FEATURE: Let plugins register themes easily

app/assets/javascripts/discourse/templates/application.hbs

@@ -20,11 +20,11 @@
   {{outlet "user-card"}}
 </div>
 
-{{plugin-outlet name="above-footer"}}
+{{plugin-outlet name="above-footer" args=(hash showFooter=showFooter)}}
 {{#if showFooter}}
   {{custom-html name="footer"}}
 {{/if}}
-{{plugin-outlet name="below-footer"}}
+{{plugin-outlet name="below-footer" args=(hash showFooter=showFooter)}}
 
 {{outlet "modal"}}
 {{topic-entrance}}

app/models/color_scheme.rb

@@ -92,15 +92,21 @@ class ColorScheme < ActiveRecord::Base
     new_color_scheme
   end
 
-  def self.hex_for_name(name)
-    val = begin
-      hex_cache[name] ||= begin
-        # Can't use `where` here because base doesn't allow it
-        (enabled || base).colors.find {|c| c.name == name }.try(:hex) || :nil
+  def self.lookup_hex_for_name(name)
+    Discourse.plugin_themes.each do |pt|
+      if pt.color_scheme
+        found = pt.color_scheme[name.to_sym]
+        return found if found
       end
     end
 
-    val == :nil ? nil : val
+    # Can't use `where` here because base doesn't allow it
+    (enabled || base).colors.find {|c| c.name == name }.try(:hex) || :nil
+  end
+
+  def self.hex_for_name(name)
+    hex_cache[name] ||= lookup_hex_for_name(name)
+    hex_cache[name] == :nil ? nil : hex_cache[name]
   end
 
   def colors=(arr)

lib/discourse.rb

@@ -121,6 +121,10 @@ module Discourse
     @plugins ||= []
   end
 
+  def self.plugin_themes
+    @plugin_themes ||= plugins.map(&:themes).flatten
+  end
+
   def self.official_plugins
     plugins.find_all{|p| p.metadata.official?}
   end

lib/plugin/instance.rb

@@ -2,6 +2,7 @@ require 'digest/sha1'
 require 'fileutils'
 require_dependency 'plugin/metadata'
 require_dependency 'plugin/auth_provider'
+require_dependency 'plugin/theme'
 
 class Plugin::CustomEmoji
   def self.cache_key
@@ -24,7 +25,13 @@ class Plugin::Instance
   attr_reader :admin_route
 
   # Memoized array readers
-  [:assets, :auth_providers, :color_schemes, :initializers, :javascripts, :styles].each do |att|
+  [:assets,
+   :auth_providers,
+   :color_schemes,
+   :initializers,
+   :javascripts,
+   :styles,
+   :themes].each do |att|
     class_eval %Q{
       def #{att}
         @#{att} ||= []
@@ -173,6 +180,10 @@ class Plugin::Instance
     end
   end
 
+  def directory
+    File.dirname(path)
+  end
+
   def auto_generated_path
     File.dirname(path) << "/auto_generated"
   end
@@ -244,6 +255,19 @@ class Plugin::Instance
     Plugin::CustomEmoji.register(name, url)
   end
 
+  def register_theme(name)
+    return unless enabled?
+
+    theme = Plugin::Theme.new(self, name)
+    yield theme
+    themes << theme
+  end
+
+  # def register_public
+  #   return unless enabled?
+  #
+  # end
+
   def automatic_assets
     css = styles.join("\n")
     js = javascripts.join("\n")

lib/plugin/theme.rb

@@ -0,0 +1,32 @@
+class Plugin::Theme
+  attr_reader :color_scheme
+
+  def initialize(plugin, name)
+    @plugin = plugin
+    @name = name
+  end
+
+  def css(name)
+    @plugin.register_asset("stylesheets/#{name}.scss")
+  end
+
+  def set_color_scheme(scheme)
+    @color_scheme = scheme
+  end
+
+  def register_public
+    public_dir = "#{@plugin.directory}/public"
+    if File.exist?(public_dir)
+      if Rails.env.development?
+        Rails.application.config.before_initialize do |app|
+          app.middleware.insert_before(
+            ::ActionDispatch::Static,
+            ::ActionDispatch::Static,
+            public_dir
+          )
+        end
+      end
+    end
+  end
+end
+

lib/sass/discourse_sass_importer.rb

@@ -41,15 +41,9 @@ class DiscourseSassImporter < Sass::Importers::Filesystem
         case name
         when "theme_variables"
           contents = ""
-          if color_scheme = ColorScheme.enabled
-            ColorScheme.base_colors.each do |n, base_hex|
-              override = color_scheme.colors_by_name[n]
-              contents << "$#{n}: ##{override ? override.hex : base_hex} !default;\n"
-            end
-          else
-            special_imports[name].each do |css_file|
-              contents << File.read(css_file)
-            end
+          ColorScheme.base_colors.each do |n, base_hex|
+            hex_val = ColorScheme.hex_for_name(n) || base_hex
+            contents << "$#{n}: ##{hex_val} !default;\n"
           end
         when "category_backgrounds"
           contents = ""

spec/components/plugin/instance_spec.rb

@@ -160,6 +160,27 @@ describe Plugin::Instance do
     end
   end
 
+  context "themes" do
+    it "can register a theme" do
+      plugin = Plugin::Instance.new nil, "/tmp/test.rb"
+      plugin.register_theme('plugin') do |theme|
+        theme.set_color_scheme(
+          primary: 'ffff00',
+          secondary: '222222',
+          tertiary: '0f82af',
+          quaternary: 'c14924',
+          header_background: '111111',
+          header_primary: '333333',
+          highlight: 'a87137',
+          danger: 'e45735',
+          success: '1ca551',
+          love: 'fa6c8d'
+        )
+      end
+      expect(plugin.themes).to be_present
+    end
+  end
+
   context "register_color_scheme" do
     it "can add a color scheme for the first time" do
       plugin = Plugin::Instance.new nil, "/tmp/test.rb"
@@ -207,7 +228,7 @@ describe Plugin::Instance do
     it 'should add the right callback' do
       called = 0
 
-      method_name = plugin_instance.add_model_callback(User, :after_create) do
+      plugin_instance.add_model_callback(User, :after_create) do
         called += 1
       end
 
@@ -223,7 +244,7 @@ describe Plugin::Instance do
     it 'should add the right callback with options' do
       called = 0
 
-      method_name = plugin_instance.add_model_callback(User, :after_commit, on: :create) do
+      plugin_instance.add_model_callback(User, :after_commit, on: :create) do
         called += 1
       end