Add a developer mode 'view source' button to crashed event tiles (#7537)

* Add a developer mode 'view source' button to crashed event tiles

* appease the linter

src/components/views/messages/TileErrorBoundary.tsx

@@ -1,5 +1,5 @@
 /*
-Copyright 2020 - 2021 The Matrix.org Foundation C.I.C.
+Copyright 2020 - 2022 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -24,6 +24,8 @@ import SdkConfig from "../../../SdkConfig";
 import { replaceableComponent } from "../../../utils/replaceableComponent";
 import BugReportDialog from '../dialogs/BugReportDialog';
 import AccessibleButton from '../elements/AccessibleButton';
+import SettingsStore from "../../../settings/SettingsStore";
+import ViewSource from "../../structures/ViewSource";
 
 interface IProps {
     mxEvent: MatrixEvent;
@@ -56,6 +58,12 @@ export default class TileErrorBoundary extends React.Component<IProps, IState> {
         });
     };
 
+    private onViewSource = (): void => {
+        Modal.createTrackedDialog('View Event Source', 'from crash', ViewSource, {
+            mxEvent: this.props.mxEvent,
+        }, 'mx_Dialog_viewsource');
+    };
+
     render() {
         if (this.state.error) {
             const { mxEvent } = this.props;
@@ -73,12 +81,20 @@ export default class TileErrorBoundary extends React.Component<IProps, IState> {
                 </AccessibleButton>;
             }
 
+            let viewSourceButton;
+            if (mxEvent && SettingsStore.getValue("developerMode")) {
+                viewSourceButton = <AccessibleButton onClick={this.onViewSource} kind="link_inline">
+                    { _t("View Source") }
+                </AccessibleButton>;
+            }
+
             return (<div className={classNames(classes)}>
                 <div className="mx_EventTile_line">
                     <span>
                         { _t("Can't load this message") }
                         { mxEvent && ` (${mxEvent.getType()})` }
                         { submitLogsButton }
+                        { viewSourceButton }
                     </span>
                 </div>
             </div>);