Module: ActionWebService::Scaffolding::ClassMethods

Defined in:
lib/action_web_service/scaffolding.rb

Overview

Web service invocation scaffolding provides a way to quickly invoke web service methods in a controller. The generated scaffold actions have default views to let you enter the method parameters and view the results.

Example:

class ApiController < ActionController
  web_service_scaffold :invoke
end

This example generates an invoke action in the ApiController that you can navigate to from your browser, select the API method, enter its parameters, and perform the invocation.

If you want to customize the default views, create the following views in “app/views”:

  • action_name/methods.html.erb

  • action_name/parameters.html.erb

  • action_name/result.html.erb

  • action_name/layout.html.erb

Where action_name is the name of the action you gave to ClassMethods#web_service_scaffold.

You can use the default views in RAILS_DIR/lib/action_web_service/templates/scaffolds as a guide.

Instance Method Summary collapse

Instance Method Details

#web_service_scaffold(action_name) ⇒ Object

Generates web service invocation scaffolding for the current controller. The given action name can then be used as the entry point for invoking API methods from a web browser.



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# File 'lib/action_web_service/scaffolding.rb', line 40

def web_service_scaffold(action_name)
  add_template_helper(Helpers)
  module_eval <<-"end_eval", __FILE__, __LINE__ + 1
    def #{action_name}
      if request.method == :get
        setup_invocation_assigns
        render_invocation_scaffold 'methods'
      end
    end

    def #{action_name}_method_params
      if request.method == :get
        setup_invocation_assigns
        render_invocation_scaffold 'parameters'
      end
    end

    def #{action_name}_submit
      if request.method == :post
        setup_invocation_assigns
        protocol_name = params['protocol'] ? params['protocol'].to_sym : :soap
        case protocol_name
        when :soap
          @protocol = Protocol::Soap::SoapProtocol.create(self)
        when :xmlrpc
          @protocol = Protocol::XmlRpc::XmlRpcProtocol.create(self)
        end
        bm = Benchmark.measure do
          @protocol.register_api(@scaffold_service.api)
          post_params = params['method_params'] ? params['method_params'].dup : nil
          params = []
          @scaffold_method.expects.each_with_index do |spec, i|
            params << post_params[i.to_s]
          end if @scaffold_method.expects
          params = @scaffold_method.cast_expects(params)
          method_name = public_method_name(@scaffold_service.name, @scaffold_method.public_name)
          @method_request_xml = @protocol.encode_request(method_name, params, @scaffold_method.expects)
          new_request = @protocol.encode_action_pack_request(@scaffold_service.name, @scaffold_method.public_name, @method_request_xml)
          prepare_request(new_request, @scaffold_service.name, @scaffold_method.public_name)
          self.request = new_request
          if @scaffold_container.dispatching_mode != :direct
            request.parameters['action'] = @scaffold_service.name
          end
          dispatch_web_service_request
          @method_response_xml = response.body
          method_name, obj = @protocol.decode_response(@method_response_xml)
          return if handle_invocation_exception(obj)
          @method_return_value = @scaffold_method.cast_returns(obj)
        end
        @method_elapsed = bm.real
        reset_invocation_response
        render_invocation_scaffold 'result'
      end
    end

    private
      def setup_invocation_assigns
        @scaffold_class = self.class
        @scaffold_action_name = "#{action_name}"
        @scaffold_container = WebServiceModel::Container.new(self)
        if params['service'] && params['method']
          @scaffold_service = @scaffold_container.services.find{ |x| x.name == params['service'] }
          @scaffold_method = @scaffold_service.api_methods[params['method']]
        end
      end

      def render_invocation_scaffold(action)
        customized_template = "\#{self.class.controller_path}/#{action_name}/\#{action}"
        default_template = scaffold_path(action)
        begin
          content = @template.render(:file => customized_template)
        rescue ActionView::MissingTemplate
          content = @template.render(:file => default_template)
        end
        @template.instance_variable_set("@content_for_layout", content)
        if self.active_layout.nil?
          render :file => scaffold_path("layout")
        else
          render :file => self.active_layout, :use_full_path => true
        end
      end

      def scaffold_path(template_name)
        File.dirname(__FILE__) + "/templates/scaffolds/" + template_name + ".html.erb"
      end

      def reset_invocation_response
        erase_render_results
        response.instance_variable_set :@header, Rack::Utils::HeaderHash.new(::ActionController::Response::DEFAULT_HEADERS.merge("cookie" => []))
      end

      def public_method_name(service_name, method_name)
        if web_service_dispatching_mode == :layered && @protocol.is_a?(ActionWebService::Protocol::XmlRpc::XmlRpcProtocol)
          service_name + '.' + method_name
        else
          method_name
        end
      end

      def prepare_request(new_request, service_name, method_name)
        new_request.parameters.update(request.parameters)
        request.env.each{ |k, v| new_request.env[k] = v unless new_request.env.has_key?(k) }
        if web_service_dispatching_mode == :layered && @protocol.is_a?(ActionWebService::Protocol::Soap::SoapProtocol)
          new_request.env['HTTP_SOAPACTION'] = "/\#{controller_name()}/\#{service_name}/\#{method_name}"
        end
      end

      def handle_invocation_exception(obj)
        exception = nil
        if obj.respond_to?(:detail) && obj.detail.respond_to?(:cause) && obj.detail.cause.is_a?(Exception)
          exception = obj.detail.cause
        elsif obj.is_a?(XMLRPC::FaultException)
          exception = obj
        end
        return unless exception
        reset_invocation_response
        rescue_action(exception)
        true
      end
  end_eval
end