fix: GitHub Gist embed reliability, closes #1400

app/embeds/Gist.js

@@ -13,31 +13,16 @@ type Props = {|
 |};
 
 class Gist extends React.Component<Props> {
-  iframeNode: ?HTMLIFrameElement;
-
   static ENABLED = [URL_REGEX];
 
-  componentDidMount() {
-    this.updateIframeContent();
-  }
-
   get id() {
     const gistUrl = new URL(this.props.attrs.href);
     return gistUrl.pathname.split("/")[2];
   }
 
-  updateIframeContent() {
+  updateIframeContent = (iframe: ?HTMLIFrameElement) => {
-    const id = this.id;
-    const iframe = this.iframeNode;
     if (!iframe) return;
-
+    const id = this.id;
-    // We need to add some temporary content to the iframe for the document
-    // to be available, otherwise it's undefined on first load
-    const temp = document.getElementById("gist");
-    if (temp) {
-      temp.innerHTML = "";
-      temp.appendChild(iframe);
-    }
 
     // $FlowFixMe
     let doc = iframe.document;
@@ -56,16 +41,14 @@ class Gist extends React.Component<Props> {
     doc.open();
     doc.writeln(iframeHtml);
     doc.close();
-  }
+  };
 
   render() {
     const id = this.id;
 
     return (
       <iframe
-        ref={(ref) => {
+        ref={this.updateIframeContent}
-          this.iframeNode = ref;
-        }}
         type="text/html"
         frameBorder="0"
         width="100%"