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Diffstat (limited to 'actionpack/lib/action_controller/mime/responds.rb')
| -rw-r--r-- | actionpack/lib/action_controller/mime/responds.rb | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/mime/responds.rb b/actionpack/lib/action_controller/mime/responds.rb new file mode 100644 index 0000000000..bac225ab2a --- /dev/null +++ b/actionpack/lib/action_controller/mime/responds.rb @@ -0,0 +1,190 @@ +module ActionController #:nodoc: + module MimeResponds #:nodoc: + def self.included(base) + base.module_eval do + include ActionController::MimeResponds::InstanceMethods + end + 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 + # (format.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'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 + # 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(self) + block.call(responder) + responder.respond + end + end + + class Responder #:nodoc: + + def initialize(controller) + @controller = controller + @request = controller.request + @response = controller.response + + @mime_type_priority = @request.formats + + @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 + + @responses[mime_type] ||= Proc.new do + @response.template.formats = [mime_type.to_sym] + @response.content_type = mime_type.to_s + block_given? ? block.call : @controller.send(:render, :action => @controller.action_name) + end + end + + def any(*args, &block) + if args.any? + args.each { |type| send(type, &block) } + else + custom(@mime_type_priority.first, &block) + end + end + + def self.generate_method_for_mime(mime) + sym = mime.is_a?(Symbol) ? mime : mime.to_sym + const = sym.to_s.upcase + class_eval <<-RUBY, __FILE__, __LINE__ + 1 + def #{sym}(&block) # def html(&block) + custom(Mime::#{const}, &block) # custom(Mime::HTML, &block) + end # end + RUBY + end + + Mime::SET.each do |mime| + generate_method_for_mime(mime) + end + + def method_missing(symbol, &block) + mime_constant = Mime.const_get(symbol.to_s.upcase) + + if Mime::SET.include?(mime_constant) + self.class.generate_method_for_mime(mime_constant) + send(symbol, &block) + else + super + end + end + + def respond + for priority in @mime_type_priority + if priority == Mime::ALL + @responses[@order.first].call + return + else + if @responses[priority] + @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 + @controller.send :head, :not_acceptable + end + end + end + end +end |