First commit

9 years ago · 7f8633ea98
8 changed files with 1030 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@ -0,0 +1,15 @@
+# phpstorm project files
+.idea
+
+# windows thumbnail cache
+Thumbs.db
+
+# composer vendor dir
+/vendor
+
+# composer itself is not needed
+composer.phar
+composer.lock
+
+# Mac DS_Store Files
+.DS_Store
--- a/22
+++ b/22
@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 PaulZi (pavel.zimakoff@gmail.com)
+
+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.
+
--- a/NestedSetsBehavior.php
+++ b/NestedSetsBehavior.php
@ -0,0 +1,648 @@
+<?php
+/**
+ * @link https://github.com/paulzi/yii2-nested-sets
+ * @copyright Copyright (c) 2015 PaulZi <pavel.zimakoff@gmail.com>
+ * @license MIT (https://github.com/paulzi/yii2-nested-sets/blob/master/LICENSE)
+ */
+
+namespace paulzi\nestedsets;
+
+use Yii;
+use yii\base\Behavior;
+use yii\base\Exception;
+use yii\base\NotSupportedException;
+use yii\db\ActiveRecord;
+use yii\db\Expression;
+
+/**
+ * Nested Sets Behavior for Yii2
+ * @author PaulZi <pavel.zimakoff@gmail.com>
+ * @author Alexander Kochetov <https://github.com/creocoder>
+ *
+ * @property ActiveRecord $owner
+ */
+class NestedSetsBehavior extends Behavior
+{
+    const OPERATION_MAKE_ROOT       = 1;
+    const OPERATION_PREPEND_TO      = 2;
+    const OPERATION_APPEND_TO       = 3;
+    const OPERATION_INSERT_BEFORE   = 4;
+    const OPERATION_INSERT_AFTER    = 5;
+    const OPERATION_DELETE_ALL      = 6;
+
+
+    /**
+     * @var string|null
+     */
+    public $treeAttribute;
+
+    /**
+     * @var string
+     */
+    public $leftAttribute = 'lft';
+
+    /**
+     * @var string
+     */
+    public $rightAttribute = 'rgt';
+
+    /**
+     * @var string
+     */
+    public $depthAttribute = 'depth';
+
+    /**
+     * @var string|null
+     */
+    protected $operation;
+
+    /**
+     * @var ActiveRecord|self|null
+     */
+    protected $node;
+
+
+    /**
+     * @inheritdoc
+     */
+    public function events()
+    {
+        return [
+            ActiveRecord::EVENT_BEFORE_INSERT   => 'beforeInsert',
+            ActiveRecord::EVENT_AFTER_INSERT    => 'afterInsert',
+            ActiveRecord::EVENT_BEFORE_UPDATE   => 'beforeUpdate',
+            ActiveRecord::EVENT_AFTER_UPDATE    => 'afterUpdate',
+            ActiveRecord::EVENT_BEFORE_DELETE   => 'beforeDelete',
+            ActiveRecord::EVENT_AFTER_DELETE    => 'afterDelete',
+        ];
+    }
+
+    /**
+     * @param int|null $depth
+     * @return \yii\db\ActiveQuery
+     */
+    public function getParents($depth = null)
+    {
+        $tableName = $this->owner->tableName();
+        $condition = [
+            'and',
+            ['<', "{$tableName}.[[{$this->leftAttribute}]]",  $this->owner->getAttribute($this->leftAttribute)],
+            ['>', "{$tableName}.[[{$this->rightAttribute}]]", $this->owner->getAttribute($this->rightAttribute)],
+        ];
+        if ($depth !== null) {
+            $condition[] = ['>=', "{$tableName}.[[{$this->depthAttribute}]]", $this->owner->getAttribute($this->depthAttribute) - $depth];
+        }
+
+        $query = $this->owner->find()
+            ->andWhere($condition)
+            ->andWhere($this->treeCondition())
+            ->addOrderBy(["{$tableName}.[[{$this->leftAttribute}]]" => SORT_ASC]);
+        $query->multiple = true;
+
+        return $query;
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getParent()
+    {
+        $tableName = $this->owner->tableName();
+        $query = $this->getParents(1)
+            ->orderBy(["{$tableName}.[[{$this->leftAttribute}]]" => SORT_DESC])
+            ->limit(1);
+        $query->multiple = false;
+        return $query;
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getRoot()
+    {
+        $tableName = $this->owner->tableName();
+        $query = $this->owner->find()
+            ->andWhere(["{$tableName}.[[{$this->leftAttribute}]]" => 1])
+            ->andWhere($this->treeCondition())
+            ->limit(1);
+        $query->multiple = false;
+        return $query;
+    }
+
+    /**
+     * @param int|null $depth
+     * @param bool $andSelf
+     * @param bool $backOrder
+     * @return \yii\db\ActiveQuery
+     */
+    public function getDescendants($depth = null, $andSelf = false, $backOrder = false)
+    {
+        $tableName = $this->owner->tableName();
+        $attribute = $backOrder ? $this->rightAttribute : $this->leftAttribute;
+        $condition = [
+            'and',
+            [$andSelf ? '>=' : '>', "{$tableName}.[[{$attribute}]]",  $this->owner->getAttribute($this->leftAttribute)],
+            [$andSelf ? '<=' : '<', "{$tableName}.[[{$attribute}]]",  $this->owner->getAttribute($this->rightAttribute)],
+        ];
+
+        if ($depth !== null) {
+            $condition[] = ['<=', "{$tableName}.[[{$this->depthAttribute}]]", $this->owner->getAttribute($this->depthAttribute) + $depth];
+        }
+
+        $query = $this->owner->find()
+            ->andWhere($condition)
+            ->andWhere($this->treeCondition())
+            ->addOrderBy(["{$tableName}.[[{$attribute}]]" => $backOrder ? SORT_DESC : SORT_ASC]);
+        $query->multiple = true;
+
+        return $query;
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getChildren()
+    {
+        return $this->getDescendants(1);
+    }
+
+    /**
+     * @param int|null $depth
+     * @return \yii\db\ActiveQuery
+     */
+    public function getLeaves($depth = null)
+    {
+        $tableName = $this->owner->tableName();
+        $query = $this->getDescendants($depth)
+            ->andWhere(["{$tableName}.[[{$this->leftAttribute}]]" => new Expression("{$tableName}.[[{$this->rightAttribute}]] - 1")]);
+        $query->multiple = true;
+        return $query;
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getPrev()
+    {
+        $tableName = $this->owner->tableName();
+        $query = $this->owner->find()
+            ->andWhere(["{$tableName}.[[{$this->rightAttribute}]]" => $this->owner->getAttribute($this->leftAttribute) - 1])
+            ->andWhere($this->treeCondition())
+            ->limit(1);
+        $query->multiple = false;
+        return $query;
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getNext()
+    {
+        $tableName = $this->owner->tableName();
+        $query = $this->owner->find()
+            ->andWhere(["{$tableName}.[[{$this->leftAttribute}]]" => $this->owner->getAttribute($this->rightAttribute) + 1])
+            ->andWhere($this->treeCondition())
+            ->limit(1);
+        $query->multiple = false;
+        return $query;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isRoot()
+    {
+        return $this->owner->getAttribute($this->leftAttribute) === 1;
+    }
+
+    /**
+     * @param ActiveRecord $node
+     * @return bool
+     */
+    public function isChildOf($node)
+    {
+        $result = $this->owner->getAttribute($this->leftAttribute) > $node->getAttribute($this->leftAttribute)
+            && $this->owner->getAttribute($this->rightAttribute) < $node->getAttribute($this->rightAttribute);
+
+        if ($result && $this->treeAttribute !== null) {
+            $result = $this->owner->getAttribute($this->treeAttribute) === $node->getAttribute($this->treeAttribute);
+        }
+
+        return $result;
+    }
+
+    /**
+     * @return bool
+     */
+    public function isLeaf()
+    {
+        return $this->owner->getAttribute($this->rightAttribute) - $this->owner->getAttribute($this->leftAttribute) === 1;
+    }
+
+    /**
+     * @return ActiveRecord
+     */
+    public function makeRoot()
+    {
+        $this->operation = self::OPERATION_MAKE_ROOT;
+        return $this->owner;
+    }
+
+    /**
+     * @param ActiveRecord $node
+     * @return ActiveRecord
+     */
+    public function prependTo($node)
+    {
+        $this->operation = self::OPERATION_PREPEND_TO;
+        $this->node = $node;
+        return $this->owner;
+    }
+
+    /**
+     * @param ActiveRecord $node
+     * @return ActiveRecord
+     */
+    public function appendTo($node)
+    {
+        $this->operation = self::OPERATION_APPEND_TO;
+        $this->node = $node;
+        return $this->owner;
+    }
+
+    /**
+     * @param ActiveRecord $node
+     * @return ActiveRecord
+     */
+    public function insertBefore($node)
+    {
+        $this->operation = self::OPERATION_INSERT_BEFORE;
+        $this->node = $node;
+        return $this->owner;
+    }
+
+    /**
+     * @param ActiveRecord $node
+     * @return ActiveRecord
+     */
+    public function insertAfter($node)
+    {
+        $this->operation = self::OPERATION_INSERT_AFTER;
+        $this->node = $node;
+        return $this->owner;
+    }
+
+    /**
+     * @return bool|int
+     * @throws \Exception
+     * @throws \yii\db\Exception
+     */
+    public function deleteWithChildren()
+    {
+        $this->operation = self::OPERATION_DELETE_ALL;
+        if (!$this->owner->isTransactional(ActiveRecord::OP_DELETE)) {
+            $transaction = $this->owner->getDb()->beginTransaction();
+            try {
+                $result = $this->deleteWithChildrenInternal();
+                if ($result === false) {
+                    $transaction->rollBack();
+                } else {
+                    $transaction->commit();
+                }
+                return $result;
+            } catch (\Exception $e) {
+                $transaction->rollBack();
+                throw $e;
+            }
+        } else {
+            $result = $this->deleteWithChildrenInternal();
+        }
+        return $result;
+    }
+
+    /**
+     * @throws Exception
+     * @throws NotSupportedException
+     */
+    public function beforeInsert()
+    {
+        if ($this->node !== null && !$this->node->getIsNewRecord()) {
+            $this->node->refresh();
+        }
+        switch ($this->operation) {
+            case self::OPERATION_MAKE_ROOT:
+                $condition = array_merge([$this->leftAttribute => 1], $this->treeCondition());
+                if ($this->owner->findOne($condition) !== null) {
+                    throw new Exception('Can not create more than one root.');
+                }
+                $this->owner->setAttribute($this->leftAttribute,  1);
+                $this->owner->setAttribute($this->rightAttribute, 2);
+                $this->owner->setAttribute($this->depthAttribute, 0);
+                break;
+
+            case self::OPERATION_PREPEND_TO:
+                $this->insertNode($this->node->getAttribute($this->leftAttribute) + 1, 1);
+                break;
+
+            case self::OPERATION_APPEND_TO:
+                $this->insertNode($this->node->getAttribute($this->rightAttribute), 1);
+                break;
+
+            case self::OPERATION_INSERT_BEFORE:
+                $this->insertNode($this->node->getAttribute($this->leftAttribute), 0);
+                break;
+
+            case self::OPERATION_INSERT_AFTER:
+                $this->insertNode($this->node->getAttribute($this->rightAttribute) + 1, 0);
+                break;
+
+            default:
+                throw new NotSupportedException('Method "'. $this->owner->className() . '::insert" is not supported for inserting new nodes.');
+        }
+    }
+
+    /**
+     * @throws Exception
+     */
+    public function afterInsert()
+    {
+        if ($this->operation === self::OPERATION_MAKE_ROOT && $this->treeAttribute !== null && $this->owner->getAttribute($this->treeAttribute) === null) {
+            $id = $this->owner->getPrimaryKey();
+            $this->owner->setAttribute($this->treeAttribute, $id);
+
+            $primaryKey = $this->owner->primaryKey();
+            if (!isset($primaryKey[0])) {
+                throw new Exception('"' . $this->owner->className() . '" must have a primary key.');
+            }
+
+            $this->owner->updateAll([$this->treeAttribute => $id], [$primaryKey[0] => $id]);
+        }
+        $this->operation = null;
+        $this->node      = null;
+    }
+
+    /**
+     * @throws Exception
+     */
+    public function beforeUpdate()
+    {
+        if ($this->node !== null && !$this->node->getIsNewRecord()) {
+            $this->node->refresh();
+        }
+
+        switch ($this->operation) {
+            case self::OPERATION_MAKE_ROOT:
+                if ($this->treeAttribute === null) {
+                    throw new Exception('Can not move a node as the root when "treeAttribute" is not set.');
+                }
+                if ($this->isRoot()) {
+                    throw new Exception('Can not move the root node as the root.');
+                }
+                break;
+
+            case self::OPERATION_INSERT_BEFORE:
+            case self::OPERATION_INSERT_AFTER:
+                if ($this->node->isRoot()) {
+                    throw new Exception('Can not move a node before/after root.');
+                }
+
+            case self::OPERATION_PREPEND_TO:
+            case self::OPERATION_APPEND_TO:
+                if ($this->node->getIsNewRecord()) {
+                    throw new Exception('Can not move a node when the target node is new record.');
+                }
+
+                if ($this->owner->equals($this->node)) {
+                    throw new Exception('Can not move a node when the target node is same.');
+                }
+
+                if ($this->node->isChildOf($this->owner)) {
+                    throw new Exception('Can not move a node when the target node is child.');
+                }
+        }
+    }
+
+    /**
+     *
+     */
+    public function afterUpdate()
+    {
+        switch ($this->operation) {
+            case self::OPERATION_MAKE_ROOT:
+                $this->moveNodeAsRoot();
+                break;
+
+            case self::OPERATION_PREPEND_TO:
+                $this->moveNode($this->node->getAttribute($this->leftAttribute) + 1, 1);
+                break;
+
+            case self::OPERATION_APPEND_TO:
+                $this->moveNode($this->node->getAttribute($this->rightAttribute), 1);
+                break;
+
+            case self::OPERATION_INSERT_BEFORE:
+                $this->moveNode($this->node->getAttribute($this->leftAttribute), 0);
+                break;
+
+            case self::OPERATION_INSERT_AFTER:
+                $this->moveNode($this->node->getAttribute($this->rightAttribute) + 1, 0);
+                break;
+        }
+        $this->operation = null;
+        $this->node      = null;
+    }
+
+    /**
+     * @throws Exception
+     */
+    public function beforeDelete()
+    {
+        if ($this->owner->getIsNewRecord()) {
+            throw new Exception('Can not delete a node when it is new record.');
+        }
+        if ($this->isRoot() && $this->operation !== self::OPERATION_DELETE_ALL) {
+            throw new Exception('Method "'. $this->owner->className() . '::delete" is not supported for deleting root nodes.');
+        }
+        $this->owner->refresh();
+    }
+
+    /**
+     *
+     */
+    public function afterDelete()
+    {
+        $left  = $this->owner->getAttribute($this->leftAttribute);
+        $right = $this->owner->getAttribute($this->rightAttribute);
+        if ($this->operation === static::OPERATION_DELETE_ALL || $this->isLeaf()) {
+            $this->shift($right + 1, null, $left - $right - 1);
+        } else {
+            $this->owner->updateAll(
+                [
+                    $this->leftAttribute  => new Expression("[[{$this->leftAttribute}]] - 1"),
+                    $this->rightAttribute => new Expression("[[{$this->rightAttribute}]] - 1"),
+                    $this->depthAttribute => new Expression("[[{$this->depthAttribute}]] - 1"),
+                ],
+                $this->getDescendants()->where
+            );
+            $this->shift($right + 1, null, -2);
+        }
+        $this->operation = null;
+        $this->node      = null;
+    }
+
+    /**
+     * @return int
+     */
+    protected function deleteWithChildrenInternal()
+    {
+        if (!$this->owner->beforeDelete()) {
+            return false;
+        }
+        $result = $this->owner->deleteAll($this->getDescendants(null, true)->where);
+        $this->owner->setOldAttributes(null);
+        $this->owner->afterDelete();
+        return $result;
+    }
+
+    /**
+     * @param int $to
+     * @param int $depth
+     * @throws Exception
+     */
+    protected function insertNode($to, $depth = 0)
+    {
+        if ($this->node->getIsNewRecord()) {
+            throw new Exception('Can not create a node when the target node is new record.');
+        }
+
+        if ($depth === 0 && $this->node->isRoot()) {
+            throw new Exception('Can not insert a node before/after root.');
+        }
+        $this->owner->setAttribute($this->leftAttribute,  $to);
+        $this->owner->setAttribute($this->rightAttribute, $to + 1);
+        $this->owner->setAttribute($this->depthAttribute, $this->node->getAttribute($this->depthAttribute) + $depth);
+        if ($this->treeAttribute !== null) {
+            $this->owner->setAttribute($this->treeAttribute, $this->node->getAttribute($this->treeAttribute));
+        }
+        $this->shift($to, null, 2);
+    }
+
+    /**
+     * @param int $to
+     * @param int $depth
+     * @throws Exception
+     */
+    protected function moveNode($to, $depth = 0)
+    {
+        $left  = $this->owner->getAttribute($this->leftAttribute);
+        $right = $this->owner->getAttribute($this->rightAttribute);
+        $depth = $this->owner->getAttribute($this->depthAttribute) - $this->node->getAttribute($this->depthAttribute) - $depth;
+        if ($this->treeAttribute === null || $this->owner->getAttribute($this->treeAttribute) === $this->node->getAttribute($this->treeAttribute)) {
+            // same root
+            $this->owner->updateAll(
+                [$this->depthAttribute => new Expression("-[[{$this->depthAttribute}]]" . sprintf('%+d', $depth))],
+                $this->getDescendants(null, true)->where
+            );
+            $delta = $right - $left + 1;
+            if ($left >= $to) {
+                $this->shift($to, $left - 1, $delta);
+                $delta = $to - $left;
+            } else {
+                $this->shift($right + 1, $to, -$delta);
+                $delta = $to - $right;
+            }
+            $this->owner->updateAll(
+                [
+                    $this->leftAttribute  => new Expression("[[{$this->leftAttribute}]]"  . sprintf('%+d', $delta)),
+                    $this->rightAttribute => new Expression("[[{$this->rightAttribute}]]" . sprintf('%+d', $delta)),
+                    $this->depthAttribute => new Expression("-[[{$this->depthAttribute}]]"),
+                ],
+                [
+                    'and',
+                    $this->getDescendants(null, true)->where,
+                    ['<', $this->depthAttribute, 0],
+                ]
+            );
+        } else {
+            // move from other root
+            $tree = $this->node->getAttribute($this->treeAttribute);
+            $this->shift($to, null, $right - $left + 1, $tree);
+            $delta = $to - $left;
+            $this->owner->updateAll(
+                [
+                    $this->leftAttribute  => new Expression("[[{$this->leftAttribute}]]"  . sprintf('%+d', $delta)),
+                    $this->rightAttribute => new Expression("[[{$this->rightAttribute}]]" . sprintf('%+d', $delta)),
+                    $this->depthAttribute => new Expression("[[{$this->depthAttribute}]]" . sprintf('%+d', -$depth)),
+                    $this->treeAttribute  => $tree,
+                ],
+                $this->getDescendants(null, true)->where
+            );
+            $this->shift($right + 1, null, $left - $right - 1);
+        }
+    }
+
+    /**
+     *
+     */
+    protected function moveNodeAsRoot()
+    {
+        $left   = $this->owner->getAttribute($this->leftAttribute);
+        $right  = $this->owner->getAttribute($this->rightAttribute);
+        $depth  = $this->owner->getAttribute($this->depthAttribute);
+        $tree   = $this->owner->getPrimaryKey();
+        if ($this->owner->getOldAttribute($this->treeAttribute) !== $this->owner->getAttribute($this->treeAttribute)) {
+            $tree = $this->owner->getAttribute($this->treeAttribute);
+        }
+
+        $this->owner->updateAll(
+            [
+                $this->leftAttribute  => new Expression("[[{$this->leftAttribute}]]"  . sprintf('%+d', 1 - $left)),
+                $this->rightAttribute => new Expression("[[{$this->rightAttribute}]]" . sprintf('%+d', 1 - $left)),
+                $this->depthAttribute => new Expression("[[{$this->depthAttribute}]]" . sprintf('%+d', -$depth)),
+                $this->treeAttribute  => $tree,
+            ],
+            $this->getDescendants(null, true)->where
+        );
+        $this->shift($right + 1, null, $left - $right - 1);
+    }
+
+
+
+    /**
+     * @param int $from
+     * @param int $to
+     * @param int $delta
+     * @param int|null $tree
+     */
+    protected function shift($from, $to, $delta, $tree = null)
+    {
+        if ($delta !== 0 && ($to === null || $to >= $from)) {
+            if ($tree === null) {
+                $tree = $this->owner->getAttribute($this->treeAttribute);
+            }
+            foreach ([$this->leftAttribute, $this->rightAttribute] as $i => $attribute) {
+                $this->owner->updateAll(
+                    [$attribute => new Expression("[[{$attribute}]]" . sprintf('%+d', $delta))],
+                    [
+                        'and',
+                        $to === null ? ['>=', $attribute, $from] : ['between', $attribute, $from, $to],
+                        [$this->treeAttribute => $tree],
+                    ]
+                );
+            }
+        }
+    }
+
+    /**
+     * @return array
+     */
+    protected function treeCondition()
+    {
+        $tableName = $this->owner->tableName();
+        if ($this->treeAttribute === null) {
+            return [];
+        } else {
+            return ["{$tableName}.[[{$this->treeAttribute}]]" => $this->owner->getAttribute($this->treeAttribute)];
+        }
+    }
+}
--- a/NestedSetsQueryTrait.php
+++ b/NestedSetsQueryTrait.php
@ -0,0 +1,30 @@
+<?php
+/**
+ * @link https://github.com/paulzi/yii2-nested-sets
+ * @copyright Copyright (c) 2015 PaulZi <pavel.zimakoff@gmail.com>
+ * @license MIT (https://github.com/paulzi/yii2-nested-sets/blob/master/LICENSE)
+ */
+
+namespace paulzi\nestedsets;
+
+/**
+ * @author PaulZi <pavel.zimakoff@gmail.com>
+ */
+trait NestedSetsQueryTrait
+{
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function roots()
+    {
+        /** @var \yii\db\ActiveQuery $this */
+        $class = $this->modelClass;
+        if (isset($class::$nestedSetsLeftAttribute)) {
+            return $this->andWhere([$class::$nestedSetsLeftAttribute => 1]);
+        } else {
+            /** @var \yii\db\ActiveRecord|NestedSetsBehavior $model */
+            $model = new $class;
+            return $this->andWhere([$model->leftAttribute => 1]);
+        }
+    }
+}
--- a/README.md
+++ b/README.md
@ -0,0 +1,233 @@
+# Yii2 Nested Sets Behavior
+
+Implementation of nested sets algorithm for storing the trees in DB tables.  
+
+## Install
+
+Install via Composer:
+
+```bash
+composer require paulzi/yii2-nested-sets
+```
+
+or add
+
+```bash
+"paulzi/yii2-nested-sets" : "^1.0"
+```
+
+to the `require` section of your `composer.json` file.
+
+## Migrations
+
+Sample migrations are in the folder `sample-migrations`:
+
+- `m150722_150000_single_tree.php` - for single tree tables;
+- `m150722_150100_multiple_tree.php` - for multiple tree tables.
+
+## Configuring
+
+```php
+use paulzi\nestedsets\NestedSetsBehavior;
+
+class Sample extends \yii\db\ActiveRecord
+{
+    public function behaviors() {
+        return [
+            [
+                'class' => NestedSetsBehavior::className(),
+                // 'treeAttribute' => 'tree',
+            ],
+        ];
+    }
+
+    public function transactions()
+    {
+        return [
+            self::SCENARIO_DEFAULT => self::OP_ALL,
+        ];
+    }
+}
+```
+
+Optional you can setup Query for finding roots:
+
+```php
+class Sample extends \yii\db\ActiveRecord
+{
+    public static function find()
+    {
+        return new SampleQuery(get_called_class());
+    }
+}
+```
+
+Query class:
+
+```php
+use paulzi\nestedsets\NestedSetsQueryTrait;
+
+class SampleQuery extends \yii\db\ActiveQuery
+{
+    use NestedSetsQueryTrait;
+}
+```
+
+## Options
+
+- `$treeAttribute = null` - setup tree attribute for multiple tree in table schema.
+- `$leftAttribute = 'lft'` - left attribute in table schema.
+- `$rightAttribute = 'rgt'` - right attribute in table schema.
+- `$depthAttribute = 'depth'` - depth attribute in table schema (note: it must be signed int).
+
+## Usage
+
+### Selection
+
+**Getting the root nodes**
+
+If you connect `NestedSetsQueryTrait`, you can get all the root nodes:
+
+```php
+$roots = Sample::find()->roots()->all();
+```
+
+**Getting ancestors of a node**
+
+To get ancestors of a node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$parents = $node11->parents; // via relation
+$parents = $node11->getParents()->all(); // via query
+$parents = $node11->getParents(2)->all(); // get 2 levels of ancestors
+```
+
+To get parent of a node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$parent = $node11->parent; // via relation
+$parent = $node11->getParent()->one(); // via query
+```
+
+To get root of a node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$root = $node11->root; // via relation
+$root = $node11->getRoot()->one(); // via query
+```
+
+**Getting descendants of a node**
+
+To get all the descendants of a node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$descendants = $node11->descendants; // via relation
+$descendants = $node11->getDescendants()->all(); // via query
+$descendants = $node11->getDescendants(2, true)->all(); // get 2 levels of descendants and self node
+$descendants = $node11->getDescendants(3, false, true)->all(); // get 3 levels of descendants in back order
+```
+
+To get the children of a node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$children = $node11->children; // via relation
+$children = $node11->getChildren()->all(); // via query
+```
+
+**Getting the leaves nodes**
+
+To get all the leaves of a node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$leaves = $node11->leaves; // via relation
+$leaves = $node11->getLeaves(2)->all(); // get 2 levels of leaves via query
+```
+
+**Getting the neighbors nodes**
+
+To get the next node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$next = $node11->next; // via relation
+$next = $node11->getNext()->one(); // via query
+```
+
+To get the previous node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$prev = $node11->prev; // via relation
+$prev = $node11->getPrev()->one(); // via query
+```
+
+### Some checks
+
+```php
+$node1 = Sample::findOne(['name' => 'node 1']);
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$node11->isRoot() - return true, if node is root
+$node11->isLeaf() - return true, if node is leaf
+$node11->isChildOf($node1) - return true, if node11 is child of $node1
+```
+
+
+### Modifications
+
+To make a root node:
+
+```php
+$node11 = new Sample();
+$node11->name = 'node 1.1';
+$node11->makeRoot()->save();
+```
+
+*Note: if you allow multiple trees and attribute `tree` is not set, it automatically takes the primary key value.*
+
+To prepend a node as the first child of another node:
+
+```php
+$node1 = Sample::findOne(['name' => 'node 1']);
+$node11 = new Sample();
+$node11->name = 'node 1.1';
+$node11->prependTo($node1)->save(); // inserting new node
+```
+
+To append a node as the last child of another node:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$node12 = Sample::findOne(['name' => 'node 1.2']);
+$node12->appendTo($node11)->save(); // move existing node
+```
+
+To insert a node before another node:
+
+```php
+$node13 = Sample::findOne(['name' => 'node 1.3']);
+$node12 = new Sample();
+$node12->name = 'node 1.2';
+$node12->insertBefore($node13)->save(); // inserting new node
+```
+
+To insert a node after another node:
+
+```php
+$node13 = Sample::findOne(['name' => 'node 1.3']);
+$node14 = Sample::findOne(['name' => 'node 1.4']);
+$node14->insertAfter($node13)->save(); // move existing node
+```
+
+To delete a node with descendants:
+
+```php
+$node11 = Sample::findOne(['name' => 'node 1.1']);
+$node11->delete(); // delete node, children come up to the parent
+$node11->deleteWithChildren(); // delete node and all descendants 
+```
--- a/composer.json
+++ b/composer.json
@ -0,0 +1,31 @@
+{
+  "name": "paulzi/yii2-nested-sets",
+  "description": "Nested Sets Behavior for Yii2",
+  "keywords": ["yii2", "nested sets"],
+  "type": "yii2-extension",
+  "license": "MIT",
+  "support": {
+    "issues": "https://github.com/paulzi/yii2-nested-sets/issues?state=open",
+    "source": "https://github.com/paulzi/yii2-nested-sets"
+  },
+  "authors": [
+    {
+      "name": "PaulZi",
+      "email": "pavel.zimakoff@gmail.com"
+    },
+    {
+      "name": "Alexander Kochetov",
+      "email": "creocoder@gmail.com"
+    }
+  ],
+  "minimum-stability": "stable",
+  "require": {
+    "php": ">=5.4.0",
+    "yiisoft/yii2": "~2.0.0"
+  },
+  "autoload": {
+    "psr-4": {
+      "paulzi\\nestedsets\\": ""
+    }
+  }
+}
--- a/sample-migrations/m150722_150000_single_tree.php
+++ b/sample-migrations/m150722_150000_single_tree.php
@ -0,0 +1,25 @@
+<?php
+
+use yii\db\Schema;
+use yii\db\Migration;
+
+class m150722_150000_single_tree extends Migration
+{
+    public function up()
+    {
+        $tableOptions = null;
+        if ($this->db->driverName === 'mysql') {
+            // http://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci
+            $tableOptions = 'CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE=InnoDB';
+        }
+
+        $this->createTable('{{%single_tree}}', [
+            'id'    => Schema::TYPE_PK,
+            'lft'   => Schema::TYPE_INTEGER . ' NOT NULL',
+            'rgt'   => Schema::TYPE_INTEGER . ' NOT NULL',
+            'depth' => Schema::TYPE_INTEGER . ' NOT NULL',
+        ], $tableOptions);
+        $this->createIndex('lft', '{{%single_tree}}', ['lft', 'rgt']);
+        $this->createIndex('rgt', '{{%single_tree}}', ['rgt']);
+    }
+}
--- a/sample-migrations/m150722_150100_multiple_tree.php
+++ b/sample-migrations/m150722_150100_multiple_tree.php
@ -0,0 +1,26 @@
+<?php
+
+use yii\db\Schema;
+use yii\db\Migration;
+
+class m150722_150100_multiple_tree extends Migration
+{
+    public function up()
+    {
+        $tableOptions = null;
+        if ($this->db->driverName === 'mysql') {
+            // http://stackoverflow.com/questions/766809/whats-the-difference-between-utf8-general-ci-and-utf8-unicode-ci
+            $tableOptions = 'CHARACTER SET utf8 COLLATE utf8_unicode_ci ENGINE=InnoDB';
+        }
+
+        $this->createTable('{{%multiple_tree}}', [
+            'id'    => Schema::TYPE_PK,
+            'tree'  => Schema::TYPE_INTEGER . ' NULL',
+            'lft'   => Schema::TYPE_INTEGER . ' NOT NULL',
+            'rgt'   => Schema::TYPE_INTEGER . ' NOT NULL',
+            'depth' => Schema::TYPE_INTEGER . ' NOT NULL',
+        ], $tableOptions);
+        $this->createIndex('lft', '{{%multiple_tree}}', ['tree', 'lft', 'rgt']);
+        $this->createIndex('rgt', '{{%multiple_tree}}', ['tree', 'rgt']);
+    }
+}