1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
require 'rails/railtie'
require 'active_support/core_ext/module/delegation'
require 'pathname'
module Rails
# Rails::Engine allows you to wrap a specific Rails application and share it accross
# different applications. Since Rails 3.0, every Rails::Application is nothing
# more than an Engine, allowing you to share it very easily.
#
# Any Rails::Engine is also a Rails::Railtie, so the same methods (like rake_tasks and
# generators) and configuration available in the latter can also be used in the former.
#
# == Creating an Engine
#
# In Rails versions before to 3.0, your gems automatically behaved as Engine, however
# this coupled Rails to Rubygems. Since Rails 3.0, if you want a gem to automatically
# behave as Engine, you have to specify an Engine for it somewhere inside your plugin
# lib folder (similar with how we spceify a Railtie):
#
# # lib/my_engine.rb
# module MyEngine
# class Engine < Rails::Engine
# end
# end
#
# Then ensure that this file is loaded at the top of your config/application.rb (or in
# your Gemfile) and it will automatically load models, controllers, helpers and metals
# inside app, load routes at "config/routes.rb", load locales at "config/locales/*",
# load tasks at "lib/tasks/*".
#
# == Configuration
#
# Besides the Railtie configuration which is shared across the application, in a
# Rails::Engine you can access load_paths, eager_load_paths and load_once_paths,
# which differently from a Railtie, are scoped to the current Engine.
#
# Example:
#
# class MyEngine < Rails::Engine
# # Add a load path for this specific Engine
# config.load_paths << File.expand_path("../lib/some/path", __FILE__)
#
# initializer "my_engine.add_middleware" do |app|
# app.middlewares.use MyEngine::Middleware
# end
# end
#
# == Paths
#
# Since Rails 3.0, both your Application and Engines do not have hardcoded paths.
# This means that you are not required to place your controllers at "app/controllers",
# but in any place which you find convenient.
#
# For example, let's suppose you want to lay your controllers at lib/controllers, all
# you need to do is:
#
# class MyEngine < Rails::Engine
# paths.app.controllers = "lib/controllers"
# end
#
# You can also have your controllers being loaded from both "app/controllers" and
# "lib/controllers":
#
# class MyEngine < Rails::Engine
# paths.app.controllers << "lib/controllers"
# end
#
# The available paths in an Engine are:
#
# class MyEngine < Rails::Engine
# paths.app = "app"
# paths.app.controllers = "app/controllers"
# paths.app.helpers = "app/helpers"
# paths.app.models = "app/models"
# paths.app.metals = "app/metal"
# paths.app.views = "app/views"
# paths.lib = "lib"
# paths.lib.tasks = "lib/tasks"
# paths.config = "config"
# paths.config.initializers = "config/initializers"
# paths.config.locales = "config/locales"
# paths.config.routes = "config/routes.rb"
# end
#
# Your Application class adds a couple more paths to this set. And as in your Application,
# all folders under "app" are automatically added to the load path. So if you have
# "app/observers", it's added by default.
#
class Engine < Railtie
autoload :Configurable, "rails/engine/configurable"
autoload :Configuration, "rails/engine/configuration"
class << self
attr_accessor :called_from
# TODO Remove this. It's deprecated.
alias :engine_name :railtie_name
def inherited(base)
unless base.abstract_railtie?
base.called_from = begin
# Remove the line number from backtraces making sure we don't leave anything behind
call_stack = caller.map { |p| p.split(':')[0..-2].join(':') }
File.dirname(call_stack.detect { |p| p !~ %r[railties[\w\-\.]*/lib/rails|rack[\w\-\.]*/lib/rack] })
end
end
super
end
def find_root_with_flag(flag, default=nil)
root_path = self.called_from
while root_path && File.directory?(root_path) && !File.exist?("#{root_path}/#{flag}")
parent = File.dirname(root_path)
root_path = parent != root_path && parent
end
root = File.exist?("#{root_path}/#{flag}") ? root_path : default
raise "Could not find root path for #{self}" unless root
RUBY_PLATFORM =~ /(:?mswin|mingw)/ ?
Pathname.new(root).expand_path : Pathname.new(root).realpath
end
end
delegate :middleware, :paths, :root, :to => :config
def load_tasks
super
config.paths.lib.tasks.to_a.sort.each { |ext| load(ext) }
end
# Add configured load paths to ruby load paths and remove duplicates.
initializer :set_load_path, :before => :bootstrap_load_path do
config.load_paths.reverse_each do |path|
$LOAD_PATH.unshift(path) if File.directory?(path)
end
$LOAD_PATH.uniq!
end
# Set the paths from which Rails will automatically load source files,
# and the load_once paths.
initializer :set_autoload_paths, :before => :bootstrap_load_path do |app|
ActiveSupport::Dependencies.load_paths.unshift(*config.load_paths)
if reloadable?(app)
ActiveSupport::Dependencies.load_once_paths.unshift(*config.load_once_paths)
else
ActiveSupport::Dependencies.load_once_paths.unshift(*config.load_paths)
end
# Freeze so future modifications will fail rather than do nothing mysteriously
config.load_paths.freeze
config.load_once_paths.freeze
end
initializer :add_routing_paths do |app|
paths.config.routes.to_a.each do |route|
app.routes_reloader.paths.unshift(route) if File.exists?(route)
end
end
# DEPRECATED: Remove in 3.1
initializer :add_routing_namespaces do |app|
paths.app.controllers.to_a.each do |load_path|
load_path = File.expand_path(load_path)
Dir["#{load_path}/*/**/*_controller.rb"].collect do |path|
namespace = File.dirname(path).sub(/#{load_path}\/?/, '')
app.routes.controller_namespaces << namespace unless namespace.empty?
end
end
end
# I18n load paths are a special case since the ones added
# later have higher priority.
initializer :add_locales do
config.i18n.railties_load_path.concat(paths.config.locales.to_a)
end
initializer :add_view_paths do
views = paths.app.views.to_a
ActiveSupport.on_load(:action_controller) do
prepend_view_path(views)
end
ActiveSupport.on_load(:action_mailer) do
prepend_view_path(views)
end
end
initializer :add_metals do |app|
app.metal_loader.paths.unshift(*paths.app.metals.to_a)
end
initializer :load_config_initializers do
paths.config.initializers.to_a.sort.each do |initializer|
load(initializer)
end
end
initializer :load_app_classes do |app|
next if $rails_rake_task
if app.config.cache_classes
config.eager_load_paths.each do |load_path|
matcher = /\A#{Regexp.escape(load_path)}\/(.*)\.rb\Z/
Dir.glob("#{load_path}/**/*.rb").sort.each do |file|
require_dependency file.sub(matcher, '\1')
end
end
end
end
protected
def reloadable?(app)
app.config.reload_engines
end
end
end
|
