TextMate and the "Edit In..." Feature

I’ve had my eye, idly, on the TextMate editor for Mac OS X for some time. I don’t do much editing on my desktop – most development is done on a development server and all the glory of VIM (I admit it – I converted from EMacs a couple of years ago and have been generally happy every since). But I’ve been tinkering a bit more with things at both home and office and I’m always looking for things to make my day better, if possible.

For what little desktop text editing I’ve done in recent months, BBEdit’s free little brother TextWrangler has been decent for me: code coloring, decent editing support, but none of the automation or contextual intelligence that BBEdit might have. Having used BBEdit since “back in the day” (1996, perhaps earlier), I’m still fairly comfortable with it but am not comfortable using it for long periods. The classic Mac OS feel still bleeds through, and I’m still not sure how I feel about how TextWrangler implements “tabs”. I like the single window interface option, but switching between open files is unpredictable and seems based on recent access rather than the order they appear. There may be a setting somewhere to change this behavior, but I haven’t really cared enough. For how little I need to use it, it’s worth the free price.

TextMate, on the other hand, is a fully native Mac OS X editor built on the Cocoa framework that descended from NeXTStep. Cocoa has long had extremely nice text editing options that all Cocoa based applications pick up automatically. I forget that people still whine about lack of spell checking in web browser text areas. Why? Because Safari’s textareas use Cocoa’s text editing, and all Cocoa text areas pick up on the spell check options automatically. All Cocoa text editing also supports some basic EMacs navigation commands – control-A and control-E for beginning / end of line, and even the Emacs style cut and yank (control-k and control-Y) which operates independent of the normal system clipboard. Good for quickly moving lines around. So while all applications can stylize things differently, there is a lot of very powerful and flexible text editing / viewing / manipulating features built in that work the same whether you’re editing an element in OmniOutliner or setting notes on an iCal event or using TextEdit – the free plain and rich text editor that seems to serve as a showcase for all that the text system in Cocoa can do. For example, when I upgraded to Mac OS X 10.4 (or maybe it was back with 10.3?) that there were named style options in TextEdit, which came in handy right away for some small documents I was working on. When I opened up Aquaminds NoteTaker after doing the upgrade, I saw that the same named styles system was available in there as well. And it appears that in the Mac OS X 10.4.4 update, released recently, that the text system has learned a new trick: rectangular selection. I can clip some code from the Python interpreter running in Terminal and paste it into just about anything – Safari, TextEdit, TextMate, Stickies even!, and by holding down the ‘option’ key (the mouse takes on a crosshair cursor) I can select and cut the leading characters of the interpeter (the >>> and the ...).

So – Cocoa’s text editing system is cool. Applications can all do their own thing, but almost all of them offer the same great editing features that are far and beyond what you see in other major operating environments. What does this have to do with TextMate?

I found out today that there’s a command in TextMate to install a Edit in TextMate… command. It installs an Input Manager which is a way for other tools to augment the text input system. On my desktop, I have a very old “platform completed input” manager, which I never really used. It was released in the early Mac OS X days, I don’t know by whom. Besides, auto-completion is now a built in feature of Mac OS X text input. I always thought it was a cool example of how the system could be extended. TextMate plugs in using this system, adding a new command and shortcut to the Edit menu. So right now, I fired up Blogger (which doesn’t support ‘rich text’ editing in Safari) and hit control-command-E and boom! TextMate!

TextMate is also a fascinating example of Mac / Unix integration. It’s a very good looking application. Text, of course, renders beautifully. And it’s incredibly extensible. It’s not a super-programmatic environment unto itself like Emacs. Instead it uses environment variables, shell commands, and launches into different programming languages (Python, Ruby, Perl, Shell Scripting) to do operations on text. So when I fired this entry up out of Safari, I can write away here in Textile. There’s a command to convert it to textile which just runs through Textile.rb. And then, just for fun, I made a command that uses html2text.py (which is in the Markdown bundle for TextMate), and I can turn the Textile source into Markdown, which is done through Python. I can convert it back to HTML from the Markdown bundle which uses Markdown.pl, which is (obviously) Perl. I’m impressed with how nicely this all flows together.

Why is it so exciting though? Good question. I’m about to do some hard work over the next couple of weeks on a Zope 2 based product, which has a lot of its major cough “logic” moved into disk based Python components but has some pretty hairy templates and a thin layer of Python Scripts in the ZODB. Most ZODB development is done through the web, although there are FTP and WebDAV options (TextWrangler supports direct FTP editing). There are advantages and disadvantages to Zope’s through-the-web capabilities and this isn’t a debate over those. I’m just looking forward to being able to use Zope’s admin interface (the ZMI) to go to the template I need to edit, hit command-control-E, and be able to edit it in a full featured native 100% Mac OS X editor.