I wanted to find a way to do syntax highlighting of code snippets on my Drupal blog. I came across the GeSHi Filter module, which lets Drupal sites take advantage of the apparently well-regarded GeSHi Generic Syntax Highlighter library that’s meant for just this purpose.
However, I ran into some roadblocks implementing it on my site. Here’s the short story of what I settled on after some trial and error.
My existing code snippets are in <code> blocks, and the initial GeSHi Filter settings applied badly to them. I made the decision to only use GeSHi on <blockcode> blocks, since I wasn’t using that tag yet and it wouldn’t conflict with the snippets already posted.
I most commonly write Bash/Zsh, Python, and AppleScript snippets on my blog. However, the Bash code I was using as part of my trial and error simply wasn’t highlighting; it was coming through as the default (and boring) plain text — but was at least boxed off from the rest of the blog post.
I thought that GeSHi wasn’t correctly discovering that the code was written in UNIX shell syntax. I couldn’t find a way to specify the language for that blockcode tag, until I did some searching on the ’net. To change my blockquotes to choose a certain language — at least for the purposes of this Drupal module, if not for GeSHI in general — I needed to add the “lang=lang” style to the tag. For Bash, I could use “lang=bash,” for Python, “lang=python,” and for AppleScript, “lang=applescript.” That made sense.
However, my code was still not being syntax highlighted. I discovered that the Drupal module came with an initial set of languages enabled. The others were all turned off, but that could be changed in the module settings. Without turning them on, even properly-tagged <blockcode> sections did not get the benefit of syntax highlighting.
I changed the GeSHi Filter options to enable some of the languages that were initially disabled, and then disabled the ones I didn’t anticipate using. This allowed me to add Bash and AppleScript syntax highlighting support, as both had been turned off by default. After that, I saw the results I’d hoped for: a syntax-highlighted code snippet.
It took some work, but now that it’s done, I should be all set.
