diff --git a/hooks/app/views/layouts/base.rhtml b/hooks/app/views/layouts/base.rhtml
index 62d542b7b..5fe1c6135 100644
--- a/hooks/app/views/layouts/base.rhtml
+++ b/hooks/app/views/layouts/base.rhtml
@@ -14,8 +14,9 @@
body {behavior: url(<%= stylesheet_path "csshover.htc" %>);}
-
-<%= yield :header_tags %>
+<%= call_hook :view_layouts_base_html_head, :project => @project %>
+
+<%= yield :header_tags -%>
diff --git a/hooks/lib/redmine.rb b/hooks/lib/redmine.rb
index 9890ab06f..7e4365aef 100644
--- a/hooks/lib/redmine.rb
+++ b/hooks/lib/redmine.rb
@@ -4,6 +4,7 @@ require 'redmine/activity'
require 'redmine/mime_type'
require 'redmine/core_ext'
require 'redmine/themes'
+require 'redmine/hook'
require 'redmine/plugin'
begin
diff --git a/hooks/lib/redmine/hook.rb b/hooks/lib/redmine/hook.rb
new file mode 100644
index 000000000..fecdfed9a
--- /dev/null
+++ b/hooks/lib/redmine/hook.rb
@@ -0,0 +1,116 @@
+# Redmine - project management software
+# Copyright (C) 2006-2008 Jean-Philippe Lang
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+module Redmine
+ module Hook
+ HOOKS = %w(view_layouts_base_html_head).collect {|h| h.to_sym}
+
+ @@listener_classes = []
+ @@listeners = nil
+ @@hook_listeners = {}
+
+ class << self
+ # Adds a listener class.
+ # Automatically called when a class inherits from Redmine::Hook::Listener.
+ def add_listener(klass)
+ raise "Hooks must include Singleton module." unless klass.included_modules.include?(Singleton)
+ @@listener_classes << klass
+ clear_listeners_instances
+ end
+
+ # Returns all the listerners instances.
+ def listeners
+ @@listeners ||= @@listener_classes.collect {|listener| listener.instance}
+ end
+
+ # Returns the listeners instances for the given hook.
+ def hook_listeners(hook)
+ @@hook_listeners[hook] ||= listeners.select {|listener| listener.respond_to?(hook)}
+ end
+
+ # Clears all the listeners.
+ def clear_listeners
+ @@listener_classes = []
+ clear_listeners_instances
+ end
+
+ # Clears all the listeners instances.
+ def clear_listeners_instances
+ @@listeners = nil
+ @@hook_listeners = {}
+ end
+
+ # Calls a hook.
+ # Returns the listeners response.
+ def call_hook(hook, context={})
+ response = ''
+ hook_listeners(hook).each do |listener|
+ response << listener.send(hook, context).to_s
+ end
+ response
+ end
+
+ def hooks
+ HOOKS.dup
+ end
+
+ def valid_hook?(hook)
+ HOOKS.include?(hook)
+ end
+ end
+
+ # Base class for hook listeners.
+ class Listener
+ include Singleton
+
+ # Registers the listener
+ def self.inherited(child)
+ Redmine::Hook.add_listener(child)
+ super
+ end
+ end
+
+ # Listener class used for views hooks.
+ # Listeners that inherit this class will include various helpers by default.
+ class ViewListener < Listener
+ include ERB::Util
+ include ActionView::Helpers::TagHelper
+ include ActionView::Helpers::FormHelper
+ include ActionView::Helpers::FormTagHelper
+ include ActionView::Helpers::FormOptionsHelper
+ include ActionView::Helpers::JavaScriptHelper
+ include ActionView::Helpers::PrototypeHelper
+ include ActionView::Helpers::NumberHelper
+ include ActionView::Helpers::UrlHelper
+ include ActionController::UrlWriter
+ include ApplicationHelper
+ end
+
+ # Helper module included in ApplicationHelper so that hooks can be called
+ # in views like this:
+ # <%= call_hook(:some_hook) %>
+ # <%= call_hook(:another_hook, :foo => 'bar' %>
+ module Helper
+ def call_hook(hook, context={})
+ Redmine::Hook.call_hook(hook, context)
+ end
+ end
+ end
+end
+
+ApplicationHelper.send(:include, Redmine::Hook::Helper)
+
diff --git a/hooks/test/unit/lib/redmine/hook_test.rb b/hooks/test/unit/lib/redmine/hook_test.rb
new file mode 100644
index 000000000..31f289d0b
--- /dev/null
+++ b/hooks/test/unit/lib/redmine/hook_test.rb
@@ -0,0 +1,105 @@
+# redMine - project management software
+# Copyright (C) 2006-2008 Jean-Philippe Lang
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+
+require File.dirname(__FILE__) + '/../../../test_helper'
+
+class Redmine::Hook::ManagerTest < Test::Unit::TestCase
+
+ # Some fake hooks that are manually registered in these tests
+ class FakeHook
+ include Singleton
+ end
+
+ class TestHook1 < FakeHook
+ def view_layouts_base_html_head(context)
+ 'Test hook 1 listener.'
+ end
+ end
+
+ class TestHook2 < FakeHook
+ def view_layouts_base_html_head(context)
+ 'Test hook 2 listener.'
+ end
+ end
+
+ class TestHook3 < FakeHook
+ def view_layouts_base_html_head(context)
+ "Context keys: #{context.keys.collect(&:to_s).sort.join(', ')}."
+ end
+ end
+
+ def setup
+ @hook_module = Redmine::Hook
+ end
+
+ def teardown
+ @hook_module.clear_listeners
+ end
+
+ def test_sanity
+ assert true
+ end
+
+ def test_hooks_format
+ assert_kind_of Array, @hook_module.hooks
+ @hook_module.hooks.each do |hook|
+ assert_kind_of Symbol, hook
+ assert_kind_of Array, @hook_module.hook_listeners(hook)
+ assert_equal 0, @hook_module.hook_listeners(hook).length
+ end
+ end
+
+ def test_valid_hook
+ assert @hook_module.valid_hook?(:view_layouts_base_html_head)
+ end
+
+ def test_invalid_hook
+ assert !@hook_module.valid_hook?(:an_invalid_hook_name)
+ end
+
+ def test_clear_listeners
+ assert_equal 0, @hook_module.hook_listeners(:view_layouts_base_html_head).size
+ @hook_module.add_listener(TestHook1)
+ @hook_module.add_listener(TestHook2)
+ assert_equal 2, @hook_module.hook_listeners(:view_layouts_base_html_head).size
+
+ @hook_module.clear_listeners
+ assert_equal 0, @hook_module.hook_listeners(:view_layouts_base_html_head).size
+ end
+
+ def test_add_listener
+ assert_equal 0, @hook_module.hook_listeners(:view_layouts_base_html_head).size
+ @hook_module.add_listener(TestHook1)
+ assert_equal 1, @hook_module.hook_listeners(:view_layouts_base_html_head).size
+ end
+
+ def test_call_hook
+ @hook_module.add_listener(TestHook1)
+ assert_equal 'Test hook 1 listener.', @hook_module.call_hook(:view_layouts_base_html_head)
+ end
+
+ def test_call_hook_with_context
+ @hook_module.add_listener(TestHook3)
+ assert_equal 'Context keys: bar, foo.', @hook_module.call_hook(:view_layouts_base_html_head, :foo => 1, :bar => 'a')
+ end
+
+ def test_call_hook_with_multiple_listeners
+ @hook_module.add_listener(TestHook1)
+ @hook_module.add_listener(TestHook2)
+ assert_equal 'Test hook 1 listener.Test hook 2 listener.', @hook_module.call_hook(:view_layouts_base_html_head)
+ end
+end