Merge pull request #1379 from kemerava/feature/context-clearing

Context Clearing
Merging to the new branch, will create another PR from that into main

Author: kemerava

CHANGELOG.md

@@ -14,6 +14,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 * Added details of and procedures for resolving fully-qualified appIds and unqualified appIds in the API and Bridging Parts of the Standard. ([#1523](https://github.com/finos/FDC3/pull/1523))
 
+* Added `clearContext` function and associated `contextClearedEvent` to the `Channel` API, to be able to clear specific or all context types from the channel. ([#1379](https://github.com/finos/FDC3/pull/1379))
+
 ### Changed
 
 ### Deprecated
@@ -51,6 +53,18 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 * Added .NET docs for Events to API reference. ([#1441](https://github.com/finos/FDC3/pull/1441))
 * Setup package publishing for mono-repo packages. ([#1520](https://github.com/finos/FDC3/pull/1520))
 * Implementation PR for FDC3 for the Web ([#896](https://github.com/finos/FDC3/pull/896))
+  - resolves ([#1209](https://github.com/finos/FDC3/issues/1209))
+  - resolves ([#1297](https://github.com/finos/FDC3/issues/1297)) 
+  - resolves ([#1429](https://github.com/finos/FDC3/issues/1429)) 
+  - resolves ([#1430](https://github.com/finos/FDC3/issues/1430))
+  - resolves ([#1431](https://github.com/finos/FDC3/issues/1431))
+  - resolves ([#1432](https://github.com/finos/FDC3/issues/1432)) 
+  - resolves ([#1433](https://github.com/finos/FDC3/issues/1433))
+  - resolves ([#1468](https://github.com/finos/FDC3/issues/1468))
+  - resolves ([#810](https://github.com/finos/FDC3/issues/810))
+  - resolves ([#832](https://github.com/finos/FDC3/issues/832))
+  - resolves ([#1487](https://github.com/finos/FDC3/issues/1487))
+  - resolves ([#1488](https://github.com/finos/FDC3/issues/1488))
 * Adjusted reference Desktop Agent implementation for FDC3 for Web to open a new app instance when raiseIntent is called with an appId but no instanceId ([#1556](https://github.com/finos/FDC3/pull/1556))
 
 ### Changed

package-lock.json

@@ -1,13 +1,17 @@
-import { ContextHandler, DisplayMetadata, Listener, Channel } from '@finos/fdc3-standard';
+import { ContextHandler, DisplayMetadata, Listener, Channel, EventHandler } from '@finos/fdc3-standard';
 import { Context } from '@finos/fdc3-context';
 import { Messaging } from '../Messaging';
 import { DefaultContextListener } from '../listeners/DefaultContextListener';
 import {
   BroadcastRequest,
   BroadcastResponse,
+  ClearContextRequest,
+  ClearContextResponse,
   GetCurrentContextRequest,
   GetCurrentContextResponse,
 } from '@finos/fdc3-schema/generated/api/BrowserTypes';
+import { RegisterableListener } from '../listeners/RegisterableListener';
+import { EventListener } from '../listeners/EventListener';
 
 export class DefaultChannel implements Channel {
   protected readonly messaging: Messaging;
@@ -98,4 +102,30 @@ export class DefaultChannel implements Channel {
     await listener.register();
     return listener;
   }
+
+  async clearContext(contextType?: string): Promise<void> {
+    // first, ensure channel state is up-to-date
+    const request: ClearContextRequest = {
+      meta: this.messaging.createMeta(),
+      payload: {
+        channelId: this.id,
+        contextType: contextType ?? null,
+      },
+      type: 'clearContextRequest',
+    };
+    await this.messaging.exchange<ClearContextResponse>(request, 'clearContextResponse', this.messageExchangeTimeout);
+  }
+
+  async addEventListener(type: string | null, handler: EventHandler): Promise<Listener> {
+    let listener: RegisterableListener;
+    switch (type) {
+      case 'contextCleared':
+        listener = new EventListener(this.messaging, 'contextCleared', handler);
+        break;
+      default:
+        throw new Error('Unsupported event type: ' + type);
+    }
+    await listener.register();
+    return listener;
+  }
 }