pulsarvp/vps-tools

<?php
    /**
     * @author    Evgenii Kuteiko <kuteiko@mail.ru>
     * @author    Anna Manaenkova <anna.manaenkova@phystech.edu>
     * @copyright Copyright (c) 2018
     */

    namespace vps\tools\base;

    use yii\db\ExpressionInterface;

    /**
     * @inheritdoc
     */
    class BaseOrderModel extends BaseModel
    {

        /**
         * Looking for the biggest order in the table, and the current model doing +1.
         *
         * @param bool $insert
         * @return bool
         */
        public function beforeSave ($insert)
        {
            if ($parent = parent::beforeSave($insert))
            {
                if ($this->isNewRecord)
                {
                    if ($this->hasAttribute('order') and empty($this->order))
                    {
                        $query = self::find()->select('order')->orderBy([ 'order' => SORT_DESC ]);

                        $condition = $this->orderCondition();
                        if ($condition !== null)
                        {
                            $query->where($condition);
                        }

                        $order = $query->scalar();

                        $this->order = !is_null($order) ? $order + 1 : 1;
                    }
                }
            }

            return $parent;
        }

        /**
         * Which order more than the remote model, do for order -1.
         */
        public function afterDelete ()
        {
            $parent = parent::afterDelete();

            if ($this->hasAttribute('order'))
            {
                $query = self::find()->where([ '>', 'order', $this->order ]);

                $condition = $this->orderCondition();
                if ($condition !== null)
                {
                    $query->andWhere($condition);
                }

                $objects = $query->all();
                foreach ($objects as $object)
                {
                    $object->order -= 1;
                    $object->save();
                }
            }

            return $parent;
        }

        /**
         * Looking for the next higher order, and changing places with it
         *  ```php
         *  $object->moveUp();
         *  ```
         */
        public function moveUp ()
        {
            if ($this->hasAttribute('order'))
            {
                $query = self::find()->where([ '>', 'order', $this->order ])->orderBy('order ASC');

                $condition = $this->orderCondition();
                if ($condition !== null)
                {
                    $query->andWhere($condition);
                }

                $object = $query->one();
                if ($object != null)
                {
                    $order = $object->order;
                    $object->order = $this->order;
                    $this->order = $order;
                    $object->save();
                    $this->save();
                }
            }
        }

        /**
         * Looking for the next descending order, and changing places with it
         *  ```php
         *  $object->moveDown();
         *  ```
         */
        public function moveDown ()
        {
            if ($this->hasAttribute('order'))
            {
                $query = self::find()->where([ '<', 'order', $this->order ])->orderBy('order DESC');

                $condition = $this->orderCondition();
                if ($condition !== null)
                {
                    $query->andWhere($condition);
                }

                $object = $query->one();
                if ($object != null)
                {
                    $order = $object->order;
                    $object->order = $this->order;
                    $this->order = $order;
                    $object->save();
                    $this->save();
                }
            }
        }

        /**
         * Make a selection of all models and assign the first model order = 1, all subsequent +1 and save
         *  ```php
         *  Model::rebuildOrder();
         *  ```
         * @param string|array|ExpressionInterface|null $whereCondition
         * @param string|array|ExpressionInterface|null $order
         */
        public static function rebuildOrder ($whereCondition = null, $order = null)
        {
            if ($order === null)
            {
                $order = [ 'order' => SORT_ASC ];
            }

            $query = self::find()->orderBy($order);
            if ($whereCondition !== null)
            {
                $query->where($whereCondition);
            }

            $objects = $query->all();
            foreach ($objects as $k => $object)
            {
                $object->order = $k + 1;
                $object->save();
            }
        }

        /**
         * Additional condition to narrow an entity selection during a reorder.
         *
         * @return string|array|ExpressionInterface|null
         */
        protected function orderCondition ()
        {
            return null;
        }
    }