Question

When an event handler function gets registered like this:

element.onload = function() 
{   
    var something = Selector("identifier", "inline", 1).FadeIn("inline", 1);
    CenterElement(something);
};

Is there a way to stop the execution once it starts from the inside of another handler function? Let that handler function look like this:

another.onclick = function() 
{
    //Cancel the execution of the above function here
    document.getElementById("start").innerHTML = "Start Slideshow"; 
    this.FadeOut(); 
};

Selector returns a special wrapper object that isn’t relevant for the question itself so the implementation has been omitted.

It’s quite known that it’s possible to prevent execution of a handler function by assigning undefined to the handler variable, but how to stop it if it’s already begun executing?

Answer 1

You’re missing an important concept here.

In javascript, there is only one thread of execution. While you might think that onclick gets called while onload is executing, that is plain false.

I don’t know what framework you’re using, but in jQuery you could do the following:

another.onclick = function() 
{
    //Cancel the execution of the above function here
    Selector("identifier", "inline", 1).stop();
    // ...other stuff
};