yii2 disable the rules if a checkbox is selected - yii2

Question

In the active form, I have 3 textinput and one checkbox.
All the 3 textinputs have rules that says cannot be empty. What I want is if the checkbox is clicked, It will disable the rules and will save the empty record in the database.
here is screen shot of the active form..

Answer 1

You could define the rules that way (using when):
public function rules()
{
return [
['cancelled', 'boolean'],
['checkNumber', 'required'],
['payee', 'required', 'when' => function ($model) {return !$model->cancelled;}],
['particulars', 'required', 'when' => function ($model) {return !$model->cancelled;}],
];
}
You may want to add whenClient as well to let the browser check this before it submits the form.

Answer 2

You can do something like this:
$model = new SomeForm();
if ($model->load(Yii::$app->request->post())){
if ($model->checkbox == true) $model->scenario = 'checked';
}
// your model rules:
[['name', 'email', 'subject', 'body'], 'safe', 'on' => 'checked']
or alternatively You can do this:
if ($model->checkbox == true) $model->save(false); //this will disable any validation so be carefull
edit:
if You need cliend side validation switch, You have to use this:
[['name', 'email', 'subject', 'body'], 'required', 'when' => function ($model) {
return $model->cancelled == '0';
}, 'whenClient' => new JsExpression("function (attribute, value) { return $('#mailform-cancelled').val() == '0';}")]