From 5a75a326aa4e0c0dbe476af5e1dad425a531ab5e Mon Sep 17 00:00:00 2001
From: Tony Chen <tonyc856@users.noreply.github.com>
Date: Wed, 5 Jun 2019 18:12:01 -0700
Subject: [PATCH] Prevent crashes on directly navigating to classifcations and
 results pages.

---
 src/SetList/SetList.js    | 20 ++++++++++++--------
 src/SetList/SetResults.js | 26 +++++++++++++++-----------
 2 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/src/SetList/SetList.js b/src/SetList/SetList.js
index 2027bab..32956b3 100644
--- a/src/SetList/SetList.js
+++ b/src/SetList/SetList.js
@@ -22,14 +22,18 @@ export default class SetList extends Component {
    }
 
    getClassificationResults = () => {
-      const data = this.props.location.state.results; // classification results passed in from Classify view
-      let categories = Object.keys(data);
-      const results = categories.map(category => {
-         return {category: category, data: data[category]};
-      });
-      this.setState({
-         results: results
-      });
+      if (this.props.location.state) {
+         const data = this.props.location.state.results; // classification results passed in from Classify view
+         let categories = Object.keys(data);
+         const results = categories.map(category => {
+            return {category: category, data: data[category]};
+         });
+         this.setState({
+            results: results
+         });
+      } else {
+         this.props.history.push('/');
+      }
    };
 
    renderResultsView = (index) => {
diff --git a/src/SetList/SetResults.js b/src/SetList/SetResults.js
index 7dc0085..deabc58 100644
--- a/src/SetList/SetResults.js
+++ b/src/SetList/SetResults.js
@@ -19,16 +19,20 @@ export default class SetResult extends Component {
    }
 
    componentWillMount() {
-      const jsonData = this.props.location.state.data;
-      const download = {
-         filename: this.generateDownloadFilename(jsonData),
-         rhef: this.generateDownloadHref(jsonData)
-      };
-      this.setState({
-         title: this.props.location.state.data.category, 
-         results: this.props.location.state.data.data,
-         download: download
-      });
+      if (this.props.location.state) {
+         const jsonData = this.props.location.state.data;
+         const download = {
+            filename: this.generateDownloadFilename(jsonData),
+            rhef: this.generateDownloadHref(jsonData)
+         };
+         this.setState({
+            title: this.props.location.state.data.category, 
+            results: this.props.location.state.data.data,
+            download: download
+         });
+      } else {
+         this.props.history.push('/');
+      }
    }
 
    generateDownloadFilename = (jsonData) => {
@@ -104,7 +108,7 @@ export default class SetResult extends Component {
                   </Button>
                </Grid>
                <Grid item>
-                  {this.renderClassifications(this.state.results)}
+                  {this.state.results ? this.renderClassifications(this.state.results) : null}
                </Grid>
             </Grid>   
             </div>