From d22eb7d0b08a197c0315b6224f50ab23983ebed5 Mon Sep 17 00:00:00 2001
From: Tim Felgentreff <timfelgentreff@gmail.com>
Date: Tue, 7 Sep 2010 19:59:21 +0200
Subject: [PATCH] Add a Redmine plugin locator to be able to query the rails plugin search
 path for dependencies when loading redmine plugins

---
 config/environment.rb         |    4 +++
 lib/redmine/plugin.rb         |   52 ++++++++++++++++++++++++++++++++--------
 lib/redmine_plugin_locator.rb |   22 +++++++++++++++++
 3 files changed, 67 insertions(+), 11 deletions(-)
 create mode 100644 lib/redmine_plugin_locator.rb

diff --git a/config/environment.rb b/config/environment.rb
index 97fc54a..891f407 100644
--- a/config/environment.rb
+++ b/config/environment.rb
@@ -50,6 +50,10 @@ Rails::Initializer.run do |config|
   # It will automatically turn deliveries on
   config.action_mailer.perform_deliveries = false
 
+  # Use redmine's custom plugin locater
+  require File.join(RAILS_ROOT, "lib/redmine_plugin_locator")
+  config.plugin_locators << RedminePluginLocator
+
   config.gem 'rubytree', :lib => 'tree'
   
   # Load any local configuration that is kept out of source control
diff --git a/lib/redmine/plugin.rb b/lib/redmine/plugin.rb
index 2be8ac8..2f3aadc 100644
--- a/lib/redmine/plugin.rb
+++ b/lib/redmine/plugin.rb
@@ -17,7 +17,13 @@
 
 module Redmine #:nodoc:
 
-  class PluginNotFound < StandardError; end
+  class PluginNotFound < StandardError
+    attr_reader :plugin_id
+    def initialize(plug_id=nil)
+      super
+      @plugin_id = plug_id
+    end
+  end
   class PluginRequirementError < StandardError; end
   
   # Base class for Redmine plugins.
@@ -44,8 +50,10 @@ module Redmine #:nodoc:
   # When rendered, the plugin settings value is available as the local variable +settings+
   class Plugin
     @registered_plugins = {}
+    @deferred_plugins   = {}
+
     class << self
-      attr_reader :registered_plugins
+      attr_reader :registered_plugins, :deferred_plugins
       private :new
 
       def def_field(*names)
@@ -63,14 +71,36 @@ module Redmine #:nodoc:
     
     # Plugin constructor
     def self.register(id, &block)
-      p = new(id)
-      p.instance_eval(&block)
-      # Set a default name if it was not provided during registration
-      p.name(id.to_s.humanize) if p.name.nil?
-      # Adds plugin locales if any
-      # YAML translation files should be found under <plugin>/config/locales/
-      ::I18n.load_path += Dir.glob(File.join(RAILS_ROOT, 'vendor', 'plugins', id.to_s, 'config', 'locales', '*.yml'))
-      registered_plugins[id] = p
+      begin
+        id = id.to_sym
+        p = new(id)
+        p.instance_eval(&block)
+        # Set a default name if it was not provided during registration
+        p.name(id.to_s.humanize) if p.name.nil?
+        # Adds plugin locales if any
+        # YAML translation files should be found under <plugin>/config/locales/
+        ::I18n.load_path += Dir.glob(File.join(RAILS_ROOT, 'vendor', 'plugins', id.to_s, 'config', 'locales', '*.yml'))
+        registered_plugins[id] = p
+
+        # If there are plugins waiting for us to be loaded, we try loading those, again
+        if deferred_plugins[id]
+          deferred_plugins[id].each do |ary|
+            plugin_id, block = ary
+            register(plugin_id, &block)
+          end
+          deferred_plugins.delete(id)
+        end
+
+        return p
+      rescue PluginNotFound => e
+        if RedminePluginLocator.instance.has_plugin? e.plugin_id
+          # The required plugin is going to be loaded later, defer loading this plugin
+          (deferred_plugins[e.plugin_id] ||= []) << [id, block]
+          return p
+        else
+          raise e
+        end
+      end
     end
     
     # Returns an array off all registered plugins
@@ -81,7 +111,7 @@ module Redmine #:nodoc:
     # Finds a plugin by its id
     # Returns a PluginNotFound exception if the plugin doesn't exist
     def self.find(id)
-      registered_plugins[id.to_sym] || raise(PluginNotFound)
+      registered_plugins[id.to_sym] || raise(PluginNotFound.new(id.to_sym))
     end
     
     # Clears the registered plugins hash
diff --git a/lib/redmine_plugin_locator.rb b/lib/redmine_plugin_locator.rb
new file mode 100644
index 0000000..28ffcd8
--- /dev/null
+++ b/lib/redmine_plugin_locator.rb
@@ -0,0 +1,22 @@
+class RedminePluginLocator < Rails::Plugin::FileSystemLocator
+  def initialize(initializer)
+    super
+    @@instance = self
+  end
+
+  def self.instance
+    @@instance
+  end
+
+  # This locator is not meant for loading plugins
+  # The plugin loading is done by the default rails locator, this one is
+  # only for querying available plugins easily
+  def plugins(for_loading = true)
+    return [] if for_loading
+    super()
+  end
+
+  def has_plugin?(name)
+    plugins(false).collect(&:name).include? name.to_s
+  end
+end
-- 
1.7.2.3