Javascript：如何取消表单提交而不返回false？

Question

I have a form submission code, which does an AJAX call & redirects from there- if match found.

But, somehow, return false is omitted & the form is getting submitted.

I dont want to use return false, & needs to cancel submission for all cases. Is there any jquery method for that?

function getLogin()
{       
    //cancel form submission code here


    $username = $('#username').val();
    $password = $('#password').val();
    console.log('Logging- '+$username+' - '+$password);

    callAjaxService($username, $password);  // redirects according to response from this method
}

HTML

 <form action=""  method="get" onSubmit="getLogin();">

Actual code is in Jquery-mobile & having issue with return false; in the end of the getLogin() function- it cant stop Submitting the form.

Answer 1

Assuming that the getLogin is bound to a form submit button/link, you could use preventDefault and stopPropagation

function getLogin(e)
{       
    //cancel form submission code here
    e.preventDefault();
    e.stopPropagation();
}

Get rid of onSubmit="getLogin();"

<form id="uniqueID" action=""  method="get">

and then use ready

$(function(){
    $("#uniqueID").click(getLogin);
})

Answer 2

I am not sure how the getLogin() is called? And Do you have a button like <input type="submit" onclick="getLogin()"> which submits the form.

If so, add a click handler and implement the code there as below,

HTML:

<input type="submit" onclick="getLogin()" id="submit_btn">

JS:

$('#submit_btn').click (function (e) {
     e.preventDefault(); //this should stop the form submission.

     getLogin();
});

Answer 3

i dont know for sure if this work, but this i would try rigging the submit handler:

$('#myform').submit(function(){
  var user = $('#username').val();
  var pw = $('#password').val();
  $.ajax(..., { success: function(data){
    if( data.condition )$('#myform').submit();
    else window.location = 'redirect.html';
  });
  return false;  
});

after reading docs for 10 secs, i noticed, this can be combined with the preventDefault mentioned elsewhere:

  $('#myform').submit(ev, function(){ 
       ev.preventDefault();
   ...

but return false should work as well.

Answer 4

Why dont you just set the action-Parameter right?

action="javascript:;"

BTW: an even better solution would be to set the action-Parameter to this at $(window).load(..). Why? Because if you want the form to be usable when JS is deactivated it is necessary to do so.

Answer 5

If handler is not returning false, either a logic problem..or more likely an error thrown within handler before code reaches the return

Try using event.preventDefault() before your other code in handler

http://api.jquery.com/event.preventDefault/

Answer 6

function getLogin()
{
    var e = window.event;
    e.preventDefault();


    $username = ...
    ...

}