yii2 custom validation not working

Question

I need to compare 2 attribute value in the model and only if first value is lower than second value form can validate.I try with below code but it not worked.

controller

public function actionOpanningBalance(){

     $model = new Bill();
     if ($model->load(Yii::$app->request->post())) {
        $model->created_at = \Yii::$app->user->identity->id;
        $model->save();
      }else{
       return $this->render('OpanningBalance', [
            'model' => $model,
        ]);
     } 
}

Model

public function rules()
{
    return [
        [['outlet_id', 'sr_id', 'bill_number', 'bill_date', 'created_at', 'created_date','bill_amount','credit_amount'], 'required'],
        [['outlet_id', 'sr_id', 'created_at', 'updated_at'], 'integer'],
        [['bill_date', 'd_slip_date', 'cheque_date', 'created_date', 'updated_date','status'], 'safe'],
        [['bill_amount', 'cash_amount', 'cheque_amount', 'credit_amount'], 'number'],
        [['comment'], 'string'],
        ['credit_amount',function compareValue($attribute,$param){
               if($this->$attribute > $this->bill_amount){
               $this->addError($attribute, 'Credit amount should less than Bill amount');
    }],           
        [['bill_number', 'd_slip_no', 'bank', 'branch'], 'string', 'max' => 225],
        [['cheque_number'], 'string', 'max' => 100],
        [['bill_number'], 'unique']
    ];
}
}

It's going in to the validator function but not add the error like i wanted

$this->addError($attribute, 'Credit amount should less than Bill amount');

anyone can help me with this?

Answer 1

If the validation is not adding any error, it's most likely being skipped. The issue is most likely becasue of default rules behaviour whereby it skips empty or already error given values as per here: https://www.yiiframework.com/doc/guide/2.0/en/input-validation#inline-validators

Specifically:

By default, inline validators will not be applied if their associated attributes receive empty inputs or if they have already failed some validation rules. If you want to make sure a rule is always applied, you may configure the skipOnEmpty and/or skipOnError properties to be false in the rule declarations.

So you would need to set up the skipOnEmpty or skipOnError values depending on what works for you:

[
    ['country', 'validateCountry', 'skipOnEmpty' => false, 'skipOnError' => false],
]