Refactor RablRails#render to use standard library

methods.

Emulate a render and lookup context like Rails.

lib/rabl-rails/renderer.rb

@@ -6,18 +6,53 @@ module RablRails
     mattr_reader :view_path
     @@view_path = 'app/views'
 
+    class LookupContext
+      T = Struct.new(:source)
+
+      def initialize(view_path, format)
+        @view_path = view_path || RablRails::Renderer.view_path
+        @format = format
+      end
+
+      #
+      # Manually find given rabl template file with given format.
+      # View path can be set via options, otherwise default Rails
+      # path is used
+      #
+      def find_template(name, opt, partial = false)
+        path = File.join(@view_path, "#{name}.#{@format}.rabl")
+        File.exists?(path) ? T.new(File.read(path)) : nil
+      end
+    end
+
     #
     # Context class to emulate normal rendering view
     # context
     #
     class Context
-      def initialize
+      attr_reader :format
+      attr_accessor :target_object
+
+      def initialize(path, options)
+        @virtual_path = path
+        @format = options.delete(:format) || 'json'
         @_assigns = {}
+        @options = options
+
+        options[:locals].each { |k, v| @_assigns[k.to_s] = v } if options[:locals]
       end
 
       def assigns
         @_assigns
       end
+
+      def params
+        { format: format }
+      end
+
+      def lookup_context
+        @lookup_context ||= LookupContext.new(@options[:view_path], format)
+      end
     end
   
     #
@@ -30,29 +65,14 @@ module RablRails
     # an option: { format: 'xml' }
     #
     def render(object, template, options = {})
-      format = options.delete(:format) || 'json'
       object = options[:locals].delete(:object) if !object && options[:locals]
 
-      source = find_template(template, format, options.delete(:view_path))
-      compiled_template = Compiler.new.compile_source(source)
+      c = Context.new(template, options)
+      c.target_object = object
 
-      c = Context.new
-      c.assigns[compiled_template.data.to_s[1..-1]] = object if compiled_template.data
+      t = c.lookup_context.find_template(template, [], false)
 
-      Renderers.const_get(format.upcase!).new(c).render(compiled_template)
-    end
-  
-    private
-  
-    #
-    # Manually find given rabl template file with given format.
-    # View path can be set via options, otherwise default Rails
-    # path is used
-    #
-    def find_template(name, format, view_path = nil)
-      view_path ||= self.view_path
-      path = File.join(view_path, "#{name}.#{format}.rabl")
-      File.exists?(path) ? File.read(path) : nil
+      Library.instance.get_rendered_template(t.source, c)
     end
   end
 end

lib/rabl-rails/renderers/base.rb

@@ -19,6 +19,7 @@ module RablRails
       #
       def render(template)
         collection_or_resource = instance_variable_get(template.data) if template.data
+        collection_or_resource = @_context.target_object unless collection_or_resource || template.data == false || !@_context.respond_to?(:target_object)
         output_hash = collection_or_resource.respond_to?(:each) ? render_collection(collection_or_resource, template.source) :
           render_resource(collection_or_resource, template.source)
         options[:root_name] = template.root_name

test/render_test.rb

@@ -0,0 +1,52 @@
+require 'test_helper'
+require 'pathname'
+require 'tmpdir'
+
+class RenderTest < ActiveSupport::TestCase
+
+  setup do
+    @user = User.new(1, 'Marty')
+    @user.stub(:respond_to?).with(:each).and_return(false)
+    @tmp_path = Pathname.new(Dir.mktmpdir)
+  end
+
+  test "allow object to be passed as an option" do
+    File.open(@tmp_path + "nil.json.rabl", "w") do |f|
+      f.puts %q{
+        object :@user
+        attributes :name
+      }
+    end
+
+    assert_equal %q({"user":{"name":"Marty"}}), RablRails.render(nil, 'nil', locals: { object: @user }, view_path: @tmp_path)
+  end
+
+  test "load source from file" do
+    File.open(@tmp_path + "show.json.rabl", "w") do |f|
+      f.puts %q{
+        object :@user
+        attributes :id, :name
+      }
+    end
+
+    assert_equal %q({"user":{"id":1,"name":"Marty"}}), RablRails.render(@user, 'show', view_path: @tmp_path)
+  end
+
+  test "handle path for extends" do
+    File.open(@tmp_path + "extend.json.rabl", "w") do |f|
+      f.puts %q{
+        object :@user
+        extends 'base'
+      }
+    end
+
+    File.open(@tmp_path + "base.json.rabl", "w") do |f|
+      f.puts %q{
+        attribute :name, as: :extended_name
+      }
+    end
+
+    assert_equal %q({"user":{"extended_name":"Marty"}}), RablRails.render(@user, 'extend', view_path: @tmp_path)
+  end
+
+end