Couple questions for the jQuery internals-aware folks. This is a bit long, sorry for that.
I'm working on beefing up error handling in a web application. I want to ensure that I'm catching all exceptions and handling them via my own UI system. The window.onerror function is part of the solution, but there's a known problem with Firefox (https://bugzilla.mozilla.org/ show_bug.cgi?id=312448) that prevents onerror being called when the exception is thrown inside an event handler. In looking for a solution that didn't require mucking about with each instance of event binding logic throughout the app, I ran across what seems like a reasonable solution here: (http://blogs.cozi.com/tech/ 2008/04/javascript-error-tracking-why-windowonerror-is-not- enough.html). The general idea is to override bind() and replace the passed in handler function with a function that wraps the original handler function in a try-catch block. So the code would look something like this: var jqBindFn = jQuery.fn.bind; $.fn.bind = function(type, data, fn) { if (!fn && data && typeof data === 'function') { fn = data; data = null; } if (fn) { var ofn = fn; var wfn = function() { try { ofn.apply(this, arguments); } catch ( ex ) { someGlobalErrHandler( ex ); } }; fn = wfn; } return jqBindFn.call(this, type, data, fn); }; Since all other event binding goes through bind(), it seems like this will easily add exception handling to all event handlers in my app. So I have two questions about this: (1) I haven't been using Javascript terribly long, so I'm not really sure if this approach has any significant costs or downsides. I mean, there's a performance hit by having the extra function calls. And again I suppose for the exception handling. But are there potential memory leak issues or is the performance hit likely to increase the longer a user uses an app with that "fix" in it? (2) It sort of seems like Mozilla isn't in any giant hurry to fix there bug. It probably doesn't make sense to add code to jQuery core to work around such an obscure bug for it's own sake. But I wonder if adding some exception handling capability to jQuery core makes any sense? It could do what it does for other areas of Javascript which is mitigate the browser differences. To be complete, it would need to employ onerror, add a try-catch block to document.ready(), and do something similar to the above for event handlers (only in mozilla). Thoughts? Is this just stupid?
