当yii2中的验证器无法正常工作时

Question

On one of my view file in project i am using when validator for defining some validation for a model but its not working properly may be because i dont know how to use that validator. Here is the model code of that table

       return [
        [['event_id', 'user_id'], 'required'],
        [['event_id', 'user_id'], 'integer'],
        [['is_mandatory'], 'boolean'],
        [['answer'], 'string', 'max' => 250],
        [['answer'], 'required', 'when' => function($model){
            return $model->is_mandatory == 1; }]
    ];

Here is my view code and yes i am creating this field on the view file with the instance because to create those fields depends on other inputs.

        $modelAnswers = new Answers();
        $modelAnswers->is_mandatory = 0;

        echo $form->field($modelAnswers, "answer",[
            'template' => ' <div class="row"><div class="col-lg-6 col-md-6 col-sm-6 col-xs-6"><label>{label}</label></div><div class="col-lg-4 col-md-4 col-sm-6 col-xs-8">{input}{error}{hint}</div></div>'
        ])->textInput(['maxlength' => true]);

But it always prints the field as required. I can see in the debugger that $model is assigned the value correctly. Whats wrong with the validator here??

Answer 1

The when() validation is only there for server-side validation, and will only evaluate when the form is submitted. If you want to display the field as required or not depending on the value of is_mandatory then you have two options.

Firstly, you can use the whenClient() method to add client-side validation. This is what I use on my own forms, and involves writing a javascript function that will determine if the field is required or not, and it will then apply the relvant classes. To do this, you will need to include the is_mandatory field somewhere on your form, probably as a hidden field, and you wil need to enable clientValidation on the form.

Secondly, you could simply adapt the template for the field so that the error messages are not included unless is_mandatory is set to true. This will involve rewriting the field label.

echo $form->field($modelAnswers, "answer",[
            'template' => ' <div class="row"><div class="col-lg-6 col-md-6 col-sm-6 col-xs-6"><label class="{$modelAnswers->is_mandatory ? 'required' : ''}">Name of label here</label></div><div class="col-lg-4 col-md-4 col-sm-6 col-xs-8">{input}{error}{hint}</div></div>'
        ])