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
|
module ActionController #:nodoc:
module MimeResponds #:nodoc:
def self.included(base)
base.send(:include, ActionController::MimeResponds::InstanceMethods)
end
module InstanceMethods
# Without web-service support, an action which collects the data for displaying a list of people
# might look something like this:
#
# def index
# @people = Person.find(:all)
# end
#
# Here's the same action, with web-service support baked in:
#
# def index
# @people = Person.find(:all)
#
# respond_to do |format|
# format.html
# format.xml { render :xml => @people.to_xml }
# end
# end
#
# What that says is, "if the client wants HTML in response to this action, just respond as we
# would have before, but if the client wants XML, return them the list of people in XML format."
# (Rails determines the desired response format from the HTTP Accept header submitted by the client.)
#
# Supposing you have an action that adds a new person, optionally creating their company
# (by name) if it does not already exist, without web-services, it might look like this:
#
# def create
# @company = Company.find_or_create_by_name(params[:company][:name])
# @person = @company.people.create(params[:person])
#
# redirect_to(person_list_url)
# end
#
# Here's the same action, with web-service support baked in:
#
# def create
# company = params[:person].delete(:company)
# @company = Company.find_or_create_by_name(company[:name])
# @person = @company.people.create(params[:person])
#
# respond_to do |format|
# format.html { redirect_to(person_list_url) }
# format.js
# format.xml { render :xml => @person.to_xml(:include => @company) }
# end
# end
#
# If the client wants HTML, we just redirect them back to the person list. If they want Javascript
# (wants.js), then it is an RJS request and we render the RJS template associated with this action.
# Lastly, if the client wants XML, we render the created person as XML, but with a twist: we also
# include the person’s company in the rendered XML, so you get something like this:
#
# <person>
# <id>...</id>
# ...
# <company>
# <id>...</id>
# <name>...</name>
# ...
# </company>
# </person>
#
# Note, however, the extra bit at the top of that action:
#
# company = params[:person].delete(:company)
# @company = Company.find_or_create_by_name(company[:name])
#
# This is because the incoming XML document (if a web-service request is in process) can only contain a
# single root-node. So, we have to rearrange things so that the request looks like this (url-encoded):
#
# person[name]=...&person[company][name]=...&...
#
# And, like this (xml-encoded):
#
# <person>
# <name>...</name>
# <company>
# <name>...</name>
# </company>
# </person>
#
# In other words, we make the request so that it operates on a single entity—a person. Then, in the action,
# we extract the company data from the request, find or create the company, and then create the new person
# with the remaining data.
#
# Note that you can define your own XML parameter parser which would allow you to describe multiple entities
# in a single request (i.e., by wrapping them all in a single root note), but if you just go with the flow
# and accept Rails' defaults, life will be much easier.
#
# If you need to use a MIME type which isn't supported by default, you can register your own handlers in
# environment.rb as follows.
#
# Mime::Type.register "image/jpg", :jpg
def respond_to(*types, &block)
raise ArgumentError, "respond_to takes either types or a block, never both" unless types.any? ^ block
block ||= lambda { |responder| types.each { |type| responder.send(type) } }
responder = Responder.new(block.binding)
block.call(responder)
responder.respond
end
end
class Responder #:nodoc:
default_block_format = <<-END
Proc.new {
@template.template_format = '%s'
render :action => "\#{action_name}", :content_type => Mime::%s
}
END
DEFAULT_BLOCKS = [:html, :js, :xml].inject({}) do |memo, ext|
default_block = default_block_format % [ext, ext.to_s.upcase]
memo.update(ext => default_block)
end
def initialize(block_binding)
@block_binding = block_binding
@mime_type_priority = eval(
"(params[:format] && Mime::EXTENSION_LOOKUP[params[:format]]) ? " +
"[ Mime::EXTENSION_LOOKUP[params[:format]] ] : request.accepts",
block_binding
)
@order = []
@responses = {}
end
def custom(mime_type, &block)
mime_type = mime_type.is_a?(Mime::Type) ? mime_type : Mime::Type.lookup(mime_type.to_s)
@order << mime_type
if block_given?
@responses[mime_type] = Proc.new do
eval <<-END, @block_binding
@template.template_format = '#{mime_type.to_sym}'
response.content_type = '#{mime_type.to_s}'
END
block.call
end
else
if source = DEFAULT_BLOCKS[mime_type.to_sym]
@responses[mime_type] = eval(source, @block_binding)
else
raise ActionController::RenderError, "Expected a block but none was given for custom mime handler #{mime_type}"
end
end
end
def any(*args, &block)
args.each { |type| send(type, &block) }
end
def method_missing(symbol, &block)
mime_constant = symbol.to_s.upcase
if Mime::SET.include?(Mime.const_get(mime_constant))
custom(Mime.const_get(mime_constant), &block)
else
super
end
end
def respond
for priority in @mime_type_priority
if priority == Mime::ALL
@responses[@order.first].call
return
else
if priority === @order
@responses[priority].call
return # mime type match found, be happy and return
end
end
end
if @order.include?(Mime::ALL)
@responses[Mime::ALL].call
else
eval 'render(:nothing => true, :status => "406 Not Acceptable")', @block_binding
end
end
end
end
end
|
