Force usage of hamlit in Rails when haml gem is also bundled?

[bensheldon]

I'm in the situation where I am trying to use hamlit in my Rails application, but unfortunately I have a Gemfile dependency on rails_admin, which has a dependency on the original haml gem. With both haml and hamlit bundled, it seems like the original haml gem wins out. Is there a way that I can force Rails to use hamlit and not haml when rendering templates?

Thanks for the help.

[k0kubun]

Thank you for reporting an issue. I could reproduce your environment and resolve it.
Could you try to put following code in config/initializers/hamlit.rb?

# config/initializers/hamlit.rb
module Hamlit
  class TemplateHandler
    def call(template)
      Engine.new(
        generator: Temple::Generators::RailsOutputBuffer,
        filename: template.identifier,
      ).call(template.source)
    end
  end
end

ActionView::Template.register_template_handler(
  :haml,
  Hamlit::TemplateHandler.new,
)

I think Hamlit should overwrite Haml by default. I'll fix it later.

[bensheldon]

Thanks for the quick help! In exploring the problem further, I think I may have been mistaken about hamlit not being mounted in the presence of haml in bundle. In doing further profiling, it seems like haml monkeypatches in ActionView#render_with_haml which gets called even if the template itself is being rendered by hamlit. This was confusing me. Here is a portion of my callstack:

...
… actionview-4.2.2/lib/action_view/renderer/renderer.rb:46:in `ActionView::Renderer#render_partial'   (147 samples - 48.36%)
… actionview-4.2.2/lib/action_view/renderer/renderer.rb:19:in `ActionView::Renderer#render'   (267 samples - 87.83%)
… actionview-4.2.2/lib/action_view/helpers/rendering_helper.rb:26:in `ActionView::Helpers::RenderingHelper#render'    (263 samples - 86.51%)
… haml-4.0.6/lib/haml/helpers/action_view_mods.rb:3:in `ActionView::Base#render_with_haml'    (263 samples - 86.51%)
/Users/bensheldon/Workspace/dayoftheshirt-rails/app/views/shirts/index.html.haml::in `ActionView::CompiledTemplates#_app_views_shirts_index_html_haml___1478955222455656801_2252899580' (124 samples - 40.79%)
… actionview-4.2.2/lib/action_view/template.rb:143:in `block in ActionView::Template#render'  (264 samples - 86.84%)
...

But when looking at what is actually rendering the template, it was hamlit (I did this by looking at where the most memory allocations were, not sure if there is a better way to introspect)... even without the snippets you provided. So I think there was never a problem in the first place in regards to rendering (but for some reason haml feels it necessary to monkeypatch in that method).

Also, the snippet you pasted I had a typo I think. There is not a template option Hamlit::Engine. This is snippet that worked for me (though ended up being unnecessary).

# config/initializers/hamlit.rb
module Hamlit
  class TemplateHandler
    def call(template)
      Engine.new(
        generator: Temple::Generators::RailsOutputBuffer,
        attr_quote: '"',
      ).call(template.source)
    end
  end
end

ActionView::Template.register_template_handler(
  :haml,
  Hamlit::TemplateHandler.new,
)

Thank you again!

Edit: Also wanted to add that I'm seeing 20% faster page loads and 20% less memory usage in switching to Hamlit. Which is awesome!

[k0kubun]

not sure if there is a better way to introspect

Hamlit test cases generate incompatibilities against Haml. You can check which template engine is used with them. https://github.com/k0kubun/hamlit/tree/39b4634a3e1e3de529cda01c380c33b9fa54378f/doc/haml

Also, the snippet you pasted I had a typo I think. There is not a template option Hamlit::Engine.

🙇

Thank you again!
Edit: Also wanted to add that I'm seeing 20% faster page loads and 20% less memory usage in switching to Hamlit. Which is awesome!

Thank you for using hamlit. :)

[connorshea]

I'm running into this same issue, how can I tell for sure that Hamlit is being used and not Haml?

[k0kubun]

Didn't #30 (comment) work for you?

If it didn't, please try to put require 'haml' before Bundler.require(*Rails.groups) in config/application.rb.