Question

I have a click function, for when a user logs out

$('#logout').click(function(){

    // update database and tell other users that this person has logged off

});

#logout is the id of a link (logout button)

The function will handle some ajax/php/database actions + sending a socketmessage and could easily take several miliseconds to complete

Can I trust that javascript/jquery completes that function before actually returning true (opens the link that is clicked)?

Or what would be a way do to make sure it completes it.. Starting with “return false”, and then only return true if it recieves an OK from php for example?

Answer 1

When an operation involves AJAX or any async operation, you can never do a “return”. Or else, you’d lose the essence of async.

Instead, hand over a callback to execute once it’s done. Or return a deferred object and have it listen if ajax is done.

$('#logout').click(function(e){
    //store location for later use
    var location = $(this).attr('href');
    //prevent link from being followed for now
    e.preventDefault();
    $.ajax({params}).done(function(e){
        //user logged out, follow link
        window.location = location;
    }
}

//while idle and waiting for ajax to complete
//do a moonwalk...