+# visualization.Paths class
+# displays crumbs by intervention as a path
+# 
+# @data is an array of hashes containing info to display
+# @layer is the layer name
+# 
+# ==== examples
+#
+# @data is an array of hashes built according to the following model: 
+# * minimal example of a hash representing a crumb: 
+#   item  {  
+#           name:         <intervention name>,  # may be the date, the doer's name, whatever you want as long as all the crumbs
+#                                               # for a given intervention have the same one. this is what is called in the 
+#                                               # VisualizationHelper to build the legend if you wrote something like:
+#                                               #   = visualization do |v|
+#                                               #     - v.serie :crumbs, my_array_of_crumbs_hashes
+#                                               #     - v.paths :name, :crumbs
+#                                               # :name being the @layer parameter the constructor requires. 
+#
+#           nature:       crumb.nature,         # proper to the crumb. May be one of the natures enumerated in Crumb model. 
+#                                               # this option is used to display particular points bigger and to change the 
+#                                               # path opacity for parts that correspond to actual works (points between a hard_start)
+#                                               # and a hard_stop crumb
+#
+#           shape:        crumb.geolocation,    # proper to the crumb. contains the actual crumb location as a Charta::Geometry object.
+#                                               # This is what is used to draw the crumb on the map
+#         }
+
 class visualization.Paths
 
   constructor: (@layer, @data, options = {}) ->

    @items.find (item, index, array) ->
      item.name == name

  # Check if categories are valid
  valid: () ->
    @items.length > 0


        group.push(crumbLayer)
    group

  # Build HTML legend for given paths computed layer
  buildLegend: () ->
    html  = "<div class='leaflet-legend-item' id='legend-#{@layer.name}'>"
    html += "<h3>#{@layer.label}</h3>"
