Extract rendering from template into renderers

lib/rabl-fast-json.rb

@@ -8,20 +8,25 @@ require 'rabl-fast-json/version'
 require 'rabl-fast-json/helpers'
 require 'rabl-fast-json/template'
 require 'rabl-fast-json/compiler'
+
+require 'rabl-fast-json/renderer'
+
 require 'rabl-fast-json/library'
 require 'rabl-fast-json/handler'
 require 'rabl-fast-json/railtie'
 
+
+
 module RablFastJson
   extend self
-  
+
   mattr_accessor :cache_templates
   @@cache_templates = true
 
   def configure
     yield self
   end
-  
+
   def cache_templates?
     ActionController::Base.perform_caching && @@cache_templates
   end

lib/rabl-fast-json/handler.rb

@@ -4,7 +4,7 @@ module RablFastJson
       cattr_accessor :default_format
       self.default_format = 'application/json'
 
-      def self.call(template)        
+      def self.call(template)
         %{
           RablFastJson::Library.instance.
             get_rendered_template(#{template.source.inspect}, self)

lib/rabl-fast-json/library.rb

@@ -12,12 +12,12 @@ module RablFastJson
 
     def get_rendered_template(source, context)
       path = context.instance_variable_get(:@virtual_path)
-      @view_renderer = context.instance_variable_get(:@view_renderer)
+      @lookup_context = context.lookup_context
 
       compiled_template = get_compiled_template(path, source)
-      compiled_template.context = context
+
-      body = compiled_template.render
+      format = context.params[:format] || 'json'
-      ActiveSupport::JSON.encode(compiled_template.root_name ? { compiled_template.root_name => body } : body)
+      Renderers.const_get(format.upcase!).new(context).render(compiled_template)
     end
 
     def get_compiled_template(path, source)
@@ -32,7 +32,7 @@ module RablFastJson
     def get(path)
       template = @cached_templates[path]
       return template unless template.nil?
-      t = @view_renderer.lookup_context.find_template(path, [], false)
+      t = @lookup_context.find_template(path, [], false)
       get_compiled_template(path, t.source)
     end
   end

lib/rabl-fast-json/renderer.rb

@@ -0,0 +1,2 @@
+require 'rabl-fast-json/renderers/base'
+require 'rabl-fast-json/renderers/json'

lib/rabl-fast-json/renderers/base.rb

@@ -0,0 +1,108 @@
+module RablFastJson
+  module Renderers
+    class Base
+
+      def initialize(context) # :nodoc:
+        @_context = context
+        setup_render_context
+      end
+
+      #
+      # Render a template.
+      # Uses the compiled template source to get a hash with the actual
+      # data and then format the result according to the `format_result`
+      # method defined by the renderer.
+      #
+      def render(template)
+        collection_or_resource = @_context.instance_variable_get(template.data) if template.data
+        output_hash = collection_or_resource.respond_to?(:each) ? render_collection(collection_or_resource, template.source) :
+          render_resource(collection_or_resource, template.source)
+        output_hash = { template.root_name => output_hash } if template.root_name
+        format_output(output_hash)
+      end
+
+      #
+      # Format a hash into the desired output.
+      # Renderer subclasses must implement this method
+      #
+      def format_output(hash)
+        raise "Muse be implemented by renderer"
+      end
+
+      protected
+
+      #
+      # Render a single resource as a hash, according to the compiled
+      # template source passed.
+      #
+      def render_resource(data, source)
+        source.inject({}) { |output, current|
+          key, value = current
+
+          out = case value
+          when Symbol
+            data.send(value) # attributes
+          when Proc
+            instance_exec data, &value # node
+          when Array # node with condition
+            next output if !instance_exec data, &(value.first)
+            instance_exec data, &(value.last)
+          when Hash
+            current_value = value.dup
+            data_symbol = current_value.delete(:_data)
+            object = data_symbol.nil? ? data : data_symbol.to_s.start_with?('@') ? @_context.instance_variable_get(data_symbol) : data.send(data_symbol)
+
+            if key.to_s.start_with?('_') # glue
+              current_value.each_pair { |k, v|
+                output[k] = object.send(v)
+              }
+              next output
+            else # child
+              object.respond_to?(:each) ? render_collection(object, current_value) : render_resource(object, current_value)
+            end
+          end
+          output[key] = out
+          output
+        }
+      end
+
+      #
+      # Call the render_resource mtehod on each object of the collection
+      # and return an array of the returned values.
+      #
+      def render_collection(collection, source)
+        collection.map { |o| render_resource(o, source) }
+      end
+
+      def partial(template_path, options = {})
+        raise "No object was given to partial" unless options[:object]
+        object = options[:object]
+
+        return [] if object.respond_to?(:empty?) && object.empty?
+
+        template = Library.instance.get(template_path)
+        object.respond_to?(:each) ? render_collection(object, template.source) : render_resource(object, template.source)
+      end
+
+      #
+      # If a method is called inside a 'node' property or a 'if' lambda
+      # it will be passed to context if it exists or treated as a standard
+      # missing method.
+      #
+      def method_missing(name, *args, &block)
+        @context.respond_to?(name) ? @context.send(name, *args, &block) : super
+      end
+
+      #
+      # Copy assigns from controller's context into this
+      # renderer context to include instances variables when
+      # evaluating 'node' properties.
+      #
+      def setup_render_context
+        @_context.instance_variable_get(:@_assigns).each_pair { |k, v|
+          instance_variable_set("@#{k}", v) unless k.start_with?('_') || k == @data
+        }
+      end
+    end
+  end
+end

lib/rabl-fast-json/renderers/json.rb

@@ -0,0 +1,9 @@
+module RablFastJson
+  module Renderers
+    class JSON < Base
+      def format_output(hash)
+        ActiveSupport::JSON.encode(hash)
+      end
+    end
+  end
+end

lib/rabl-fast-json/template.rb

@@ -1,86 +1,11 @@
 module RablFastJson
   class CompiledTemplate
-    attr_accessor :source, :data, :root_name, :context
+    attr_accessor :source, :data, :root_name
 
     delegate :[], :[]=, :merge!, :to => :source
 
     def initialize
       @source = {}
     end
-    
-    def has_root_name?
-      !@root_name.nil?
-    end
-
-    def render
-      get_object_from_context
-      get_assigns_from_context
-      @object.respond_to?(:each) ? render_collection : render_resource
-    end
-  
-    def render_resource(data = nil, source = nil)
-      data ||= @object
-      source ||= @source
-      
-      source.inject({}) { |output, current|
-        key, value = current
-
-        out = case value
-        when Symbol
-          data.send(value) # attributes
-        when Proc
-          instance_exec data, &value # node
-        when Array # node with condition
-          next output if !instance_exec data, &(value.first) #value.first.call(data)
-          instance_exec data, &(value.last)
-        when Hash
-          current_value = value.dup
-          data_symbol = current_value.delete(:_data)
-          object = data_symbol.nil? ? data : data_symbol.to_s.start_with?('@') ? @context.instance_variable_get(data_symbol) : data.send(data_symbol)
-
-          if key.to_s.start_with?('_') # glue
-            current_value.each_pair { |k, v|
-              output[k] = object.send(v)
-            }
-            next output
-          else # child
-            object.respond_to?(:each) ? render_collection(object, current_value) : render_resource(object, current_value)
-          end
-        end
-        output[key] = out
-        output
-      }
-    end
-
-    def render_collection(collection = nil, source = nil)
-      collection ||= @object
-      collection.inject([]) { |output, o| output << render_resource(o, source) }
-    end
-    
-    def method_missing(name, *args, &block)
-      @context.respond_to?(name) ? @context.send(name, *args, &block) : super
-    end
-    
-    def partial(template_path, options = {})      
-      raise "No object was given to partial" if options[:object].nil?
-      object = options[:object]
-
-      return [] if object.respond_to?(:empty?) && object.empty?
-      
-      template = Library.instance.get(template_path)
-      object.respond_to?(:each) ? template.render_collection(object) : template.render_resource(object)
-    end
-    
-    protected
-    
-    def get_object_from_context
-      @object = @context.instance_variable_get(@data) if @data
-    end
-    
-    def get_assigns_from_context
-      @context.instance_variable_get(:@_assigns).each_pair { |k, v|
-        instance_variable_set("@#{k}", v) unless k.start_with?('_') || k == @data
-      }
-    end  
   end
 end

test/cache_templates_test.rb

@@ -4,31 +4,31 @@ class CacheTemplatesTest < ActiveSupport::TestCase
 
   setup do
     RablFastJson::Library.reset_instance
-    @library = RablFastJson::Library.instance 
+    @library = RablFastJson::Library.instance
-  end
-  
-  test "cache templates if perform_caching is active and cache_templates is enabled" do
     RablFastJson.cache_templates = true
-    ActionController::Base.stub(:perform_caching).and_return(true)    
+  end
+
+  test "cache templates if perform_caching is active and cache_templates is enabled" do
+    ActionController::Base.stub(:perform_caching).and_return(true)
     @library.get_compiled_template('some/path', "")
     t = @library.get_compiled_template('some/path', "attribute :id")
-    
+
     assert_equal({}, t.source)
   end
-  
+
   test "cached templates should not be modifiable in place" do
-    RablFastJson.cache_templates = true
     ActionController::Base.stub(:perform_caching).and_return(true)
     t = @library.get_compiled_template('some/path', "")
     assert_nil t.context
     t.context = "foobar"
     assert_nil @library.get_compiled_template('some/path', "").context
   end
-  
+
   test "don't cache templates cache_templates is enabled but perform_caching is not active" do
-    RablFastJson.cache_templates = true
+    ActionController::Base.stub(:perform_caching).and_return(false)
-    ActionController::Base.stub(:perform_caching).and_return(false)    
+    @library.get_compiled_template('some/path', "")
-    
+    t = @library.get_compiled_template('some/path', "attribute :id")
-    refute_equal @library.get_compiled_template('some/path', ""), @library.get_compiled_template('some/path', "")
+
+    assert_equal({ :id => :id }, t.source)
   end
 end

test/compiled_template_test.rb

@@ -13,6 +13,10 @@ class TestCompiledTemplate < ActiveSupport::TestCase
     @template.data = :@data
   end
 
+  def render_json_output
+    RablFastJson::Renderers::JSON.new(@context).render(@template)
+  end
+
   test "render object wth empty template" do
     @template.source = {}
     assert_equal({}, @template.render)