Cannot prevent Submit based on ajax check

Question

I am a java/jquery novice and struggling with the following:

$(document).ready(function() {
//Prevent SUBMIT if Session setting = On (Ajax)
$('#formID').submit(function(e) {
    var prevent = false;
    $.ajax({
        type: "POST",
        url: "url/to/ajax_file.php",
        cache: false,
        success: function(res){
            if(res == "On") { alert('Session is ON so submit should be prevented'); prevent = true; }
        }
    });
    if (stop2) { e.preventDefault(); }
});

});

The session setting is returned ok, and the alert is presented. But I also want to prevented the form submit if the session setting returned = 'On'. This is not happening. There is obviously something I do not understand, any advice?

Possible duplicate of [How do I return the response from an asynchronous call?](http://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) — Yury Tarabanko, Feb 09 '16 at 06:51

score 2 · Answer 1 · answered Feb 09 '16 at 06:49

2

You can't do that because of the asynchronous nature of ajax requests, instead in the submit handler you need to directly prevent the default action then in the ajax handler you can submit the form programatically.

$(document).ready(function() {
  //Prevent SUBMIT if Session setting = On (Ajax)
  $('#formID').submit(function(e) {
    e.preventDefault();
    var form = this;
    $.ajax({
      type: "POST",
      url: "url/to/ajax_file.php",
      cache: false,
      success: function(res) {
        if (res == "On") {
          alert('Session is ON so submit should be prevented');
        } else {
          form.submit();
        }
      }
    });
  });
});

answered Feb 09 '16 at 06:49

Arun P Johny

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Thanks! Prevents submit if res == 'On', but does not submit if res!== 'On'. Console says:"Uncaught TypeError: form.submit is not a function" – labbetuss Feb 09 '16 at 07:13
do you have a button named/id as `submit` in your form... if so rename the button – Arun P Johny Feb 09 '16 at 07:19
Indeed I had, several of them, just tested ok, thanks! – labbetuss Feb 09 '16 at 07:25

Cannot prevent Submit based on ajax check

1 Answers1