Added phantomjs script to save an image - this doesn't totally work yet, it has a error with famous

Added worker process to call the phantomjs script in app/workers
Added hook in models/map.rb to call the worker
Added calls to map.touch in mappings_controller.rb so it would get triggered correctly - I'm not sure how this will proceed moving forward

app/controllers/mappings_controller.rb

@@ -15,6 +15,8 @@ class MappingsController < ApplicationController
   def create
     @mapping = Mapping.new(params[:mapping])
 
+    @mapping.map.touch(:updated_at)
+
     if @mapping.save
       render json: @mapping, status: :created
     else
@@ -26,6 +28,8 @@ class MappingsController < ApplicationController
   def update
     @mapping = Mapping.find(params[:id])
 
+    @mapping.map.touch(:updated_at)
+
     if @mapping.update_attributes(params[:mapping])
       head :no_content
     else
@@ -36,8 +40,12 @@ class MappingsController < ApplicationController
   # DELETE /mappings/1.json
   def destroy
     @mapping = Mapping.find(params[:id])
+    @map = @mapping.map
+
     @mapping.destroy
 
+    @map.touch(:updated_at)
+
     head :no_content 
   end
-end
+end

app/models/map.rb

@@ -8,6 +8,8 @@ class Map < ActiveRecord::Base
   has_many :topics, :through => :topicmappings
   has_many :synapses, :through => :synapsemappings
 
+  after_touch :save_screenshot
+
   # This method associates the attribute ":image" with a file attachment
   has_attached_file :screenshot, :styles => {
    :thumb => ['188x126#', :png],
@@ -76,7 +78,7 @@ class Map < ActiveRecord::Base
     json[:updated_at] = self.updated_at_str
     json
   end
-  
+
   ##### PERMISSIONS ######
   
   # returns false if user not allowed to 'show' Topic, Synapse, or Map
@@ -105,4 +107,15 @@ class Map < ActiveRecord::Base
   	return true
   end
 
+  def save_screenshot
+    # TODO - this will grab a map every single frickin' time a map is touched
+    # we need a system to throttle the amount to 1/hour or something like that
+    # maybe have a flag - last time this map was screenshotted
+    # don't update if it was less than an hour ago
+    # except this has the issue of a user updating map 7x, and it only screenshotting after
+    # the first time. We only want it to screenhsot the 7th time.
+    # We need to store a timestamp somewhere and do processing every hour, I think.
+    GrabMapScreenshotWorker.perform_async(self.id)
+  end
+
 end

app/workers/grab_map_screenshot_worker.rb

@@ -0,0 +1,10 @@
+# app/workers/grab_map_screenshot_worker.rb
+class GrabMapScreenshotWorker
+  include Sidekiq::Worker
+
+  def perform(map_id)
+    Phantomjs.run('./script/phantomjs-save-screenshot.js', map_id.to_s) { |line|
+      puts line
+    }
+  end
+end

script/phantomjs-save-screenshot.js

@@ -0,0 +1,54 @@
+//parse arguments passed from command line (or more likely, from rails)
+var system = require('system');
+var args = system.args;
+if (args.length <= 1) {
+  phantom.exit();
+  throw new Error("no arguments supplied on command line");
+}//if
+
+//configurable variables - CHANGE ME
+var mapID = args[1];
+var url = 'http://localhost:3000/maps/' + mapID;
+var width = 400;
+var height = 400;
+var thumbsDirRelative = 'app/assets/images/map_thumbnails';
+
+//set up writing to filesystem
+var fs = require('fs');
+var thumbsDirectory = fs.workingDirectory + '/' + thumbsDirRelative; 
+if (!fs.isDirectory(thumbsDirectory)) {
+  fs.makeDirectory(thumbsDirectory);
+}//if
+
+//set up page and the area we'll render as a PNG
+var page = require('webpage').create();
+page.viewportSize = {
+  width: width,
+  height: height
+};
+page.clipRect = {
+  top: 32,
+  left: 32,
+  width: width - 32,
+  height: height - 32
+};
+page.open(url, function (status) {
+  if (status === 'success') {
+    //since this isn't evaluateAsync, it should also ensure the asynchronous
+    //js stuff is loaded too, hopefully?
+    page.evaluate(function() {
+      $(document).ready(function(){
+        $('.upperLeftUI, .upperRightUI, .mapControls, .infoAndHelp, #barometer_tab, .footer').hide();
+      });//document.ready
+    });//page.evaluate
+
+    //render page into map_thumbnails directory
+    var filename = thumbsDirectory + '/map' + mapID + '.png';
+    page.render(filename, 'PNG');
+
+  } else {
+    //failed to load
+  }//if
+
+  phantom.exit();
+});