# Nested Sets Behavior for Yii 2

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A modern nested sets behavior for the Yii framework utilizing the Modified Preorder Tree Traversal algorithm.

## Installation

The preferred way to install this extension is through [composer](http://getcomposer.org/download/).

Either run

```bash
$ php composer.phar require creocoder/yii2-nested-sets:dev-master
```

or add

```
"creocoder/yii2-nested-sets": "dev-master"
```

to the `require` section of your `composer.json` file.

## Configuring

First you need to configure model as follows:

```php
use creocoder\nestedsets\NestedSetsBehavior;

class Tree extends \yii\db\ActiveRecord
{
    public function behaviors() {
        return [
            NestedSetsBehavior::className(),
        ];
    }

    public function transactions()
    {
        return [
            self::SCENARIO_DEFAULT => self::OP_ALL,
        ];
    }

    public static function find()
    {
        return new TreeQuery(get_called_class());
    }
}
```

Second you need to configure query model as follows:

```php
use creocoder\nestedsets\NestedSetsQueryBehavior;

class TreeQuery extends \yii\db\ActiveQuery
{
    public function behaviors() {
        return [
            NestedSetsQueryBehavior::className(),
        ];
    }
}
```

## Usage

TBD.