Joe Walker - debug tag

2 Wrongs Making a Right: (false && false) = true

Thu, 28 Feb 2008 23:43:33 GMT

I just had one of those times when I thought I totally lost the ability to do simple logic. Take a look at this screenshot:

I'll break it down: req.readyState = 4, and batch.async = false.

Last time I checked 4 = 4. So blatantly (4 != 4) is false. And false && false is blatantly uber false, as true as Alice Cooper covering Barbie Girl.

So seeing firebug step through if (false) and onto the return statement made about as much sense as trying to raise Schrodinger's cat in a séance.

I think it's another quirk in Firebug. This time it's simply something funky going on with "step over".

The moral is: Firebug sometimes lies to you about where the current line is.

This is all part of me adapting DWR so that it can be used as a connector between Jaxer and some Java server. More on that in a bit.

The case of James Gosling and the missing Javascript Debuggers

Thu, 20 Apr 2006 23:08:30 GMT

James Gosling recently claimed that: "None of the browsers has decent debugging hooks".

I've got a list of of Javascript debuggers that might be interesting. I think they must use the debugging hooks in Firefox and IE.

Venkman for Firefox
Firebug for Firefox (In development)
MS Visual Studio Express for IE
MS Script Debugger for IE
Script Editor for IE
SplineTech Javascript Debugger for IE (not used it)
MyEclipse for Firefox

I'm sure there must be something in IntelliJ too, but I don't have a link. Maybe there is something on the cards over at JSEclipse too.

Perhaps James' issue is that the the hooks in FF/IE are not 'decent'? I guess there's also a very good chance that he was misquoted or misunderstood - it wouldn't be the first time a journalist had done that. But if not, it would be good to understand why he discounts this list.

Opera and Safari are conspicuous by their absence. Anyone have any good solutions? And I'm sure there are other debuggers missing.

Which is your favorite?

Javascript Debugger Updated (v0.9.86)

Thu, 02 Feb 2006 08:29:37 GMT

I've updated Venkman, the Javascript debugger for Firefox. The changes include:

Now works on Firefox 1.5.0.1
Fixed the multiple load bug - previously if you started Venkman, and then closed it, you couldn't get it back until you re-started Firefox.
A start to getting it to work under Thunderbird and Flock

Get it here.

Technorati tags: javascript, debugging, venkman, firefox

A new home for my Venkman patch

Fri, 04 Nov 2005 10:17:41 GMT

The Firefox Javascript debugger has been looking a bit unloved and quite a few people have been using my patch, so I've created a new home for the patch. The new page is a much better place to link to than the old blog entry.

The new page has the advantage that I've done the install wizardry to make Venkman installable directly without needing to download it first.

There is a known bug where you can't launch Venkman twice in a browser session. I think this is because the close button on Venkman just hides the window rather than releasing all the resources.

If you want to install Venkman on Firefox 1.5, you know where to go.

Technorati tags: javascript, debugging, venkman, firefox

Javascript Debugger (Venkman)

Fri, 07 Oct 2005 10:14:04 GMT

Update: I've created a new permanent page for my Venkman patch:

Venkman for Firefox 1.5

Old blog content:

Firefox 1.5 beta 2 is ready for download. See also the release notes and the list of new features. This is the last planned beta before the release candidates.

I've updated my hack on the Javascript debugger (Venkman) so it will load into the new browser. You can get the installer package.

Please give me a bit of feedback if you find this useful.