fix fetch content multiple times for same file

scm-ui/ui-webapp/src/repos/sources/components/content/SourcecodeViewer.tsx

@@ -12,6 +12,7 @@ type State = {
   content: string;
   error?: Error;
   loaded: boolean;
+  currentFileRevision: string;
 };
 
 class SourcecodeViewer extends React.Component<Props, State> {
@@ -20,31 +21,45 @@ class SourcecodeViewer extends React.Component<Props, State> {
 
     this.state = {
       content: "",
-      loaded: false
+      loaded: false,
+      currentFileRevision: ""
     };
   }
 
   componentDidMount() {
     const { file } = this.props;
-    getContent(file._links.self.href)
-      .then(result => {
-        if (result.error) {
-          this.setState({
-            ...this.state,
-            error: result.error,
-            loaded: true
-          });
-        } else {
-          this.setState({
-            ...this.state,
-            content: result,
-            loaded: true
-          });
-        }
-      })
-      .catch(err => {});
+    const { currentFileRevision } = this.state;
+    if (file.revision !== currentFileRevision) {
+      this.fetchContent();
+    }
   }
 
+  componentDidUpdate() {
+    const { file } = this.props;
+    const { currentFileRevision } = this.state;
+    if (file.revision !== currentFileRevision) {
+      this.fetchContent();
+    }
+  }
+
+  fetchContent = () => {
+    const { file } = this.props;
+    getContent(file._links.self.href)
+      .then(content => {
+        this.setState({
+          content,
+          loaded: true,
+          currentFileRevision: file.revision
+        });
+      })
+      .catch(error => {
+        this.setState({
+          error,
+          loaded: true
+        });
+      });
+  };
+
   render() {
     const { content, error, loaded } = this.state;
     const language = this.props.language;
@@ -70,17 +85,7 @@ export function getLanguage(language: string) {
 }
 
 export function getContent(url: string) {
-  return apiClient
-    .get(url)
-    .then(response => response.text())
-    .then(response => {
-      return response;
-    })
-    .catch(err => {
-      return {
-        error: err
-      };
-    });
+  return apiClient.get(url).then(response => response.text());
 }
 
 export default withTranslation("repos")(SourcecodeViewer);