npm package: @intocode-io/ts-nested-set
Description: Nested Set model implementation for Node.js written in TypeScript
Author: Satana Charuwichitratana
Latest version: 1.0.11

# Nested Set for Node.js written in TypeScript

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## Installation
```
npm install ts-nested-set
```

## Features
 * NestedSetNode instance has parent, children properties for ease of accessing the info
 * `append()` a node into existing node
 * `prepend()` a node into existing node
 * `flat()` into an array containing `{ left, right, depth, title }` information 
   for ease of updating to database later
 * `prevSibling()` retrieve the previous sibling or `null`
 * `nextSibling()` retrieve the next sibling or `null`
 * `isLeaf()` checks whether the node is the last node in the branch
 * `isRoot()` checks whether the node is the root node
 * `getSize()` get current node size. 2 if there is no children
 * `children` contains all children nodes. Empty array if the node has no child
 * `parent` refers to the parent node. `null` if the node is Root 

### Examples

#### Use NestedSetNode directly

```
import {NestedSetNode} from 'ts-nested-set';

let root = new NestedSetNode('Root'),
    nodeA = new NestedSetNode('Node A'),
    nodeB = new NestedSetNode('Node B', 0, 1, 1, root),
    nodeC = new NestedSetNode('Node C');

root.prepend(nodeA);
root.append(nodeC);

console.log('Root properties', root.toNestedSetProperties());
console.log('Node A properties', nodeA.toNestedSetProperties());
console.log('Node B properties', nodeB.toNestedSetProperties());
console.log('Node C properties', nodeC.toNestedSetProperties());

console.log('Flatten as an array', root.flat());
```

#### Extends NestedSetNode
```
import {NestedSetNode, NestedSetProperties} from 'ts-nested-set';

interface MenuProperties {
    menu_name: string;
    menu_lft: number;
    menu_rgt: number;
    menu_depth: number;
}

class NestedSetMenu extends NestedSetNode {

    static parseRow(props: NestedSetProperties): MenuProperties {
        return {
            menu_name: props.title,
            menu_lft: props.left,
            menu_rgt: props.right,
            menu_depth: props.depth
        };
    }

    constructor(menu_name: string) {
        super(menu_name);
    }

    public toRow(): MenuProperties {
        return NestedSetMenu.parseRow(this.toNestedSetProperties());
    }

    public toRows(): MenuProperties[] {
        let props: NestedSetProperties[] = super.flat(),
            rows: MenuProperties[];

        rows = props.map((row) => {
            return NestedSetMenu.parseRow(row);
        });

        return rows;
    }
}

let menuA = new NestedSetMenu('Menu A'),
    menuA1 = new NestedSetMenu('Menu A1');

menuA.append(menuA1);

console.log('Menu A', menuA.toRow());
console.log('Menu A flatten itself and all children to rows', menuA.toRows());
```

### License

Copyright &copy; 2017 Satana Charuwichitratana
Copyright &copy; 2018-2019 intocode Co., Ltd.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 
documentation files (the "Software"), to deal in the Software without restriction, including without limitation 
the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, 
and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions 
of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
THE USE OR OTHER DEALINGS IN THE SOFTWARE.