yii\mongodb\file\ActiveRecord::updateInternal PHP Method

    protected function updateInternal($attributes = null)
    {
        if (!$this->beforeSave(false)) {
            return false;
        }
        $values = $this->getDirtyAttributes($attributes);
        if (empty($values)) {
            $this->afterSave(false, $values);
            return 0;
        }
        $collection = static::getCollection();
        if (isset($values['newFileContent'])) {
            $newFileContent = $values['newFileContent'];
            unset($values['newFileContent']);
        }
        if (isset($values['file'])) {
            $newFile = $values['file'];
            unset($values['file']);
        }
        if (isset($newFileContent) || isset($newFile)) {
            $fileAssociatedAttributeNames = ['filename', 'uploadDate', 'length', 'chunkSize', 'md5', 'file', 'newFileContent'];
            $values = array_merge($this->getAttributes(null, $fileAssociatedAttributeNames), $values);
            $rows = $this->deleteInternal();
            $insertValues = $values;
            $insertValues['_id'] = $this->getAttribute('_id');
            if (isset($newFileContent)) {
                $collection->insertFileContent($newFileContent, $insertValues);
            } else {
                $fileName = $this->extractFileName($newFile);
                $collection->insertFile($fileName, $insertValues);
            }
            $this->setAttribute('newFileContent', null);
            $this->setAttribute('file', null);
        } else {
            $condition = $this->getOldPrimaryKey(true);
            $lock = $this->optimisticLock();
            if ($lock !== null) {
                if (!isset($values[$lock])) {
                    $values[$lock] = $this->{$lock} + 1;
                }
                $condition[$lock] = $this->{$lock};
            }
            // We do not check the return value of update() because it's possible
            // that it doesn't change anything and thus returns 0.
            $rows = $collection->update($condition, $values);
            if ($lock !== null && !$rows) {
                throw new StaleObjectException('The object being updated is outdated.');
            }
        }
        $changedAttributes = [];
        foreach ($values as $name => $value) {
            $changedAttributes[$name] = $this->getOldAttribute($name);
            $this->setOldAttribute($name, $value);
        }
        $this->afterSave(false, $changedAttributes);
        return $rows;
    }