added delete_edge

frontend/assets/js/canvas.js

@@ -202,6 +202,20 @@ function draw_new_edge(edge) {
   return group;
 }
 
+function remove_canvas_edge(edge){
+  let konva_edge = stage.findOne('#' + edge["start"] + edge["end"]);
+  if (!konva_edge){
+    konva_edge = stage.findOne('#' + edge["end"] + edge["start"]);
+  }
+  if (konva_edge){
+    konva_edges.splice(konva_edges.indexOf(konva_edge),1);
+    graph_copy[edge["start"]].splice(graph_copy[edge["start"]].indexOf(edge["end"]),1);
+    graph_copy[edge["end"]].splice(graph_copy[edge["end"]].indexOf(edge["start"]),1);
+    konva_edge.remove();
+    edge_layer.draw();
+  }
+}
+
 function update_edge(konva_edge) {
   let line = konva_edge.children[0];
   let text = konva_edge.children[1];
@@ -404,6 +418,24 @@ function find_path(data) {
     .catch(error => console.error('Error:', error));
 }
 
+function delete_edge(data) {
+  if (data.length < 2) {
+    show_info("Select 2 nodes.");
+    return;
+  }
+  rest_req("DELETE", "edges/" + data[0].attrs.id + "/" + data[1].attrs.id, null)
+    .then(function(res) {
+      if (res["error"]) {
+        show_info(res["error"]);
+      } else {
+        remove_canvas_edge(res);
+        selected = [];
+        draw_selected_nodes();
+      }
+    })
+    .catch(error => console.error('Error:', error));
+}
+
 //-----------------------------------------------------------------------------
 
 function save_graph() {

frontend/index.html

@@ -25,6 +25,10 @@
           <img src="{{ url_for('static', filename='imgs/share.svg') }}">
           <h1>Find Path</h1>
         </button>
+        <button type="button" onclick="delete_edge(selected)">
+          <img src="{{ url_for('static', filename='imgs/drawing.svg') }}">
+          <h1>Delete Edge</h1>
+        </button>
       </nav>
       <footer>
         <div id="infobar"></div>

main.py

@@ -122,6 +122,15 @@ def create_edge():
     return jsonify(edge), 201
 
 
+@app.route('/api/edges/<start>/<end>', methods=['DELETE'])
+def delete_edge(start, end):
+    if start in graph and end in graph[start]:
+        del graph[start][end]
+        del graph[end][start]
+
+    return jsonify({"start":start,"end":end}), 200
+
+
 @app.route("/save")
 def save():
     try: