => true, 'targetClass' => User::class, 'targetAttribute' => ['created_by' => 'id']],
            ['updated_by', 'exist', 'skipOnError' => true, 'targetClass' => User::class, 'targetAttribute' => ['updated_by' => 'id']],
        ];
        
        $rulesByScenario = [
            /**
            * Post + exhibition requires start and end date maybe (example)
            */
            'post_exhibition' => [
                [['start_date', 'end_date'], 'required'],
            ],
            /**
            * Product specific validations
            */
            'product_artwork' => [
                [['artist', 'price', 'purchase_options', 'quantity', 'product_image_one'], 'required'],
            ],
            'product_item' => [
                [['price', 'quantity', 'purchase_options', 'product_image_one'], 'required'],
            ],
            
        ];
        
        /**
        * Merge rules: rules + scenario rules if any
        *
        * Note: array_merge function will append the scenario rules to the base rules, but it 
        * doesn't handle potential conflicts or overwriting of rules. 
        */
        $mergedRules = array_merge($rules, $rulesByScenario[$this->scenario] ?? []);
        //\yii\helpers\VarDumper::dump($mergedRules, 10, true);// TODO Debug scenarios tool
        
        return $mergedRules;
    }
    
    public function validateTemplateByType($attribute, $params = []): void
    {
        // Can't validate without type set
        if (!$this->type)
        {
            return;
        }
        
        $allowedTemplates = self::$allowedTemplatesByType[$this->type] ?? [];
        
        if ($this->$attribute !== null && !in_array($this->$attribute, $allowedTemplates, true))
        {
            $this->addError(
                $attribute,
                \Yii::t('app', 'The selected template "{template}" is not allowed for type "{type}".', [
                    'template' => $this->$attribute,
                    'type' => $this->type
                ])
            );
            
            return;
        }
    }
    
    public function beforeValidate(): bool
    {
        if (!parent::beforeValidate())
        {
            return false;
        }
        
        /**
        * Content "category_id" and ContentCategory "id" match
        * This method checks the relationship between Content and ContentCategory ID's
        * matches.
        */
        if ($this->category_id)
        {
            // Try to get the related category model: either from the relation already loaded, or from DB
            $category = $this->category ?? ContentCategory::findOne($this->category_id);
            
            if ($category)
            {
                $this->type = $category->type;
            }
        }
        
        /**
        * Set scenario automatically based on `type` and `template` to ensure validation 
        * rules apply correctly.
        */
        if ($this->type && $this->template)
        {
            // Construct the combined scenario name by concatenating type and template with an underscore
            // For example: 'product_artwork', 'post_exhibition'
            $combinedScenario = $this->type . '_' . $this->template;
            
            // Check if scenario exists: use combined, else fallback to type or 'default'
            if (isset($this->scenarios()[$combinedScenario]))
            {
                // If the combined scenario exists, set it as the current scenario
                $this->setScenario($combinedScenario);
            }
            // If combined scenario does not exist, check if a scenario matching just the type exists
            elseif (isset($this->scenarios()[$this->type]))
            {
                // Set the scenario to the type-only scenario (e.g., 'product' or 'post')
                $this->setScenario($this->type);
            }
            // If neither combined nor type-only scenario exists,
            else
            {
                // TODO Fallback to a default scenario to prevent validation errors
                $this->setScenario('default');
            }
        }
        // If only 'type' is set (no template)
        elseif ($this->type)
        {
            // Set the scenario to the type scenario
            $this->setScenario($this->type);
        }
        // If neither 'type' nor 'template' is set,
        else
        {
            // TODO Set a generic default scenario so validation can still proceed without errors
            $this->setScenario('default');
        }
        
        /**
        * Purchase Options Array to Bitmask
        * Convert purchaseOptionsArray from form into bitmask int before validation.
        */
        if ($this->_purchaseOptionsArray !== null)
        {
            $this->purchase_options = $this->arrayToBitmask($this->_purchaseOptionsArray);
        }
        elseif (is_array($this->purchase_options))
        {
            // Defensive: convert in case purchase_options is array (usually from form POST)
            $this->purchase_options = $this->arrayToBitmask($this->purchase_options);
        }
        else
        {
            // Ensure integer type
            $this->purchase_options = (int) $this->purchase_options;
        }
        
        return true;
    }
    
    public function beforeSave($insert): bool
    {
        if (!parent::beforeSave($insert))
        {
            return false;
        }
        
        /**
        * Category Title
        * Auto add Content $content->category_title assigned with 
        * ContentCategory $contentCategory->title
        */
        if ($this->getCategory()->one() && $this->category->title !== null)
        {
            $this->category_title = $this->category->title;
        }
        
        /**
        * Category ID
        * Check if the 'category_id' attribute has changed in this save only want 
        * to update the post's 'type' if the category changed.
        */
        if ($this->isAttributeChanged('category_id'))
        {
            $category = $this->category ?? ContentCategory::findOne($this->category_id);
            
            if ($category !== null)
            {
                $this->type = $category->type;
            }
            else
            {
                $this->type = ContentCategory::TYPE_ITEM;
            }
        }
        
        // @url https://www.yiiframework.com/doc/api/2.0/yii-helpers-htmlpurifier
        $purifier = PurifierHelper::purifier();
        $this->title = $purifier->purify($this->title);
        $this->artist = $purifier->purify($this->artist);
        $this->dimensions = $purifier->purify($this->dimensions);
        $this->medium = $purifier->purify($this->medium);
        $this->year = $purifier->purify($this->year);
        $this->body = PurifierHelper::trumbowyg($this->body);
        $this->price = $purifier->purify($this->price);
        $this->quantity = $purifier->purify($this->quantity);
        $this->image_header = $purifier->purify($this->image_header);
        $this->product_image_one = $purifier->purify($this->product_image_one);
        $this->product_image_two = $purifier->purify($this->product_image_two);
        $this->product_image_three = $purifier->purify($this->product_image_three);
        $this->meta_description = $purifier->purify($this->meta_description);
        $this->meta_keywords = $purifier->purify($this->meta_keywords);
        
        return true;
    }
    
    /**
    * Get Allowed Templates by Type
    * @return array
    */
    public static function getAllowedTemplatesByType(): array
    {
        return self::$allowedTemplatesByType;
    }
    
    /**
    * Relations: category
    * @return ActiveQuery
    */
    public function getCategory(): ActiveQuery
    {
        return $this->hasOne(ContentCategory::class, ['id' => 'category_id']);
    }
    
    /**
    * Scope shortcuts for filtering by type
    */
    public static function findProducts(): ActiveQuery
    {
        return static::find()->andWhere(['type' => self::TYPE_PRODUCT]);
    }
    
    public static function findPosts(): ActiveQuery
    {
        return static::find()->andWhere(['type' => self::TYPE_POST]);
    }
}

Need to use Content template settings to give the option of what is avilable based on type, then we can set what templates are allowed and
save that within the category database and ill need to update my code for content after, but this should make the templating code easier.

Yes, your thinking is on the right track. Here's a concise plan and guidance on how to extend your current system to store allowed templates per category, dynamically enforce them, and keep templating code manageable:
1. Extend your ContentCategory model & DB:

    Add a new column to your content_category table, e.g.:
        allowed_templates of type TEXT or JSON.

    This stores the list of templates allowed for that category, e.g.:

["article", "exhibition", "catalog"]

Adjust your ContentCategory model:

    public function rules(): array
    {
        return array_merge(parent::rules(), [
            ['allowed_templates', 'safe'], // Make sure it passes validation safely
        ]);
    }

    public function getAllowedTemplates(): array
    {
        return json_decode($this->allowed_templates, true) ?: [];
    }

    In your admin form for categories, add a checkbox list for selecting allowed templates.

2. Modify your content (Content AR) template logic:

    Instead of solely relying on the global Content::$allowedTemplatesByType, fetch allowed templates from the ContentCategory of the content.

    Add method in Content:

    public function getAllowedTemplates(): array
    {
        if ($this->category && $this->category->allowed_templates) {
            return $this->category->getAllowedTemplates();
        }
        // fallback to type-based templates
        return self::$allowedTemplatesByType[$this->type] ?? [];
    }

    Adjust your form and frontend JS to use this method for populating templates dropdown dynamically from the current content’s category’s settings.

3. Validate the template against category allowed templates:

    Modify your validation method:

    public function validateTemplateByType($attribute, $params = []): void
    {
        if (!$this->type) {
            return;
        }

        $allowedTemplates = $this->getAllowedTemplates();

        if ($this->$attribute !== null && !in_array($this->$attribute, $allowedTemplates, true)) {
            $this->addError($attribute, \Yii::t('app',
                'The selected template "{template}" is not allowed for this category.',
                ['template' => $this->$attribute]));
        }
    }

4. Update your controller and form logic:

    Pass the content category’s allowed templates for the selected category to your view as JSON.
    Your JavaScript listens for category changes and updates the templates dropdown based on the category’s allowed templates instead of global type-based templates.

Benefits of this approach:

    More flexible per-category template control.
    Admins can customize allowed templates per category.
    Content creation respects category-level constraints automatically.
    Global type-based fallback remains as backup.

Summary
Step 	What to do
DB & Model 	Add allowed_templates field, interface to get them
Admin UI 	Add fields to manage allowed templates per category
Content AR Model 	Provide method to obtain allowed templates per category
Validation 	Validate template against category-specific allowed templates
Controller + Form + JS 	Change template dropdown options dynamically per category

If you want sample migration, form, and JS code snippets for this setup, just ask — I can prepare them!

i need the migration code to add a column into content_category

yes

Certainly! Here's an example Yii2 migration to add a JSON column named allowed_templates to the content_category table:

<?php

use yii\db\Migration;

/**
 * Handles adding allowed_templates to table `{{%content_category}}`.
 */
class mYYYYMMDD_HHMMSS_add_allowed_templates_to_content_category extends Migration
{
    /**
     * {@inheritdoc}
     */
    public function safeUp()
    {
        // Add `allowed_templates` column as JSON type if supported,
        // otherwise fallback to text with JSON encoded data
        if ($this->db->driverName === 'mysql') {
            $this->addColumn('{{%content_category}}', 'allowed_templates', $this->json()->null()->defaultValue(null));
        } else {
            // For databases without native JSON support, store as TEXT
            $this->addColumn('{{%content_category}}', 'allowed_templates', $this->text()->null());
        }
    }

    /**
     * {@inheritdoc}
     */
    public function safeDown()
    {
        $this->dropColumn('{{%content_category}}', 'allowed_templates');
    }
}

Notes

    Replace mYYYYMMDD_HHMMSS with the actual timestamp according to Yii2 conventions, e.g., m230612_101500.
    This migration tries to use native JSON column for MySQL; if you use PostgreSQL or others, adjust accordingly.
    If your DB does not support JSON, fallback to TEXT column storing JSON encoded string.

You can run this migration with:

yii migrate/create add_allowed_templates_to_content_category
yii migrate

If you want I can also help with:

    Model adjustments to use this column.
    Admin form for selecting templates.
    Handling JSON encoding/decoding automatically.

Just ask!

yes

Great! Here's a step-by-step example for the full workflow, starting with:
1. Migration to add allowed_templates column

<?php

use yii\db\Migration;

/**
 * Handles adding allowed_templates to table `{{%content_category}}`.
 */
class m230612_101500_add_allowed_templates_to_content_category extends Migration
{
    public function safeUp()
    {
        if ($this->db->driverName === 'mysql') {
            $this->addColumn('{{%content_category}}', 'allowed_templates', $this->json()->null()->defaultValue(null));
        } else {
            $this->addColumn('{{%content_category}}', 'allowed_templates', $this->text()->null());
        }
    }

    public function safeDown()
    {
        $this->dropColumn('{{%content_category}}', 'allowed_templates');
    }
}

Run:

yii migrate/create add_allowed_templates_to_content_category
yii migrate

2. Model updates in ContentCategory.php

Add attribute and helper methods:

class ContentCategory extends ActiveRecord
{
    // ... existing code ...

    public function rules(): array
    {
        return array_merge(parent::rules(), [
            ['allowed_templates', 'safe'],
        ]);
    }

    /**
     * Returns allowed templates for this category as array
     * @return array
     */
    public function getAllowedTemplates(): array
    {
        if (empty($this->allowed_templates)) {
            return [];
        }

        if (is_array($this->allowed_templates)) {
            return $this->allowed_templates; // already decoded
        }
        
        return json_decode($this->allowed_templates, true) ?: [];
    }

    public function setAllowedTemplates(array $templates): void
    {
        $this->allowed_templates = json_encode($templates);
    }
}

3. Admin form to edit allowed templates

In your category form view (e.g., _form.php for categories):

<?= $form->field($model, 'allowed_templates')->checkboxList([
    'article' => 'Article',
    'exhibition' => 'Exhibition',
    'artist' => 'Artist',
    'catalog' => 'Catalog',
    'item' => 'Item',
    'artwork' => 'Artwork',
    // add all your possible templates here
]) ?>

Make sure to load and save the JSON properly via getAllowedTemplates() and setAllowedTemplates().
4. Content form and controller adjustments

When loading the content creation/edit form:

    Load the category’s allowed templates dynamically.

Example (in controller):

$data = $this->getCategoryOptions(true);
$model->allowedTemplatesForCategory = [];

if ($model->category_id) {
    $category = ContentCategory::findOne($model->category_id);
    if ($category) {
        $model->allowedTemplatesForCategory = $category->getAllowedTemplates();
    }
}

// Pass $model->allowedTemplatesForCategory to view and JS for populating templates

In your JS and form, use the templates from the selected category instead of or in addition to the global allowedTemplatesByType.
5. Validation

Adjust your model validation to check if currently selected template is allowed for the category.

Example in Content model:

public function validateTemplateByCategory($attribute, $params)
{
    if (!$this->category) {
        return; // no category selected yet
    }

    $allowed = $this->category->getAllowedTemplates();

    if (!in_array($this->$attribute, $allowed, true)) {
        $this->addError($attribute, "The selected template '{$this->$attribute}' is not allowed for its category.");
    }
}

If you want, I can help you write complete sample controller and view code to glue this all together. Just let me know!

$this->text() going to stick with that instead of the json

Understood! Storing your allowed_templates as a TEXT column with JSON-encoded data is perfectly fine and widely used, especially if your DBMS doesn’t support native JSON columns or you want simplicity.
How to handle allowed_templates stored as JSON string in a TEXT column
Migration example (TEXT column):

public function safeUp()
{
    $this->addColumn('{{%content_category}}', 'allowed_templates', $this->text()->null());
}

public function safeDown()
{
    $this->dropColumn('{{%content_category}}', 'allowed_templates');
}

Model adjustments (ContentCategory):

public function getAllowedTemplates(): array
{
    if (empty($this->allowed_templates)) {
        return [];
    }

    // Decode JSON from TEXT column
    return json_decode($this->allowed_templates, true) ?: [];
}

public function setAllowedTemplates(array $templates): void
{
    $this->allowed_templates = json_encode($templates);
}

public function rules(): array
{
    return array_merge(parent::rules(), [
        ['allowed_templates', 'string'],
    ]);
}

Category admin form field example:

<?= $form->field($model, 'allowed_templates')->checkboxList([
    'article' => 'Article',
    'exhibition' => 'Exhibition',
    'artist' => 'Artist',
    'catalog' => 'Catalog',
    'item' => 'Item',
    'artwork' => 'Artwork',
    // ... your templates
], [
    'value' => $model->allowed_templates ? json_decode($model->allowed_templates, true) : [],
]) ?>

Make sure to override the form load/save behavior to handle JSON encoding/decoding properly if needed.
Summary:

    Use a TEXT column to store JSON-encoded allowed templates.
    Decode the JSON string on model access.
    Encode the array into JSON string on save.
    Use checkboxList in the admin UI to select allowed templates.
    Validate content templates against this JSON-based per-category allowed list.

If you’d like, I can help with the full example of Yii form model attribute setup to transparently encode/decode the JSON string for smooth usage.

```
<?= $form->field($model, 'allowed_templates')->checkboxList([
    'article' => 'Article',
    'exhibition' => 'Exhibition',
    'artist' => 'Artist',
    'catalog' => 'Catalog',
    'item' => 'Item',
    'artwork' => 'Artwork',
    // ... your templates
], [
    'value' => $model->allowed_templates ? json_decode($model->allowed_templates, true) : [],
]) ?>
```
is thier no way i can get that list instead of editing it all the time