Posts tagged theme_support

Rails 2.3 final and theme_support updates

Mar 28th

Posted by James Stewart in Announcements

Somewhere between Ruby on Rails versions 2.3.0 (RC1) and 2.3.2 (final) a change was made to the arguments required for one of the methods the theme_support plugin requires. I must confess I hadn’t spotted it, but github user knapo kindly sent me a message with a patch. That patch is now applied in the main repository, as are a few tweaks to the ActionMailer integration to better handle multipart emails. You can get the new version from github.

Perhaps more significant than those small patches is that I’ve now pushed up a new rails app for use in testing theme_support. The tests are a series of cucumber stories, and the app is very barebones designed entirely to test the various features. I could do with tightening up the way the test app and the main plugin repository are connected, but it’s a start and has been very helpful with the aforementioned patches. Any improvements to the test suite would be much appreciated. You can, of course, find it on github.

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Rails 2.3 and theme_support part 3: Layouts

Feb 3rd

Posted by James Stewart in Notes

In my ongoing efforts to bring my fork of theme_support in line with Rails 2.3 I’ve covered the core views and email, but when I left off earlier today layouts still weren’t working.

The key problem with overriding layouts is that the process of identifying them relies on some class methods on ActionController::Base (provided in the ActionController::Layout module). Roughly put we have:

  1. ActionController::Base#render calls ActionController::Base#pick_layout
  2. ActionController::Base#pick_layout checks to see if there’s a specific layout requested and calls ActionController::Base#active_layout
  3. ActionController::Base#active_layout checks whether there’s a candidate layout for this controller or action and makes sure the layout exists by calling ActionController::Base.find_layout
  4. ActionController::Base.find_layout (class method) is called which checks the view_paths to find the appropriate layout in there

The issue is that as a class method ActionController::Base.active_layout has no knowledge of the specific controller instance, or the request object it contains, and so it can’t access our logic to determine the current theme.

One option would be to patch a number of these methods to hand a controller instance around which could be queried for the theme, but that seems rather clunky.

Another option is to wrap the active_layout method so that it (as an instance method) checks whether there is a current theme and if so, adds that theme’s path to the class level view_paths, removing it again after that check:

  class ActionController::Base
    alias_method :theme_support_active_layout, :active_layout
 
    def active_layout(passed_layout = nil)
      if current_theme
        theme_path = File.join(RAILS_ROOT, "themes", controller.current_theme, "views")
        if File.exists?(theme_path) and ! self.class.view_paths.include?(theme_path)
          self.class.view_paths.unshift(theme_path)
          result = theme_support_active_layout(passed_layout)
          self.class.view_paths.shift
          return result
        end
      end
 
      theme_support_active_layout(passed_layout)
    end
  end

And it works!

So that’s views, emails and now layouts all working with theme_support on Rails 2.3. As before, you can get the results in the branch on github:

http://github.com/jystewart/theme_support/tree/rails-2-3-support

Over the next couple of weeks I’m hoping to test my patches on other releases in the 2.x series, probably using a test app with specs or stories that will put it through its paces. Once that’s done I may turn my attention to the other corners of the plugin (that I don’t personally use) like the asset helper methods, but if anyone wants to contribute patches in the meantime I’d love to get them.

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Rails 2.3 and theme_support part 2: ActionMailer

Feb 3rd

Posted by James Stewart in Notes

Stage 2 of fixing up theme_support for Rails 2.3 was making sure that ActionMailer picked up themed templates (for stage 1 information see here). That’s something I’d not quite cracked in the 2.2 version, so starting afresh with 2.3 forced me to spend the time to look through the full render path and figure out what was going on.

ActionMailer is a little more complicated than ActionView in that there are multiple routes of entry (ways of sending emails) and each email can have multiple templates associated with it to allow for multipart email. But at the core of it all is the ActionMailer::Base#create! method. This executes the specific method that populates the mailer variables (ie. the code you actually write in your mailers) and then uses Dir.glob to look for appropriate templates for this email:

Dir.glob("#{template_path}/#{@template}.*").each do |path|
  template = template_root["#{template_path}/#{File.basename(path)}"]
 
  # Skip unless template has a multipart format
  next unless template && template.multipart?
 
  @parts < < Part.new(
    :content_type => template.content_type,
    :disposition => "inline",
    :charset => charset,
    :body => render_message(template, @body)
  )
end

The initial patch provides a couple of ways to specify the theme for an email. I’m mainly using the approach of specifying self.current_theme within a mailer method. eg:

class UserMailer < ActionMailer::Base
  def activation(user)
    setup_email(user)
    self.current_theme = user.site.theme
    @subject    += 'Your account has been activated!'
    @body[:url]  = "http://www.catapultmagazine.com/"
  end
end

With that in place the next step was to patch ActionMailer::Base#create! so that instead of just looking at the main template_path it looked first in the relevant theme folder and then in the main template folder. So the code above becomes:

tpaths = []
tpaths < < File.join(RAILS_ROOT, "themes", self.current_theme, "views", mailer_name) if self.current_theme
tpaths << template_path
 
tpaths.each do |tpath|
  Dir.glob("#{tpath}/#{@template}.*").each do |path|
    template = template_root["#{tpath}/#{File.basename(path)}"]
 
    # Skip unless template has a multipart format
    next unless template && template.multipart?
 
    @parts << Part.new(
      :content_type => template.content_type,
      :disposition => "inline",
      :charset => charset,
      :body => render_message(template, @body)
    )
  end
  break if @parts.any?
end

The keen-eyed among you will notice that this means you can't have, say, your HTML part themed and your plain text part in your main app/views folder. There would be ways around that, but this seemed the cleanest approach to take.

UPDATE (5pm): I've now got layouts working too. More on that over here.

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Rails 2.3 and theme_support

Feb 2nd

Posted by James Stewart in Notes

A couple of months back, I realised that two of my projects (Generous and Catapult) could do with the help of the theme_support Rails plugin. Discovering that it didn’t play nicely with Rails 2.1, I created a fork on github and hacked at the _pick_template method to get it to do what I wanted. It turned out a few people were interested in having the plugin work with Rails 2.1, some of whom used more of the plugin’s featured than I need, and a few further forks emerged. I’ve been meaning to work through them and merge together the best bits, but the impending release of Rails 2.3 stopped me in my tracks.

I’m particularly keen to upgrade to 2.3 because Catapult generates a lot of routes and 2.3’s improved route handling should save us quite a bit of RAM and a number of cycles. So it was rather frustrating to find that yet again a new release of rails broke the plugin. Many hours later, working my way through the render path and trying to find the optimal solution, I’m not quite there, but it sort of works and seemed worth writing up:

It turns out that for most templates there’s a single point we can patch that will handle things. ActionView::Base#view_paths returns an instance of ActionView::PathSet which is an augmented Array that ActionView consults to find a template that matches its current requirements. By overriding that method we can check to see if a theme should be active and add that theme’s folder to the set of paths to be consulted.

module ActionView
  class Base
 
    alias_method :theme_support_old_view_paths, :view_paths
 
    def view_paths
      paths = theme_support_old_view_paths
 
      if controller and controller.current_theme
        theme_path = File.join(RAILS_ROOT, "themes", controller.current_theme, "views")
        if File.exists?(theme_path) and ! paths.include?(theme_path)
          paths.unshift(theme_path)
        end
      end
 
      paths
    end
  end
end

The hitch is that this doesn’t work for layouts, which take a slightly different path. In my case, that’s not a huge deal, but it’s a major omission for other uses. I’ve also not yet tested the actionmailer handling.

You can track progress in a branch on GitHub. I’ll post here as I make more progress, but would welcome any contributions from the rest of the community.

UPDATE (10pm): I just checked in ActionMailer support. More on that tomorrow.

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