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
|
unless Object.respond_to?(:require_dependency)
Object.send(:define_method, :require_dependency) { |file_name| ActionController::Base.require_dependency(file_name) }
end
module ActionController #:nodoc:
module Dependencies #:nodoc:
def self.append_features(base)
super
base.class_eval do
# When turned on (which is default), all dependencies are included using "load". This mean that any change is instant in cached
# environments like mod_ruby or FastCGI. When set to false, "require" is used, which is faster but requires server restart to
# be effective.
@@reload_dependencies = true
cattr_accessor :reload_dependencies
end
base.class_eval { class << self; alias_method :inherited_without_model, :inherited; end }
base.extend(ClassMethods)
end
# Dependencies control what classes are needed for the controller to run its course. This is an alternative to doing explicit
# +require+ statements that bring a number of benefits. It's more succinct, communicates what type of dependency we're talking about,
# can trigger special behavior (as in the case of +observer+), and enables Rails to be clever about reloading in cached environments
# like FCGI. Example:
#
# class ApplicationController < ActionController::Base
# model :account, :company, :person, :project, :category
# helper :access_control
# service :notifications, :billings
# observer :project_change_observer
# end
#
# Please note that a controller like ApplicationController will automatically attempt to require_dependency on a model of its
# singuralized name and a helper of its name. If nothing is found, no error is raised. This is especially useful for concrete
# controllers like PostController:
#
# class PostController < ApplicationController
# # model :post (already required)
# # helper :post (already required)
# end
module ClassMethods
# Loads the <tt>file_name</tt> if reload_dependencies is true or requires if it's false.
def require_dependency(file_name)
reload_dependencies ? silence_warnings { load("#{file_name}.rb") } : require(file_name)
end
# Specifies a variable number of models that this controller depends on. Models are normally Active Record classes or a similar
# backend for modelling entity classes.
def model(*models)
require_dependencies(:model, models)
depend_on(:model, models)
end
# Specifies a variable number of services that this controller depends on. Services are normally singletons or factories, like
# Action Mailer service or a Payment Gateway service.
def service(*services)
require_dependencies(:service, services)
depend_on(:service, services)
end
# Specifies a variable number of observers that are to govern when this controller is handling actions. The observers will
# automatically have .instance called on them to make them active on assignment.
def observer(*observers)
require_dependencies(:observer, observers)
depend_on(:observer, observers)
instantiate_observers(observers)
end
# Returns an array of symbols that specify the dependencies on a given layer. For the example at the top, calling
# <tt>ApplicationController.dependencies_on(:model)</tt> would return <tt>[:account, :company, :person, :project, :category]</tt>
def dependencies_on(layer)
read_inheritable_attribute("#{layer}_dependencies")
end
def depend_on(layer, dependencies) #:nodoc:
write_inheritable_array("#{layer}_dependencies", dependencies)
end
private
def instantiate_observers(observers)
observers.flatten.each { |observer| Object.const_get(Inflector.classify(observer.to_s)).instance }
end
def require_dependencies(layer, dependencies)
dependencies.flatten.each do |dependency|
begin
require_dependency(dependency.to_s)
rescue LoadError
raise LoadError, "Missing #{layer} #{dependency}.rb"
end
end
end
def inherited(child)
inherited_without_model(child)
return if child.controller_name == "application" # otherwise the ApplicationController in Rails will include itself
begin
child.model(Inflector.singularize(child.controller_name))
rescue LoadError
# No neither singular or plural model available for this controller
end
end
end
end
end
|
