Add selected node id to session storage.

Author: Robert Jackson

app/services/graph.js

@@ -6,28 +6,44 @@ const {
   getOwner
 } = Ember;
 
-const STORAGE_KEY = `${config.storageVersion}_graph-data`;
+const DATA_STORAGE_KEY = `${config.storageVersion}_graph-data`;
+const SELECTED_NODE_STORAGE_KEY = `${config.storageVersion}_selected-node-id`;
 
 export default Ember.Service.extend({
   init() {
     this._super(...arguments);
 
-    let data = sessionStorage.getItem(STORAGE_KEY);
+    let data = sessionStorage.getItem(DATA_STORAGE_KEY);
     if (data) {
       this.setGraph(JSON.parse(data));
     }
+
+    let selectedNodeId = sessionStorage.getItem(SELECTED_NODE_STORAGE_KEY);
+    if (selectedNodeId && data) {
+      let graph = this.get('graph');
+      for (let node of graph.dfsIterator()) {
+        if (node.id === selectedNodeId) {
+          this.set('selectedNode', node);
+          break;
+        }
+      }
+    }
   },
 
   setGraph(data) {
     let graph = heimdallGraph.loadFromJSON(data);
 
-    sessionStorage.setItem(STORAGE_KEY, JSON.stringify(data));
+    try {
+      sessionStorage.setItem(DATA_STORAGE_KEY, JSON.stringify(data));
+    } catch (e) {}
 
     this.set('data', data);
     this.set('graph', graph);
   },
 
   selectNode(node) {
+    sessionStorage.setItem(SELECTED_NODE_STORAGE_KEY, node.id);
+
     this.set('selectedNode', node);
     getOwner(this).lookup('router:main').transitionTo('selected-node');
   }