From f4044a4cd74d63930185cb7bc05cb71fab41ea03 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tao=20Bror=20Bojl=C3=A9n?= <tao@btao.org>
Date: Wed, 20 Feb 2019 21:27:47 +0000
Subject: [PATCH] make frontend more resilient to a broken graph

---
 frontend/src/components/Graph.jsx | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/frontend/src/components/Graph.jsx b/frontend/src/components/Graph.jsx
index ba26e71..ad6659e 100644
--- a/frontend/src/components/Graph.jsx
+++ b/frontend/src/components/Graph.jsx
@@ -64,9 +64,12 @@ class GraphImpl extends React.Component {
     }
 
     componentDidUpdate() {
-        const sigma = this.sigmaComponent.current.sigma;
-        sigma.graph.nodes().map(this.colorNodes);
-        sigma.refresh();
+        const sigma = this.sigmaComponent && this.sigmaComponent.current.sigma;
+        // Check if sigma exists s.t. nothing breaks if the graph didn't load (for whatever reason)
+        if (sigma) {
+            sigma.graph.nodes().map(this.colorNodes);
+            sigma.refresh();
+        }
     }
 
     onClickNode = (e) => {