Question

I have a long a web form. I’m wondering if I should bind() to each <input> element separately (what I really want) or should I only define one bind() all of the input elements then do an if-then inside the handler to handle the specific element?

Answer 1

jQuery’s event handlers are implemented in JavaScript (they have to be).

In general, it’s best to use a single handler for the entire form, rather than a large number of individual elements. But jQuery’s live feature can help quite a lot, it does a lot of the plumbing for event delegation for you. For example:

$("#formid input").live('focus', function(event) {
    var field = $(this);
    // `field` now references the field that was focussed
});

…watches all fields in your formid form for focus events. If you’re using jQuery 1.4, that works even with the focus event in that example (even though focus doesn’t bubble, and so is usually tricky to use with event delegation). Prior to 1.4 that won’t work, but bubbling events like click and such do.