can now remove synapses from maps with R key, although you can't really tell if you reload the page

app/assets/javascripts/Jit/graphsettings.js

@@ -871,7 +871,19 @@ function hideEdge(edge) {
 }
 
 function removeSelectedEdges() {
-  alert ("remove");
+  for (var i = 0; i < selectedEdges.length; i += 1) {
+    if (mapid != null) {
+      var edge = selectedEdges[i];
+      var id = edge.getData("id");
+      //delete mapping of id mapid
+      $.ajax({
+        type: "POST",
+        url: "/mappings/" + mapid + "/" + id + "/removefrommap",
+      });
+    }
+    hideEdge(edge);
+  }
+  selectedEdges = new Array();
 }
 
 function deleteSelectedEdges() {

app/controllers/synapses_controller.rb

@@ -116,6 +116,15 @@ class SynapsesController < ApplicationController
     end
   end
 
+  # POST mappings/:map_id/:synapse_id/removefrommap
+  def removefrommap
+    @mapping = Mapping.find_by_synapse_id_and_map_id(params[:synapse_id],params[:map_id])
+    @mapping.delete
+
+    respond_to do |format|
+      format.js
+    end
+  end
   
   # DELETE synapses/:id
   def destroy