npm package: @odyzeo/form-item
Description: Odyzeo form item component with Vue
Author: Odyzeo
Latest version: 2.8.0

# @odyzeo/form-item

Simple input and textarea Vue.js component.

<a href="https://form-item.vercel.app/" target="_blank">Demo</a>

## Installation

### npm

```
npm install @odyzeo/form-item
```

Import and register component:
```
import FormItemPlugin, { FormErrors, FormItem, TextareaAutoresize }  from '@odyzeo/form-item';

Vue.use(FormItemPlugin, options);
// Vue.component('FormItem', FormItem); // Installed w/ FormItemPlugin
Vue.component('FormErrors', FormErrors);
Vue.directive('textarea-autoresize', TextareaAutoresize);
```

Import styles or make your own:
```
import '@odyzeo/form-item/dist/form-item.css';
```

## Usage

```vue
<template>
  <div>
      <form-item
        :input="simple"
        v-model="simple.value"
      ></form-item>
      
      <form-item
        :input="full"
        v-model="full.value"      
        :form-errors="formErrors.full"
        class="form-item--group"
        :bind-to-input="{ 'data-hj-whitelist': true }"
        :trans="toUpperCase"
        input-class="custom-class-for-input"
        group-name="form-item-form-test"
      >
        <template slot="prepend">
          <div class="form-item__readonly">Your</div>
        </template>
        <template slot="append">
          <div class="form-item__readonly">Please</div>
        </template>
      </form-item>

      <form-item
          :ref="textarea.name"
          v-model="textarea.value"
          v-textarea-autoresize:window="{ max: 200 }"
          :input="textarea"
          :trans="customTranslate"
      ></form-item>

      <form-errors
          :form-errors="formErrors"
      ></form-errors>
  </div>
</template>
```

```vue
<script>
import FormItem from '@odyzeo/form-item'

export default {
    name: 'App',
    components: {
        FormItem,
    },
    data() {
        return {
            simple: {
                label: 'Simple',
                value: '',
            },
            full: {
                type: 'email',
                name: 'email',
                required: true,
                readonly: false,
                placeholder: 'example@odyzeo.com',
                accept: '', // Just for input type 'file'
                validators: [
                    {
                        validator: 'email',
                    },
                    {
                        validator: 'required',
                        message: 'Povinné',
                    },
                ],
                rows: 0, // Just for input type 'textarea'
                autocomplete: 'username email',
                label: 'E-mail',
                value: '',
            },
            requiredMessage: 'Povinné',
            formErrors: {
                email: ['E-mail is required'],
            },
            textarea: {
                name: 'textarea',
                type: 'textarea',
                label: 'Textarea',
                placeholder: 'Textarea placeholder',
                rows: 3,
                value: 'Some text just for textarea',
            },
        };
    },
    methods: {
        toUpperCase(key) {
            return key.toUpperCase();
        },
    },
};
</script>
```

## Plugin options
| Property name  | Type     | Default value  | Description                                              |
| -------------- | -------- | -------------- | -------------------------------------------------------- |
| `className`    | String   | 'form-item'    | Set component block className (set B in BEM)             |
| `componentName`| String   | 'form-item'    | Set component name                                       |
| `trans`        | function | `(key) => key` | Enable translating or modifying labels and placeholders. |

### Example using vui-i18n
```javascript
import Vue from 'vue';
import VueI18n from 'vue-i18n';
import App from './App';
import FormItem from './plugin/FormItem';

Vue.use(VueI18n);

new Vue({
    i18n,
    render: h => h(App),
    created() {
        Vue.use(FormItem, {
            trans: this.$t,
        });
    }
}).$mount('#app');
```

## Props

### input {Object} -  required
| Property name | Type | Default value | Description |
| ------------- | ---- | ------------- | ----------- |
| `type` | string | `text` | Supports 'textarea' and [all](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input) html5 input types supports |
| `name` | string | `` | Textarea or input `name` attribute |
| `label` | string | `''` | Label name for input |
| `required` | boolean | `false` | If value is required |
| `disabled` | boolean | `false` | Set input to disabled state, validator would skip this field |
| `readonly` | boolean | `false` | If field is read only |
| `placeholder` | string | `` | Native placeholder attribute for input/textarea |
| `accept` | string |  | Which file types should be accepted if type is file |
| `validators` | array | `null` | Array holding objects with `validator {string} - name of validator` and `message {string} - error message text` properties |
| `validatorEvent` | string | `none` | Pick validator events which will be used for frontend validation. Choose from: <ul><li>`onBlurThenOnInput`: validate field on blur first, then on input periodically</li> <li>`onBlur`</li> <li>`onInput`</li></ul>|
| `rows` | number, string | `` | Number of rows textarea should have |
| `autocomplete` | string | `off` | HTML5 autocomplete attribute, check [docs](https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/autocomplete) for more info and possible values |
| `pattern` | string | `` | Pattern attribute specifies a regular expression that the <input> element's value is checked against on form submission |
| `id` | string | `` | Id for input or textarea and for respective label |

### className {string = ''} - optional 
Set component block className (set B in BEM), has priority over `className` option in plugin.

### groupName {string = ''} - optional 
Set if you need to target one or more form item components with global methods

### value {string} - optional
This is the initial value of the form input/textarea. Use `v-model` for reactivity.

### trans {Function} - optional 
Custom function to translate or modify input placeholder and label.

### formErrors {array} - optional
Array of errors to display. Will take priority before FE validator errors until value is changed.

## Available validators
- `email`
- `zip`
- `tel` : phone number
- `max` : length of string - Use `$0` in validator `message` to replace number.
- `min` : length of string - Use `$0` in validator `message` to replace number.
- `confirmed `: confirmed passwords
- `regex` : your custom regex
- `required` : for custom required message

## Custom validator
It is possible to use your own validator instead of predefined one.

The custom validator has to be a valid return function with value parameter.
You can also make use of a custom message property as per predefined validators.

```vue
validators: {
    validator: value => value.indexOf(`joseph`) !== -1,
    message: 'My custom error message',
}
``` 

### Custom validator with parameters
If your validator needs to provide parameters, you can simply create a higher order 
function that returns the actual validator, like in between builtin validator.  

```vue
const myFunc = param => value => value.indexOf(`${param} joseph`) !== -1;

// ...

validators: {
    validator: myFunc('some text'),
    message: 'My custom error message',
}

```

### bindToInput {Object} - optional
Used for generating custom attributes to input/textarea element.

### inputClass {string} - optional
Used for adding custom class to input/textarea element.

## Global methods
Methods called on `$formItem` object installed on main Vue instance

### $formItem.validate(name)
- Arguments:
    - `{string} name` Group name of one or multiple form items
    
- Usage: 

    Trigger validation of all form items corresponding to group name argument
   
### $formItem.clear(name)
- Arguments:
    - `{string} name` Group name of one or multiple form items
   
- Usage: 

    Clear inputs and errors on all form items corresponding to group name argument

### $formItem.getErrors(name)
- Arguments:
    - `{string} name` Group name of one or multiple form items
   
- Returns: 
    - Array of errors
   
- Usage: 

    Get all current FE errors of all form items corresponding to group name argument 

### $formItem.hasErrors(name)
- Arguments:
    - `{string} name` Group name of one or multiple form items
   
- Returns: 
    - Boolean indicating whether group of items got errors

## Events
Component emits these events:
- `@blur`
- `@eager` - Emits event on 'input' event (get value from `event.currentTarget.value`)
- `@focus`
- `@input` - Emits the value of the element (not working w/ suggestions)
- `@keydown`
- `@keyup`

## Development

```
npm run serve
```