Refactor screen template rendering to the frontend namespace.

* Move the template rendering code for the frontend, update the caching slightly.
* Pass the template path as part of the screen setup information instead of constructing it on the fly.

app/controllers/frontend/screens_controller.rb

@@ -16,6 +16,8 @@ def setup
     rescue ActiveRecord::ActiveRecordError
       render :json => {}, :status => 404
     else
+      # Inject the path into an fake attribute so it gets sent with the setup info.
+      @screen.template.path = frontend_screen_template_path(@screen, @screen.template)
       respond_to do |format|
         format.json {
           render :json => @screen.to_json(
@@ -28,6 +30,7 @@ def setup
                   },
                 },
                 :only => [:id],
+                :methods => [:path]
               }
             }
           )

app/controllers/frontend/templates_controller.rb

@@ -0,0 +1,34 @@
+class Frontend::TemplatesController < ApplicationController
+
+  # GET /frontend/1/template/1
+  # Render the template for display on a screen.
+  def show
+    template = Template.find(params[:id])
+    if stale?(:last_modified => template.last_modified.utc, :etag => template, :public => true)
+      require'image_utility'
+      media = template.media.original.first
+      image = Magick::Image.from_blob(media.file_contents).first
+
+      # Resize the image to a height and width if they are both being set.
+      # Round these numbers up to ensure the image will at least fill
+      # the requested space.
+      height = params[:height].nil? ? nil : params[:height].to_f.ceil
+      width = params[:width].nil? ? nil : params[:width].to_f.ceil 
+
+      image = ImageUtility.resize(image, width, height, false)
+      case request.format
+        when Mime::Type.lookup_by_extension(:jpg)
+          image.format = "JPG"
+        when Mime::PNG
+          image.format = "PNG"
+        else
+          render :status => 406, :text => "Unacceptable image type." and return
+      end
+
+      send_data image.to_blob,
+                :filename => "#{template.name.underscore}.#{image.format.downcase}",
+                :type => image.mime_type, :disposition => 'inline'
+    end
+  end
+
+end

app/controllers/templates_controller.rb

@@ -93,39 +93,6 @@ def destroy
       format.xml  { head :ok }
     end
   end
-
-  # GET /template/1/display
-  # Render the template for display on a screen.
-  def display
-    require'image_utility'
-    @template = Template.find(params[:id])
-    @media = @template.media.original.first
-    image = Magick::Image.from_blob(@media.file_contents).first
-
-    # Resize the image to a height and width if they are both being set.
-    # Round these numbers up to ensure the image will at least fill
-    # the requested space.
-    width = nil
-    height = nil
-    height = params[:height].to_f.ceil unless params[:height].nil?
-    width = params[:width].to_f.ceil unless params[:width].nil?
-
-    image = ImageUtility.resize(image, width, height, false)
-    case request.format
-      when Mime::Type.lookup_by_extension(:jpg)
-        image.format = "JPG"
-      when Mime::PNG
-        image.format = "PNG"
-    end
-
-    # Set some reasonable cache headers
-    response.headers["Last-Modified"] = CGI.rfc1123_date(@template.last_modified)
-    expires_in 36.hours, :public => true
-
-    send_data image.to_blob,
-              :filename => "#{@template.name.underscore}.#{image.format.downcase}",
-              :type => image.mime_type, :disposition => 'inline'
-  end
 
   # GET /template/1/preview
   # Generate a preview of the template based on the request format.

app/helpers/frontend/templates_helper.rb

@@ -0,0 +1,2 @@
+module Frontend::TemplatesHelper
+end

app/models/template.rb

@@ -7,6 +7,9 @@ class Template < ActiveRecord::Base
 
   #Validations
   validates :name, :presence => true
+
+  #Placeholder attributes
+  attr_accessor :path
 
   # Given a string from an XML descriptor, build the template
   # to try and match the description.  Each position will be

config/routes.rb

@@ -17,6 +17,7 @@
           get :contents, :path => 'content'
         end
       end
+      resources :templates, :only => [:show]
     end
   end
   # End really dangerous routes.
@@ -31,7 +32,6 @@
     resources :positions
     member do
       get :preview
-      get :display
     end
     collection do
       post :import

public/frontend_js/template.js

@@ -28,9 +28,16 @@ concerto.frontend.Template = function(screen, opt_div) {
   /**
    * The template ID number.
    * @type {?number}
+   * @private
    */
   this.id = null;
 
+  /**
+   * The URL to the template.
+   * @type {?string}
+   */
+  this.path = null;
+
   /**
    * Positions being shown on this template.
    * @type {?Array.<concerto.frontend.Position>}
@@ -81,6 +88,7 @@ concerto.frontend.Template.prototype.createDiv_ = function() {
  */
 concerto.frontend.Template.prototype.load = function(data) {
   this.id = data.id;
+  this.path_ = data.path;
   goog.dom.setProperties(this.div_, {'id': 'template_' + this.id});
 
   this.render_();
@@ -104,7 +112,7 @@ concerto.frontend.Template.prototype.load = function(data) {
 concerto.frontend.Template.prototype.render_ = function() {
   var size = goog.style.getSize(this.div_);
 
-  var background_url = new goog.Uri('/templates/' + this.id + '/display');
+  var background_url = new goog.Uri(this.path_);
   background_url.setParameterValue('height', size.height);
   background_url.setParameterValue('width', size.width);
 

test/functional/frontend/screens_controller_test.rb

@@ -22,6 +22,7 @@ class Frontend::ScreensControllerTest < ActionController::TestCase
     assert_equal data['name'], screens(:one).name
     assert_equal data['template']['positions'].length,
                  screens(:one).template.positions.length
+    assert data['template']['path'].length > 0
   end
 
   test "cannot setup missing screen" do

test/functional/frontend/templates_controller_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class Frontend::TemplatesControllerTest < ActionController::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end

test/unit/helpers/frontend/templates_helper_test.rb

@@ -0,0 +1,4 @@
+require 'test_helper'
+
+class Frontend::TemplatesHelperTest < ActionView::TestCase
+end