optimized wiki page refresh code

frontend/src/wiki.js

@@ -77,13 +77,39 @@ class Wiki extends Component {
   }
 
   loadSidePanel = (initialPath) => {
-    if (initialPath === this.homePath || isDir === 'None') {
+
+    if (initialPath === this.homePath) {
+      if (hasIndex) {
+        this.loadIndexNode();
+      } else {
+        initialPath = '/';
+        this.loadNodeAndParentsByPath(initialPath);
+      }
+    }
+
+    if (initialPath !== this.homePath) {
+      if (isDir === 'None') {
+        if (hasIndex) {
+          this.loadIndexNode();
+        } else {
+          initialPath = '/';
+          this.loadNodeAndParentsByPath(initialPath);
+        }
+      } else {
+        if (hasIndex) {
+          this.loadIndexNode();
+        } else {
+          this.loadNodeAndParentsByPath(initialPath);
+        }
+      }
+    }
+  }
+
+  loadIndexNode = () => {
     seafileAPI.listWikiDir(slug, '/').then(res => {
       let tree = this.state.treeData;
       this.addFirstResponseListToNode(res.data.dirent_list, tree.root);
       let indexNode = tree.getNodeByPath(this.indexPath);
-        let homeNode = tree.getNodeByPath(this.homePath);
-        if (homeNode && indexNode) {
       seafileAPI.getWikiFileContent(slug, indexNode.path).then(res => {
         this.setState({
           treeData: tree,
@@ -92,18 +118,9 @@ class Wiki extends Component {
           isTreeDataLoading: false,
         });
       });
-        } else {
-          this.setState({
-            treeData: tree,
-            isTreeDataLoading: false,
-          });
-        }
     }).catch(() => {
       this.setState({isLoadFailed: true});
     });
-    } else {
-      this.loadNodeAndParentsByPath(initialPath);
-    }
   }
 
   showDir = (dirPath) => {