Fix embedded iframe links not updating with code state (#8166)

## Summary
Fixes the issue where the "Edit on Compiler Explorer" link in embedded
iframes doesn't update with the current code state, staying as "/"
instead of including the serialized state.

## Changes
- Refactored `Sharing` class into a base class `SharingBase` that
handles state tracking and embedded link updates
- `Sharing` class now extends `SharingBase` and adds the full sharing UI
features
- Created `initialiseSharing()` function that instantiates the
appropriate class based on embedded mode
- Updated `main.ts` to use the new initialization function
- Updated `history.ts` to use `SharingBase.filterComponentState()`
instead of `Sharing.filterComponentState()`

## Testing
- TypeScript compilation passes (`npm run ts-check`)
- Linting passes (`npm run lint`)
- Tests pass (`npm run test-min`)
- Manual browser testing confirms embedded links now update correctly

Closes #8097

🤖 Generated with [Claude Code](https://claude.ai/code)

---------

Co-authored-by: Claude <noreply@anthropic.com>

static/history.ts

@@ -24,7 +24,7 @@
 
 import _ from 'underscore';
 import {localStorage} from './local.js';
-import {Sharing} from './sharing.js';
+import {SharingBase} from './sharing.js';
 
 const maxHistoryEntries = 30;
 export type HistorySource = {dt: number; source: string};
@@ -100,7 +100,7 @@ export function trackHistory(layout: any) {
     let lastState: string | null = null;
     const debouncedPush = _.debounce(push, 500);
     layout.on('stateChanged', () => {
-        const stringifiedConfig = JSON.stringify(Sharing.filterComponentState(layout.toConfig()));
+        const stringifiedConfig = JSON.stringify(SharingBase.filterComponentState(layout.toConfig()));
         if (stringifiedConfig !== lastState) {
             lastState = stringifiedConfig;
             debouncedPush(stringifiedConfig);

static/main.ts

@@ -64,7 +64,7 @@ import {Presentation} from './presentation.js';
 import {Printerinator} from './print-view.js';
 import {setupRealDark, takeUsersOutOfRealDark} from './real-dark.js';
 import {Settings, SiteSettings} from './settings.js';
-import {Sharing} from './sharing.js';
+import {initialiseSharing} from './sharing.js';
 import {Themer} from './themes.js';
 import * as url from './url.js';
 import {formatISODate, updateAndCalcTopBarHeight} from './utils.js';
@@ -779,7 +779,7 @@ function start() {
 
     History.trackHistory(layout);
     setupSiteTemplateWidgetButton(layout);
-    if (!options.embedded) new Sharing(layout);
+    initialiseSharing(layout, !!options.embedded);
     new Printerinator(hub, themer);
 
     hub.layout.eventHub.emit('settingsChange', settings); // Ensure everyone knows the settings

static/sharing.ts

@@ -85,10 +85,61 @@ const shareServices = {
     },
 };
 
-export class Sharing {
-    private layout: GoldenLayout;
-    private lastState: any;
+// Base class that handles state tracking and embedded link updates
+export class SharingBase {
+    protected layout: GoldenLayout;
+    protected lastState: string | null = null;
 
+    constructor(layout: GoldenLayout) {
+        this.layout = layout;
+        this.initCallbacks();
+    }
+
+    protected initCallbacks(): void {
+        this.layout.on('stateChanged', this.onStateChanged.bind(this));
+    }
+
+    protected onStateChanged(): void {
+        const config = SharingBase.filterComponentState(this.layout.toConfig());
+        this.ensureUrlIsNotOutdated(config);
+
+        // Update embedded links if present (works in both modes)
+        if (options.embedded) {
+            const strippedToLast = window.location.pathname.substring(0, window.location.pathname.lastIndexOf('/') + 1);
+            $('a.link').prop('href', strippedToLast + '#' + url.serialiseState(config));
+        }
+    }
+
+    protected ensureUrlIsNotOutdated(config: any): void {
+        const stringifiedConfig = JSON.stringify(config);
+        if (stringifiedConfig !== this.lastState) {
+            if (this.lastState != null && window.location.pathname !== window.httpRoot) {
+                window.history.replaceState(null, '', window.httpRoot);
+            }
+            this.lastState = stringifiedConfig;
+        }
+    }
+
+    public static filterComponentState(config: any): any {
+        function filterComponentStateImpl(component: any) {
+            if (component.content) {
+                for (let i = 0; i < component.content.length; i++) {
+                    filterComponentStateImpl(component.content[i]);
+                }
+            }
+
+            if (component.componentState) {
+                delete component.componentState.selection;
+            }
+        }
+
+        config = cloneDeep(config);
+        filterComponentStateImpl(config);
+        return config;
+    }
+}
+
+export class Sharing extends SharingBase {
     private readonly share: JQuery;
     private readonly shareTooltipTarget: JQuery;
     private readonly shareShort: JQuery;
@@ -100,9 +151,8 @@ export class Sharing {
     private clippyButton: ClipboardJS | null;
     private readonly shareLinkDialog: HTMLElement;
 
-    constructor(layout: any) {
-        this.layout = layout;
-        this.lastState = null;
+    constructor(layout: GoldenLayout) {
+        super(layout);
         this.shareLinkDialog = unwrap(document.getElementById('sharelinkdialog'), 'Share modal element not found');
 
         this.share = $('#share');
@@ -119,17 +169,16 @@ export class Sharing {
         this.clippyButton = null;
 
         this.initButtons();
-        this.initCallbacks();
+        this.initFullCallbacks();
     }
 
-    private initCallbacks(): void {
+    private initFullCallbacks(): void {
         this.layout.eventHub.on('displaySharingPopover', () => {
             this.openShareModalForType(LinkType.Short);
         });
         this.layout.eventHub.on('copyShortLinkToClip', () => {
             this.copyLinkTypeToClipboard(LinkType.Short);
         });
-        this.layout.on('stateChanged', this.onStateChanged.bind(this));
 
         this.shareLinkDialog.addEventListener('show.bs.modal', this.onOpenModalPane.bind(this));
         this.shareLinkDialog.addEventListener('hidden.bs.modal', this.onCloseModalPane.bind(this));
@@ -152,25 +201,6 @@ export class Sharing {
         });
     }
 
-    private onStateChanged(): void {
-        const config = Sharing.filterComponentState(this.layout.toConfig());
-        this.ensureUrlIsNotOutdated(config);
-        if (options.embedded) {
-            const strippedToLast = window.location.pathname.substring(0, window.location.pathname.lastIndexOf('/') + 1);
-            $('a.link').prop('href', strippedToLast + '#' + url.serialiseState(config));
-        }
-    }
-
-    private ensureUrlIsNotOutdated(config: any): void {
-        const stringifiedConfig = JSON.stringify(config);
-        if (stringifiedConfig !== this.lastState) {
-            if (this.lastState != null && window.location.pathname !== window.httpRoot) {
-                window.history.replaceState(null, '', window.httpRoot);
-            }
-            this.lastState = stringifiedConfig;
-        }
-    }
-
     private static bindToLinkType(bind: string): LinkType {
         switch (bind) {
             case 'Full':
@@ -466,28 +496,6 @@ export class Sharing {
         return (navigator.clipboard as Clipboard | undefined) !== undefined;
     }
 
-    public static filterComponentState(config: any, keysToRemove: [string] = ['selection']): any {
-        function filterComponentStateImpl(component: any) {
-            if (component.content) {
-                for (let i = 0; i < component.content.length; i++) {
-                    filterComponentStateImpl(component.content[i]);
-                }
-            }
-
-            if (component.componentState) {
-                Object.keys(component.componentState)
-                    .filter(e => keysToRemove.includes(e))
-                    .forEach(key => {
-                        delete component.componentState[key];
-                    });
-            }
-        }
-
-        config = cloneDeep(config);
-        filterComponentStateImpl(config);
-        return config;
-    }
-
     private static updateShares(container: JQuery, url: string): void {
         const baseTemplate = $('#share-item');
         _.each(shareServices, (service, serviceName) => {
@@ -508,3 +516,14 @@ export class Sharing {
         });
     }
 }
+
+// Initialize sharing functionality based on whether we're in embedded mode or not
+export function initialiseSharing(layout: GoldenLayout, isEmbedded: boolean): void {
+    if (isEmbedded) {
+        // Just create the base class for state tracking and link updates
+        new SharingBase(layout);
+    } else {
+        // Create full Sharing with all features
+        new Sharing(layout);
+    }
+}