JSONView 0.4 was just approved on addons.mozilla.org.
This one is mostly a bugfix release from 0.3, but I couldn’t let it go out without one new feature, so I finally added support for content negotation. This means that you can go to the new JSONView options dialog (in the Addons menu) and enable sending the “application/json” content type with your HTTP Accept header. Some applications (like some Ruby on Rails websites) are set up to return JSON if you ask for it via the HTTP Accept header, and XML or HTML otherwise. This means thay you can now specify a preference for JSON, which should help when you’re in that situation. I specifically made sure it works with CouchDB, which is an exiting document-based database with a JSON API. Before this option, CouchDB would return plain text to browsers, but now you can make it send JSON that’ll be nicely formatted by JSONView. Note that the option to modify the HTTP Accept header isn’t on by default because many people won’t need it, and it has the potential to screw up some websites that don’t expect browsers to ask for JSON. That said, I’m sure this will be helpful in a bunch of situations.
On the bugfix side, I fixed the issue I mentioned in my post about JSONView 0.3 where values that were 0 or false wouldn’t show up at all as a result of some overzealous error-checking. I also hunted down an infuriating bug where JSON documents would sometimes report as invalid when Firebug was on. This took a while to track down, but apparently Firebug slows down the loading of the document enough to mess with how I was reading a stream (and I had to be careful not to re-trigger an earlier bug that could cause Firefox on OSX to crash.) Anyway, it’s fixed now, and everybody should see more reliable document rendering, Firebug or not. For those living on the edge, JSONView is also marked as compatible up to Firefox 3.7a1pre, so you should have no trouble installing it on Minefield or the upcoming Firefox 3.6 alpha.
One thing that might stand out is that the new options dialog might not be localized for your language. JSONView’s localizations are handled by the generous volunteers at Babelzilla, which is great for me, but not as great when I want to rush out a release with important bugfixes. In this case I chose to ship 0.4 before all the new localizations had arrived, but I’ll add them all in again for the next release once the translators have caught up.
So grab JSONView 0.4 from addons.mozilla.org, or just update your extensions if you’ve already got it installed. As usual, feel free to send me feedback as comments on this post, and file bugs and feature requests at Google Code.