Javascript async callback

My problem is better explained in code:

//This code is triggered before ajax ObBegin. But I need f1 to return a boolean to either cancel or 开发者_如何学JAVAcontinue the event.
f1();

function f1(){
    $.modalWindow.Open(); //This is an async method, this is where my problem lies.
    //I need to freeze here and wait on a return value from one of the events below.
}

//In the modal window:

//An event which waits for the click event
$('.cancelBtn').click(function(){
    //How do I send false back to f1?
    closeModalWindow();
});

$('.yesBtn').click(function(){
    //How do I send true back to f1?
    closeModalWindow();
});

So basically what happens is this:

1. openModalWindow() opens a modal window that waits on a button click.
2. I want to pass the value back to f1 and return it.

Is there a way to fix this?

Use jQuery's Deferred objects. There's a good tutorial on it here, but you haven't actually shown enough of your own code for me to demonstrate how to wire it up with $.Deferred.

Here's a very basic demo of how to do this: http://jsfiddle.net/mattball/fNQ8J/. Basically, you have to pass callbacks around for asynchronous execution.

function openModalWindow(callback) {
    if (typeof callback !== 'function') callback = $.noop;
    $("#dialog-confirm").show().dialog({
        resizable: false,
        modal: true,
        buttons: {
            Yes: function() {
                $(this).dialog("close");
                callback(true);
            },
            No: function() {
                $(this).dialog("close");
                callback(false);
            }
        }
    });
}

function f1() {
    return $.Deferred(function(dfd) {
        openModalWindow(dfd.resolve);
    }).promise();
}

$('#clickme').click(function() {
    f1().then(function(result) {
        alert('f1 async returned: ' + result);
    });
});

There's no good way to do this, no. You'll have to refactor f1 so it can deal with asynchronicity.

f1() should be implemented as a callback for someAsyncFunc():

function someAsyncFunc(callback) {
    // open your modal window
    $(".theBtm").click(function() {
      // do your stuff
      if (typeof(callback) === "function") {
        callback(theValueYouWantToPass);
      }
    });
}

Called something like this:

someAsyncFunc(function(value) { f1(value); });