Code, games, and sarcasm
Matt Soucy

Implementing PrettyWeb

in code by Matt Soucy - Comments

In the process of implementing PrettyWeb, I ran into some issues.

The largest being Javascript. I wasn’t entirely comfortable with the language, and so my first few drafts of the addon were very rough. I frequently ran into issues where I didn’t understand Javascript’s syntax - for example, a foreach loop does NOT do what I expected it to. Nor do I have any idea what it DOES do. I also ran into issues where there’s no real “cross-platform” Javascript environment, the versions in web browsers are different than rhino, so I couldn’t even test anything without creating a web page - I’m used to being able to do everything in the CLI, so this was frustrating for me.

Firefox’s addon model was a bit odd at first, because I had to learn entirely new concepts like their XUL. I had some help by basing it off of Cloud-to-Butt, which does something like what I wanted to do - perform some filtering on the existing DOM. The difference between the two, though, is that Cloud-to-Butt works only on DOM “text nodes”, while I have more specific requirements - the “text nodes” within a <pre> tag directly below the <body> tag. This is because Firefox renders plain-text pages inside roughly the following structure:

  <link rel="alternate stylesheet" type="text/css" href="resource://gre-resources/plaintext.css" title="Wrap Long Lines">

Because I had the parser (stmd.js, which was renamed to commonmark.js while I was working on PrettyWeb), and I had the outline, the rest was just putting them together. I ran into problems when submitting to the Firefox Addon website, because CommonMark uses generated Javascript and a format that the Firefox developers don’t care for, so I’ll be attempting to fix those eventually.

The code is available on GitHub.