Mention using ERBTracker with HAML in README

[nickurban]

My templates are all in HAML and it took me a while to figure out why my dependencies weren't being recognized and how to fix it.

I added an initializer, as suggested by @tim-vandecasteele in #45

Hopeful this will make it more clear to others.

[nickurban]

I made some assumptions about why this isn't automatically registered (i.e. that it's not officially supported). If I'm wrong about that, please correct me.

[tim-vandecasteele]

Maybe add a similar line for Slim

  # Or enable experimental Slim support with the ERB Dependency Tracker
  CacheDigests::DependencyTracker.register_tracker :slim, CacheDigests::DependencyTracker::ERBTracker

[nickurban]

Hey @tim-vandecasteele, I didn't add Slim because I haven't tested it myself.

Can you confirm that it works?

[tim-vandecasteele]

Yes, I confirm it's working for me. Dependencies are properly calculated when checking with the rake task.

[eprothro]

+1 for this PR. We lost a few hours that would have been saved by this being called out in the README.

[eprothro]

In case anyone is looking for the code for Haml (and other templating languages) support for view template cache digesting in Rails 4, it's referenced in this haml-rails PR: haml/haml-rails#50

Not trying to troll this post, but I think many may end up here if they're looking for how to get haml digestion to work in Rails as the code was ported from this repo.

[austenito]

+1 for this. Spent some time trying to configure cache_digests and didn't figure out what was up until I check the source.

[eprothro]

FYI, @austenito if you're using the latest haml-rails release, it includes the necessary code to ensure cache digesting works properly.

[austenito]

@eprothro thanks I'll give that a shot!

[eprothro]

@austenito no problem! Please let us know over on haml-rails if you have issues.

[jjb]

update: https://github.com/indirect/haml-rails/ will now automagically include the initializer code. so if you are using rails you can just put haml-rails in your gemfile and this is taken care of.