How to use callback on $.post to get returned data (async function problem)

Question

I'd like to get true or false from $.post by calling abc(). I found this answer, but I don't get it to work.

Can someone give me a short example with my code?

function abc() {
    form = $('form');
    formData = form.serialize();

    $.post('file.php', formData, function(result) {
        form.each(function() {
            if (result === this.id) {
                return true;
                error = true;
            }
        });

        if (error === false) { // no error
            return true;
        }
    });
}

if (abc()) {
    // true // <- doesn't work, because $.post is an async function
}

Answer 1

You can achieve it by returning promise value, Then check it by using done method.

function abc() {
   form = $('form');
   formData = form.serialize();

   return $.post('file.php', formData);
}

abc().done(function(result){
    if(result === 'abc')
    // do something.
});

You can also use Callback function like this

function abc(mycalback) {
    form = $('form');
    formData = form.serialize();

    $.post('file.php', formData, mycalback);
}

function mycalback(response) {
    var result = false;
    form.each(function() {
            if (response=== this.id) {
                return true;
                result = true;
            }
        });
    return result;
}