Yii2: Submit event is triggered twice #4955

[thiagotalma]

When a form is submitted by clicking on the "submit" button, the script submits the form again.

When there is an on('submit') or on('beforeSubmit'), the function is executed twice.

[qiangxue]

It's expected that the submit event is triggered twice: during the first time validation will be performed; if the validation succeeds, it will submit the form, which again triggers the submit event.
The beforeSubmit event is only triggered once.

[thiagotalma]

Thank you @qiangxue

This change may cause some difficulty for developers.

It is worth documenting somewhere, the correct format to submit forms by AJAX.

I do not know if it's the best way, but I'm doing this way (besides beforeSubmit already used before the change, it was necessary to add on('submit')):

$("#form").on('beforeSubmit', function(e) {
    $.post($(this).attr("action"), $(this).serialize())
        .done(function(result) {
            $('#modal').modal('hide');
        })
        .fail(function() {
            alert("Error.");
        }
    );
}).on('submit', function(e){
    e.preventDefault();
});

[qiangxue]

Thanks. Will add this to the guide.

[kshitizsingh]

@thiagotalma
Thanks for your help. You figure this out right. this was creating problem.

[qiangxue]

The expected way should be

$("#form").on('beforeSubmit.yii', function(e) {
    $.post($(this).attr("action"), $(this).serialize())
        .done(function(result) {
            $('#modal').modal('hide');
        })
        .fail(function() {
            alert("Error.");
        }
    );
    return false;
});