feat: init and fork some code from angular-auth-oidc-client

src/iframe/existing-iframe.service.ts

@@ -0,0 +1,75 @@
+import { DOCUMENT } from '../../dom';
+import { inject, Injectable } from 'injection-js';
+import { OpenIdConfiguration } from '../config/openid-configuration';
+import { LoggerService } from '../logging/logger.service';
+
+@Injectable()
+export class IFrameService {
+  private readonly document = inject(DOCUMENT);
+
+  private readonly loggerService = inject(LoggerService);
+
+  getExistingIFrame(identifier: string): HTMLIFrameElement | null {
+    const iFrameOnParent = this.getIFrameFromParentWindow(identifier);
+
+    if (this.isIFrameElement(iFrameOnParent)) {
+      return iFrameOnParent;
+    }
+
+    const iFrameOnSelf = this.getIFrameFromWindow(identifier);
+
+    if (this.isIFrameElement(iFrameOnSelf)) {
+      return iFrameOnSelf;
+    }
+
+    return null;
+  }
+
+  addIFrameToWindowBody(
+    identifier: string,
+    config: OpenIdConfiguration
+  ): HTMLIFrameElement {
+    const sessionIframe = this.document.createElement('iframe');
+
+    sessionIframe.id = identifier;
+    sessionIframe.title = identifier;
+    this.loggerService.logDebug(config, sessionIframe);
+    sessionIframe.style.display = 'none';
+    this.document.body.appendChild(sessionIframe);
+
+    return sessionIframe;
+  }
+
+  private getIFrameFromParentWindow(
+    identifier: string
+  ): HTMLIFrameElement | null {
+    try {
+      const iFrameElement =
+        this.document.defaultView?.parent.document.getElementById(identifier);
+
+      if (this.isIFrameElement(iFrameElement)) {
+        return iFrameElement;
+      }
+
+      return null;
+    } catch (e) {
+      return null;
+    }
+  }
+
+  private getIFrameFromWindow(identifier: string): HTMLIFrameElement | null {
+    const iFrameElement = this.document.getElementById(identifier);
+
+    if (this.isIFrameElement(iFrameElement)) {
+      return iFrameElement;
+    }
+
+    return null;
+  }
+
+  private isIFrameElement(
+    element: HTMLElement | null | undefined
+  ): element is HTMLIFrameElement {
+    return !!element && element instanceof HTMLIFrameElement;
+  }
+}