Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Tree: e7560bc787
318 lines (294 sloc) 10.808 kB
require 'abstract_controller/collector'
require 'active_support/core_ext/class/attribute'
require 'active_support/core_ext/object/inclusion'
module ActionController #:nodoc:
module MimeResponds
extend ActiveSupport::Concern
include ActionController::ImplicitRender
included do
class_attribute :responder, :mimes_for_respond_to
self.responder = ActionController::Responder
clear_respond_to
end
module ClassMethods
# Defines mime types that are rendered by default when invoking
# <tt>respond_with</tt>.
#
# Examples:
#
# respond_to :html, :xml, :json
#
# Specifies that all actions in the controller respond to requests
# for <tt>:html</tt>, <tt>:xml</tt> and <tt>:json</tt>.
#
# To specify on per-action basis, use <tt>:only</tt> and
# <tt>:except</tt> with an array of actions or a single action:
#
# respond_to :html
# respond_to :xml, :json, :except => [ :edit ]
#
# This specifies that all actions respond to <tt>:html</tt>
# and all actions except <tt>:edit</tt> respond to <tt>:xml</tt> and
# <tt>:json</tt>.
#
# respond_to :json, :only => :create
#
# This specifies that the <tt>:create</tt> action and no other responds
# to <tt>:json</tt>.
def respond_to(*mimes)
options = mimes.extract_options!
only_actions = Array(options.delete(:only)).map(&:to_s)
except_actions = Array(options.delete(:except)).map(&:to_s)
new = mimes_for_respond_to.dup
mimes.each do |mime|
mime = mime.to_sym
new[mime] = {}
new[mime][:only] = only_actions unless only_actions.empty?
new[mime][:except] = except_actions unless except_actions.empty?
end
self.mimes_for_respond_to = new.freeze
end
# Clear all mime types in <tt>respond_to</tt>.
#
def clear_respond_to
self.mimes_for_respond_to = ActiveSupport::OrderedHash.new.freeze
end
end
# 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.all
# end
#
# Here's the same action, with web-service support baked in:
#
# def index
# @people = Person.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,
# then it is an Ajax request and we render the JavaScript 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's 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 node), 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
# config/initializers/mime_types.rb as follows.
#
# Mime::Type.register "image/jpg", :jpg
#
# Respond to also allows you to specify a common block for different formats by using any:
#
# def index
# @people = Person.all
#
# respond_to do |format|
# format.html
# format.any(:xml, :json) { render request.format.to_sym => @people }
# end
# end
#
# In the example above, if the format is xml, it will render:
#
# render :xml => @people
#
# Or if the format is json:
#
# render :json => @people
#
# Since this is a common pattern, you can use the class method respond_to
# with the respond_with method to have the same results:
#
# class PeopleController < ApplicationController
# respond_to :html, :xml, :json
#
# def index
# @people = Person.all
# respond_with(@people)
# end
# end
#
# Be sure to check respond_with and respond_to documentation for more examples.
#
def respond_to(*mimes, &block)
raise ArgumentError, "respond_to takes either types or a block, never both" if mimes.any? && block_given?
if collector = retrieve_collector_from_mimes(mimes, &block)
response = collector.response
response ? response.call : default_render({})
end
end
# respond_with wraps a resource around a responder for default representation.
# First it invokes respond_to, if a response cannot be found (ie. no block
# for the request was given and template was not available), it instantiates
# an ActionController::Responder with the controller and resource.
#
# ==== Example
#
# def index
# @users = User.all
# respond_with(@users)
# end
#
# It also accepts a block to be given. It's used to overwrite a default
# response:
#
# def create
# @user = User.new(params[:user])
# flash[:notice] = "User was successfully created." if @user.save
#
# respond_with(@user) do |format|
# format.html { render }
# end
# end
#
# All options given to respond_with are sent to the underlying responder,
# except for the option :responder itself. Since the responder interface
# is quite simple (it just needs to respond to call), you can even give
# a proc to it.
#
# In order to use respond_with, first you need to declare the formats your
# controller responds to in the class level with a call to <tt>respond_to</tt>.
#
def respond_with(*resources, &block)
raise "In order to use respond_with, first you need to declare the formats your " <<
"controller responds to in the class level" if self.class.mimes_for_respond_to.empty?
if collector = retrieve_collector_from_mimes(&block)
options = resources.size == 1 ? {} : resources.extract_options!
options[:default_response] = collector.response
(options.delete(:responder) || self.class.responder).call(self, resources, options)
end
end
protected
# Collect mimes declared in the class method respond_to valid for the
# current action.
#
def collect_mimes_from_class_level #:nodoc:
action = action_name.to_s
self.class.mimes_for_respond_to.keys.select do |mime|
config = self.class.mimes_for_respond_to[mime]
if config[:except]
!action.in?(config[:except])
elsif config[:only]
action.in?(config[:only])
else
true
end
end
end
# Collects mimes and return the response for the negotiated format. Returns
# nil if :not_acceptable was sent to the client.
#
def retrieve_collector_from_mimes(mimes=nil, &block) #:nodoc:
mimes ||= collect_mimes_from_class_level
collector = Collector.new(mimes)
block.call(collector) if block_given?
format = collector.negotiate_format(request)
if format
self.content_type ||= format.to_s
lookup_context.formats = [format.to_sym]
lookup_context.rendered_format = lookup_context.formats.first
collector
else
head :not_acceptable
nil
end
end
class Collector #:nodoc:
include AbstractController::Collector
attr_accessor :order, :format
def initialize(mimes)
@order, @responses = [], {}
mimes.each { |mime| send(mime) }
end
def any(*args, &block)
if args.any?
args.each { |type| send(type, &block) }
else
custom(Mime::ALL, &block)
end
end
alias :all :any
def custom(mime_type, &block)
mime_type = Mime::Type.lookup(mime_type.to_s) unless mime_type.is_a?(Mime::Type)
@order << mime_type
@responses[mime_type] ||= block
end
def response
@responses[format] || @responses[Mime::ALL]
end
def negotiate_format(request)
@format = request.negotiate_mime(order)
end
end
end
end
Jump to Line
Something went wrong with that request. Please try again.