jQuery live with the ready or load event

问题

I'm using the jQuery Tools tooltip plugin, which is initialized with $('selector').tooltip(). I'd like to call this on any current or future .tooltipper element. I figured that the following would work:

$('.tooltipper').live('ready', function(){
  $(this).tooltip()
}

But it was unsuccessful---the ready event did not fire. The same for load. I've read that livequery can produce the result of I'm looking for, but surely there is a way to use jQuery .live() to pull it off, considering the documentation says that it works for all jQuery events, of which I believe ready is one.

回答1:

Quoted from the jQ API (http://api.jquery.com/live/):

In jQuery 1.3.x only the following JavaScript events (in addition to custom events) could be bound with .live(): click, dblclick, keydown, keypress, keyup, mousedown, mousemove, mouseout, mouseover, and mouseup.

As of jQuery 1.4 the .live() method supports custom events as well as all JavaScript events.

As of jQuery 1.4.1 even focus and blur work with live (mapping to the more appropriate, bubbling, events focusin and focusout).

As of jQuery 1.4.1 the hover event can be specified (mapping to "mouseenter mouseleave").

.live() does not appear to support the ready event.

回答2:

To add to HurnsMobile's excellent answer; Looking at bindReady(), which is the internal call that jQuery makes to bind to the document load event every time you call $(some_function) or $(document).ready(some_function) we see why we cannot bind to "ready":

bindReady: function() {
        if ( readyBound ) {
            return;
        }

        readyBound = true;

        // Catch cases where $(document).ready() is called after the
        // browser event has already occurred.
        if ( document.readyState === "complete" ) {
            return jQuery.ready();
        }

        // Mozilla, Opera and webkit nightlies currently support this event
        if ( document.addEventListener ) {
            // Use the handy event callback
            document.addEventListener( "DOMContentLoaded", DOMContentLoaded, false );

            // A fallback to window.onload, that will always work
            window.addEventListener( "load", jQuery.ready, false );

        // If IE event model is used
        } else if ( document.attachEvent ) {
            // ensure firing before onload,
            // maybe late but safe also for iframes
            document.attachEvent("onreadystatechange", DOMContentLoaded);

            // A fallback to window.onload, that will always work
            window.attachEvent( "onload", jQuery.ready );

            // If IE and not a frame
            // continually check to see if the document is ready
            var toplevel = false;

            try {
                toplevel = window.frameElement == null;
            } catch(e) { //and silently drop any errors 
                    }
                    // If the document supports the scroll check and we're not in a frame:    
            if ( document.documentElement.doScroll && toplevel ) {
                doScrollCheck();
            }
        }
    }

To sum it up, $(some_function) calls a function which binds to:

DOMContentLoaded
onreadystatechange (DOMContentLoaded)
window.load / onload

Your best bet would be to bind to those actions that might create new .tooltipper elements, rather than trying to listen for the ready event (which happens only once).

回答3:

HurnsMobile is right. JQuery live does not support the ready-event.

This is why I created a plugin that combines the two. You register your callback once, and then you will need to call the plugin once for content you add manually.

$.liveReady('.tooltipper', function(){
  this.tooltip()
});

Then when creating new content:

element.html(somehtml);
element.liveReady();

$('<div class="tooltipper">...').appendTo($('body')).liveReady();

A demo is available here: http://cdn.bitbucket.org/larscorneliussen/jquery.liveready/downloads/demo.html

Check out the introductory post here: http://startbigthinksmall.wordpress.com/2011/04/20/announcing-jquery-live-ready-1-0-release/

Also have a look at http://docs.jquery.com/Plugins/livequery, which listenes for changes on the dom.

来源：https://stackoverflow.com/questions/3196404/jquery-live-with-the-ready-or-load-event

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dom

jquery

jquery-tools