Validation Rules for the Model.

yii-ar-rules.php

class MyModel {

    /**
     * @return array validation rules for model attributes.
     */
    public function rules()
    {
        return array(
            array(
                'element',
                'type',
                'type' => 'string'
            ),
            array(
                'content',
                'type',
                'type' => 'string'
            ),
            array(
                'suggestion',
                'type',
                'type' => 'string'
            ),
            array(
                'notes',
                'type',
                'type' => 'string'
            ),
            array(
                'id, seo_project_id, webpage_id, user_id',
                'numerical',
                'integerOnly' => true
            )

        );
    }
}