rack-codehighlighter and nesta

[chikamichi]

Hi! I strive to plug rack-codehighlighter into nesta, but I did not manage to.

http://gist.github.com/264691 is an example of rack-codehighlighter used within a Sinatra app, without any haml layer. It works as expected (ruby test.rb, localhost:4567 -> the pre has been processed by ultraviolet). I tried to do the same in nesta, but nothing gets processed. I tried to add the haml processing step to my simple test.rb, did not succeed :) So I'll keep working on it, but if you have any hint on this…

[gma]

Hi. Sorry for the delay, I was a little busy there...

I'm having a bit of trouble getting ultraviolet installed on my Mac (though Coderay works fine). I don't think that will matter too much though, as the problem seems to be that new lines inside <pre/> tags are converted to the equivalent XHTML escape code (which is &#x000A;). I think these escape codes will be confusing rack-codehighlighter (and if it's actually Coderay that is getting confused – I've not dug into the source yet, there's a good chance that ultraviolet is too).

I'm not best sure how to sort this out yet. I'm going to go and get a coffee and collect my thoughts, but wanted to let you know that I'm on the case in the meantime.

Graham

[gma]

Okay, I think I've found a nice solution. The &#x000A; characters were getting inserted by HAML. From the HAML FAQ:

Because Haml automatically indents the HTML source code, the contents of whitespace-sensitive tags like +pre+ and +textarea+ can get screwed up. The solution is to replace the newlines inside these tags with HTML newline entities (&#x000A;), ...

I did some tests and verified that the 
 codes were confusing both rack-codehighlighter and Coderay. It was fairly easy to patch rack-codehighlighter so that it treated 
 as a new line character, and I've commited a patch to my rack-codehighlighter fork on GitHub:

• http://github.com/gma/rack-codehighlighter/commit/21d1b80270da794e93a64c28ddec5b152bdb2b27

We'll have to see what Wlodek makes of it; he may have a better solution up his sleeve, or feel that the fix doesn't belong in rack-codehighlighter.

Anyway, I suspect that anybody else who wants to use rack-codehighlighter with HTML rendered by HAML will run into similar problems. They certainly will if they use HAML's ~ command to insert HTML into a template with whitespace preserved, which is what Nesta is doing in the page.haml file.

Note that my patch to rack-codehighlighter changes the default regex, so you will either need to update your :pattern => /.../ code, or remove it so that the default is used.

This was all I needed to get Coderay working:

require "coderay"
require "rack/codehighlighter"

use Rack::Codehighlighter, :coderay, :element => "pre>code", :markdown => true

I created a local directory in my top level Nesta directory and added put that code in local/app.rb. It's loaded automatically if it exists, which means that you won't have to worry about merge conflicts in future if I add some similar code. Alternatively config.ru would be a good place to put it.

Also bear in mind that because Nesta's file caching writes files to public/ that your web server may bypass Rack/Sinatra entirely and just serve the file off disk. I've got Nginx configured to behave like this on my sites. If this is the case the codehighlighter middleware won't get a chance to modify the HTML. HTTP caching (i.e. Rack::Cache) would be a good way to fix this; it's on the todo list...

Hope this has helped. Sorry it took me a few days to get to it.

Cheers, Graham

[chikamichi]

Hi. I'm glad you fixed the issue so quickly and were kind enough to write this very clear explanation! I've been quite busy lately so I did not tried to get it working on my side, but I'll sure be able to hack on it within the next few days.

[gma]

Wlodek has sent me a message to say that the patch has been pulled into rack-codehighlighter, and that he's pushed the latest gem (0.4.1) to gemcutter. I suspect that a quick gem update should get it all working...