wiring up messaging

Author: Shane Osbourne

packages/messaging/lib/webkit.js

@@ -10,7 +10,7 @@
  */
 // eslint-disable-next-line @typescript-eslint/no-unused-vars
 import { MessagingTransport, MissingHandler } from '../index.js'
-import { isResponseFor } from '../schema.js'
+import { isResponseFor, isSubscriptionEventFor } from '../schema.js'
 
 /**
  * @example
@@ -293,9 +293,25 @@ export class WebkitMessagingTransport {
      * @param {(value: unknown) => void} callback
      */
     subscribe (msg, callback) {
-        console.warn('webkit.subscribe is not implemented yet!', msg, callback)
+        // for now, bail if there's already a handler setup for this subscription
+        if (msg.subscriptionName in this.globals.window) {
+            throw new this.globals.Error(`A subscription with the name ${msg.subscriptionName} already exists`)
+        }
+        this.globals.ObjectDefineProperty(this.globals.window, msg.subscriptionName, {
+            enumerable: false,
+            configurable: true,
+            writable: false,
+            value: (data) => {
+                if (data && isSubscriptionEventFor(msg, data)) {
+                    callback(data.params)
+                } else {
+                    console.warn('Received a message that did not match the subscription', data)
+                }
+            }
+        })
         return () => {
-            console.log('teardown')
+            console.log('...tear down if the subscription is cancelled')
+            this.globals.ReflectDeleteProperty(this.globals.window, msg.subscriptionName)
         }
     }
 }
@@ -406,6 +422,8 @@ function captureGlobals () {
         JSONparse: window.JSON.parse,
         Arrayfrom: window.Array.from,
         Promise: window.Promise,
+        Error: window.Error,
+        ReflectDeleteProperty: window.Reflect.deleteProperty.bind(window.Reflect),
         ObjectDefineProperty: window.Object.defineProperty,
         addEventListener: window.addEventListener.bind(window),
         /** @type {Record<string, any>} */

packages/messaging/schema.js

@@ -195,3 +195,18 @@ export function isResponseFor (request, data) {
     }
     return false
 }
+
+/**
+ * @param {Subscription} sub
+ * @param {Record<string, any>} data
+ * @return {data is SubscriptionEvent}
+ */
+export function isSubscriptionEventFor (sub, data) {
+    if ('subscriptionName' in data) {
+        return data.featureName === sub.featureName &&
+            data.context === sub.context &&
+            data.subscriptionName === sub.subscriptionName
+    }
+
+    return false
+}

packages/special-pages/index.mjs

@@ -122,6 +122,7 @@ for (const buildJob of buildJobs) {
     }
 }
 for (const inlineJob of inlineJobs) {
+    console.log('INLINE:', relative(ROOT, inlineJob.src))
     if (!DRY_RUN) {
         inliner.html({
             fileContent: readFileSync(inlineJob.src, 'utf8'),
@@ -131,7 +132,6 @@ for (const inlineJob of inlineJobs) {
             if (error) {
                 return exitWithErrors([error])
             }
-            console.log('INLINE:', relative(ROOT, inlineJob.src))
             writeFileSync(inlineJob.src, result)
         })
     }

packages/special-pages/pages/duckplayer/src/js/index.js

@@ -23,7 +23,8 @@
  * #### Messages:
  *
  * On Page Load
- *   - {@link DuckPlayerPageMessages.onUserValuesChanged} begins immediately. It expects an initial value, and then will continue to listen for updates
+ *   - {@link DuckPlayerPageMessages.getUserValues} is initially called to get the current settings
+ *   - {@link DuckPlayerPageMessages.onUserValuesChanged} subscription begins immediately - it will continue to listen for updates
  *
  * Then the following message can be sent at any time
  *   - {@link DuckPlayerPageMessages.setUserValues}
@@ -33,7 +34,7 @@
 import {
     Messaging,
     WindowsMessagingConfig,
-    MessagingContext, TestTransportConfig
+    MessagingContext, TestTransportConfig, WebkitMessagingConfig
 } from '../../../../../messaging/index.js'
 import { DuckPlayerPageMessages, UserValues } from './messages'
 import { html } from '../../../../../../src/dom-utils'
@@ -347,6 +348,14 @@ const Comms = {
             })
             const messaging = new Messaging(messageContext, opts)
             Comms.messaging = new DuckPlayerPageMessages(messaging)
+        } else if (opts.platform === 'apple') {
+            const opts = new WebkitMessagingConfig({
+                hasModernWebkitAPI: true,
+                secret: '',
+                webkitMessageHandlerNames: ['specialPages']
+            })
+            const messaging = new Messaging(messageContext, opts)
+            Comms.messaging = new DuckPlayerPageMessages(messaging)
         } else if (opts.platform === 'integration') {
             const config = new TestTransportConfig({
                 notify (msg) {

src/globals.d.ts

@@ -14,7 +14,7 @@ declare namespace contentScopeFeatures {
  */
 interface ImportMeta {
     env: 'production' | 'development'
-    platform?: 'windows' | 'integration'
+    platform?: 'windows' | 'integration' | 'apple'
     injectName?: string
 }