     _.extend this, doc
 
 class VideoBlock extends ContextBlock
+  constructor: (doc) ->
+    super doc
+    @type = 'video'
+    @service ?= 'youtube'
   url: ->
     if @service is 'youtube'
       '//www.youtube.com/embed/' + @videoId

        new VideoBlock doc
      when 'text'
        new TextBlock doc
      else
        new ContextBlock doc


      '//img.youtube.com/vi/' + @videoId + '/0.jpg'

class MapBlock extends ContextBlock
  constructor: (doc) ->
    super doc
    @type = 'map'
    @service ?= 'google_maps'
  escape: (value) ->
    encodeURIComponent(value).replace(/%20/g, "+")
  url: ->
