jQuery Forum

Same issue here

I believe the problem arises, because GM wraps the results of method calls into an XPCNativeWrapper object, which then breaks the in functionality, as well as access to object properties via the obj[attr] syntax.

I propose the following fix:
    var eventSupported = function( eventName ) {
        var
            el = document.createElement("div"),
            unwrappedEl = el.wrappedJSObject || el;
        eventName = "on" + eventName;

        var isSupported = (eventName in unwrappedEl);
        if ( !isSupported ) {
            el.setAttribute(eventName, "return;");
            isSupported = typeof unwrappedEl[eventName] === "function";
        }
        el = null;
        unwrappedEl = null;

        return isSupported;
    };

With this fix events work properly in Greasemonkey 0.8.20100211.5 on FF 3.5.8 in Ubuntu.
Also, events still work for 'normal' jQuery use (i.e. not in GM).

Obviously, this would have to be tested more thoroughly.

I have attached a diff file against jquery.1.4.2.js .

I'd be proud, if this really fixes the problem in all instances without breaking anything. :)

I am brand new to GM (not to jQuery, though), and hope that I've come to the correct conclusion as to what the cause of the problem is.

Edit 3/26:

Sorry, I forgot:

1. I fully expect there to be a few more things not to be working in GM. For example, some things involving xmlHttpRequest will almost certainly not be working out of the box, but hopefully they can also be fixed in a way that doesn't introduce regression.
2. I've tried to fix the immediate problem in a way that doesn't introduce security loopholes into GM user scripts. That's why the unwrappedEl is only used in the two places where it's actually needed for GM, hopefully in a non-threatening reading context only.
   

I also found the same results as thpickert, and I also have a patch that keeps functionality, but we have to use el.wrappedJSObject. I only used accessed it when it was absolutely needed, though, in the catch() blocks for cleanliness.

I really don't care which solution gets implemented, but I'd like to see it happen so I can stop using 1.3.2 and live in the now.

   var eventSupported = function( eventName ) {
       var el = document.createElement("div");
       eventName = "on" + eventName;
       var isSupported = false;
       try {
           isSupported = (eventName in el);
       } catch(e) {
           isSupported = el.wrappedJSObject && (eventName in el.wrappedJSObject);
       }
       if ( !isSupported ) {
           el.setAttribute(eventName, "return;");
           try {
               isSupported = typeof el[eventName] === "function";
           } catch(e) {
               isSupported = el.wrappedJSObject && typeof el.wrappedJSObject[eventName] === "function";
           }
       }
       el = null;
       return isSupported;
   };

EDIT: Fix cases where features are unsupported and GM is not in use.

FYI, background on this problem:

Introduced: http://dev.jquery.com/ticket/5267
Noticed: http://dev.jquery.com/ticket/5833
Also noticed: http://dev.jquery.com/ticket/6131

It would be nice if the Firefox functionality was extended through Greasemonkey, which would prevent/fix this problem, so I posted http://github.com/greasemonkey/greasemonkey/issues/#issue/1104

EDIT: Nevermind, I hadn't done my research on XPCNativeWrapper thoroughly beforehand.  This should definitely be addressed in jQuery.

Please be very careful about suggesting the use of wrappedJSObject.  Doing so has the potential to completely break Greasemonkey's security model.  This usage is probably safe, but it is a slippery slope.

I thought of a relatively simple solution today. I put an unmodified jQuery script into an anonymous function to be required (via @require) for a Greasemonkey script. The anonymous function has an argument named window, and has Greasemonkey's unsafeWindow passed to it. jQuery then loads correctly in the non-wrapped context (as if it were just part of the web page), but then the anonymous function returns the jQuery object at the same time deletes all references to jQuery via jQuery.noConflict(). The returned value is saved to $ and jQuery, but since it is run in the Greasemonkey sandbox, $ and jQuery are only usable from within the Greasemonkey script.

Now, jQuery resides in the unsafeWindow, but since all references to it in unsafeWindow are removed and only the script has the reference to it, the page cannot see it after it loads. It works just as if it were part of the page, but without being detectable.  Typing in javascript:jQuery('body').css('background-color','#f00') into the address bar won't work because jQuery and $ aren't saved into the unsafeWindow.

Since Greasemonkey saves it as $ and jQuery, you can also use un-modified plugins using more @require lines (tested - works so far with the plugins I am using)

Attached is the file I made. There are details in it on what it is, how to use it, and a template of the wrapper function with directions to update your Greasemonkey jQuery. It is a javascript file, but since .js files can't be uploaded, convert the .txt file to a .js file.

Hi,
Is John's solution incorporated in 1.4.3?

I just wanted to point out an excellent article on how to fix this issue: http://joanpiedra.com/jquery/greasemonkey/

Not my idea so give the site owner credit, I just found that it works for me on 1.4.4.

1. var $;
   
   // Add jQuery
       (function(){
           if (typeof unsafeWindow.jQuery == 'undefined') {
               var GM_Head = document.getElementsByTagName('head')[0] || document.documentElement,
                   GM_JQ = document.createElement('script');
       
               GM_JQ.src = 'http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js';
               GM_JQ.type = 'text/javascript';
               GM_JQ.async = true;
       
               GM_Head.insertBefore(GM_JQ, GM_Head.firstChild);
           }
           GM_wait();
       })();
   
   // Check if jQuery's loaded
       function GM_wait() {
           if (typeof unsafeWindow.jQuery == 'undefined') {
               window.setTimeout(GM_wait, 100);
           } else {
               $ = unsafeWindow.jQuery.noConflict(true);
               letsJQuery();
           }
       }
   
   // All your GM code must be inside this function
       function letsJQuery() {
           alert($); // check if the dollar (jquery) function works
           alert($().jquery); // check jQuery version
       }