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
|
module ActionController
# Polymorphic URL helpers are methods for smart resolution to a named route call when
# given an Active Record model instance. They are to be used in combination with
# ActionController::Resources.
#
# These methods are useful when you want to generate correct URL or path to a RESTful
# resource without having to know the exact type of the record in question.
#
# Nested resources and/or namespaces are also supported, as illustrated in the example:
#
# polymorphic_url([:admin, @article, @comment])
#
# results in:
#
# admin_article_comment_url(@article, @comment)
#
# == Usage within the framework
#
# Polymorphic URL helpers are used in a number of places throughout the Rails framework:
#
# * <tt>url_for</tt>, so you can use it with a record as the argument, e.g.
# <tt>url_for(@article)</tt>;
# * ActionView::Helpers::FormHelper uses <tt>polymorphic_path</tt>, so you can write
# <tt>form_for(@article)</tt> without having to specify <tt>:url</tt> parameter for the form
# action;
# * <tt>redirect_to</tt> (which, in fact, uses <tt>url_for</tt>) so you can write
# <tt>redirect_to(post)</tt> in your controllers;
# * ActionView::Helpers::AtomFeedHelper, so you don't have to explicitly specify URLs
# for feed entries.
#
# == Prefixed polymorphic helpers
#
# In addition to <tt>polymorphic_url</tt> and <tt>polymorphic_path</tt> methods, a
# number of prefixed helpers are available as a shorthand to <tt>:action => "..."</tt>
# in options. Those are:
#
# * <tt>edit_polymorphic_url</tt>, <tt>edit_polymorphic_path</tt>
# * <tt>new_polymorphic_url</tt>, <tt>new_polymorphic_path</tt>
# * <tt>formatted_polymorphic_url</tt>, <tt>formatted_polymorphic_path</tt>
#
# Example usage:
#
# edit_polymorphic_path(@post) # => "/posts/1/edit"
# formatted_polymorphic_path([@post, :pdf]) # => "/posts/1.pdf"
module PolymorphicRoutes
# Constructs a call to a named RESTful route for the given record and returns the
# resulting URL string. For example:
#
# # calls post_url(post)
# polymorphic_url(post) # => "http://example.com/posts/1"
# polymorphic_url([blog, post]) # => "http://example.com/blogs/1/posts/1"
# polymorphic_url([:admin, blog, post]) # => "http://example.com/admin/blogs/1/posts/1"
# polymorphic_url([user, :blog, post]) # => "http://example.com/users/1/blog/posts/1"
#
# ==== Options
#
# * <tt>:action</tt> - Specifies the action prefix for the named route:
# <tt>:new</tt>, <tt>:edit</tt>, or <tt>:formatted</tt>. Default is no prefix.
# * <tt>:routing_type</tt> - Allowed values are <tt>:path</tt> or <tt>:url</tt>.
# Default is <tt>:url</tt>.
#
# ==== Examples
#
# # an Article record
# polymorphic_url(record) # same as article_url(record)
#
# # a Comment record
# polymorphic_url(record) # same as comment_url(record)
#
# # it recognizes new records and maps to the collection
# record = Comment.new
# polymorphic_url(record) # same as comments_url()
#
def polymorphic_url(record_or_hash_or_array, options = {})
if record_or_hash_or_array.kind_of?(Array)
record_or_hash_or_array = record_or_hash_or_array.compact
record_or_hash_or_array = record_or_hash_or_array[0] if record_or_hash_or_array.size == 1
end
record = extract_record(record_or_hash_or_array)
format = extract_format(record_or_hash_or_array, options)
namespace = extract_namespace(record_or_hash_or_array)
args = case record_or_hash_or_array
when Hash; [ record_or_hash_or_array ]
when Array; record_or_hash_or_array.dup
else [ record_or_hash_or_array ]
end
inflection =
case
when options[:action].to_s == "new"
args.pop
:singular
when record.respond_to?(:new_record?) && record.new_record?
args.pop
:plural
else
:singular
end
args.delete_if {|arg| arg.is_a?(Symbol) || arg.is_a?(String)}
args << format if format
named_route = build_named_route_call(record_or_hash_or_array, namespace, inflection, options)
url_options = options.except(:action, :routing_type, :format)
unless url_options.empty?
args.last.kind_of?(Hash) ? args.last.merge!(url_options) : args << url_options
end
__send__(named_route, *args)
end
# Returns the path component of a URL for the given record. It uses
# <tt>polymorphic_url</tt> with <tt>:routing_type => :path</tt>.
def polymorphic_path(record_or_hash_or_array, options = {})
options[:routing_type] = :path
polymorphic_url(record_or_hash_or_array, options)
end
%w(edit new formatted).each do |action|
module_eval <<-EOT, __FILE__, __LINE__
def #{action}_polymorphic_url(record_or_hash, options = {})
polymorphic_url(record_or_hash, options.merge(:action => "#{action}"))
end
def #{action}_polymorphic_path(record_or_hash, options = {})
polymorphic_url(record_or_hash, options.merge(:action => "#{action}", :routing_type => :path))
end
EOT
end
private
def action_prefix(options)
options[:action] ? "#{options[:action]}_" : options[:format] ? "formatted_" : ""
end
def routing_type(options)
options[:routing_type] || :url
end
def build_named_route_call(records, namespace, inflection, options = {})
unless records.is_a?(Array)
record = extract_record(records)
route = ''
else
record = records.pop
route = records.inject("") do |string, parent|
if parent.is_a?(Symbol) || parent.is_a?(String)
string << "#{parent}_"
else
string << "#{RecordIdentifier.__send__("singular_class_name", parent)}_"
end
end
end
if record.is_a?(Symbol) || record.is_a?(String)
route << "#{record}_"
else
route << "#{RecordIdentifier.__send__("#{inflection}_class_name", record)}_"
end
action_prefix(options) + namespace + route + routing_type(options).to_s
end
def extract_record(record_or_hash_or_array)
case record_or_hash_or_array
when Array; record_or_hash_or_array.last
when Hash; record_or_hash_or_array[:id]
else record_or_hash_or_array
end
end
def extract_format(record_or_hash_or_array, options)
if options[:action].to_s == "formatted" && record_or_hash_or_array.is_a?(Array)
record_or_hash_or_array.pop
elsif options[:format]
options[:format]
else
nil
end
end
# Remove the first symbols from the array and return the url prefix
# implied by those symbols.
def extract_namespace(record_or_hash_or_array)
return "" unless record_or_hash_or_array.is_a?(Array)
namespace_keys = []
while (key = record_or_hash_or_array.first) && key.is_a?(String) || key.is_a?(Symbol)
namespace_keys << record_or_hash_or_array.shift
end
namespace_keys.map {|k| "#{k}_"}.join
end
end
end
|
