src/TaggableBehavior.php
public function afterSave()
    {
        if ($this->_tagsList === null) {
            return;
        }
        $relation = $this->owner->getRelation('tagsList', false);
        if (!($relation instanceof ActiveQuery)) {
            return;
        }
        if (!$this->owner->getIsNewRecord()) {
            // clear old tags
            $this->beforeDelete();
            $this->afterDelete();
        }
        /** @var ActiveRecord $relationClass */
        $relationClass = $relation->modelClass;
        $ownerTagsList = [];
        foreach ($this->_tagsList as $tagText) {
            /* @var ActiveRecord $tag */
            $tag = $relationClass::findOne(['text' => $tagText]);
            if ($tag === null) {
                $tag = new $relationClass();
                $tag->setAttribute('text', $tagText);
            }
            $tag->setAttribute('count', $tag->getAttribute('count') + 1);
            if ($tag->save()) {
                $ownerTagsList[] = [$this->owner->getPrimaryKey(), $tag->getPrimaryKey()];
            }
        }
        if (!empty($ownerTagsList)) {
            $this->owner->getDb()
                ->createCommand()
                ->batchInsert($relation->via->from[0], [key($relation->via->link), current($relation->link)], $ownerTagsList)
                ->execute();
        }
    }
public function afterSave()
    {
        if ($this->_tagsList === null) {
            return;
        }
        $relation = $this->owner->getRelation('tagsList', false);
        if (!($relation instanceof ActiveQuery)) {
            return;
        }
        if (!$this->owner->getIsNewRecord()) {
            // clear old tags
            $this->beforeDelete();
            $this->afterDelete();
        }
        /** @var ActiveRecord $relationClass */
        $relationClass = $relation->modelClass;
        $ownerTagsList = [];
        foreach ($this->_tagsList as $tagText) {
            /* @var ActiveRecord $tag */
            $tag = $relationClass::findOne(['text' => $tagText]);
            if ($tag === null) {
                $tag = new $relationClass();
                $tag->setAttribute('text', $tagText);
            }
            $tag->setAttribute('count', $tag->getAttribute('count') + 1);
            if ($tag->save()) {
                $ownerTagsList[] = [$this->owner->getPrimaryKey(), $tag->getPrimaryKey()];
            }
        }
        if (!empty($ownerTagsList)) {
            $this->owner->getDb()
                ->createCommand()
                ->batchInsert($relation->via->from[0], [key($relation->via->link), current($relation->link)], $ownerTagsList)
                ->execute();
        }
    }
After owner save action