tor-browser

commit b2af3a310ae175656f65dac464d017d508d69860
parent 97fb70153d00ad3c4d5b4b9b15083638331dbdd8
Author: Mark Striemer <mstriemer@mozilla.com>
Date:   Sat, 29 Nov 2025 05:53:03 +0000

Bug 2002380 - AsyncSetting callback hook before caching setting values r=mconley,mtigley

Provide a way for AsyncSettings to start work to be used in this
callback refresh cycle.

Differential Revision: https://phabricator.services.mozilla.com/D274041

Diffstat:
M
browser/components/preferences/main.js
 | 
13
++++++++++++-
M
toolkit/content/preferences/AsyncSetting.mjs
 | 
20
++++++++++++++++++++

2 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/browser/components/preferences/main.js b/browser/components/preferences/main.js
@@ -1317,6 +1317,13 @@ Preferences.addSetting(
   class extends Preferences.AsyncSetting {
     static id = "payments-list";
 
+    /** @type {Promise<any[]>} */
+    paymentMethods;
+
+    beforeRefresh() {
+      this.paymentMethods = this.getPaymentMethods();
+    }
+
     async getPaymentMethods() {
       await FormAutofillPreferences.prototype.initializePaymentsStorage();
       return FormAutofillPreferences.prototype.makePaymentsListItems();
@@ -1324,10 +1331,14 @@ Preferences.addSetting(
 
     async getControlConfig() {
       return {
-        items: await this.getPaymentMethods(),
+        items: await this.paymentMethods,
       };
     }
 
+    async visible() {
+      return Boolean((await this.paymentMethods).length);
+    }
+
     setup() {
       Services.obs.addObserver(this.emitChange, "formautofill-storage-changed");
       return () =>
diff --git a/toolkit/content/preferences/AsyncSetting.mjs b/toolkit/content/preferences/AsyncSetting.mjs
@@ -44,6 +44,25 @@ export class AsyncSetting extends EventEmitter {
   setup() {}
 
   /**
+   * Called before the setting values will be cached. You can start any shared
+   * work here if you need the same value in multiple callbacks.
+   *
+   * @example
+   * class Attendees extends AsyncSetting {
+   *   beforeRefresh() {
+   *     this.attendees = MeetingDb.getAttendees();
+   *   }
+   *   get() {
+   *     return this.attendees;
+   *   }
+   *   async visible() {
+   *     return (await this.attendees).length;
+   *   }
+   * }
+   */
+  beforeRefresh() {}
+
+  /**
    * Get the value of this setting.
    *
    * @abstract
@@ -171,6 +190,7 @@ export class AsyncSettingHandler {
    * Called to trigger async tasks and re-cache values.
    */
   async refresh() {
+    this.asyncSetting.beforeRefresh();
     [
       this.cachedValue,
       this.cachedDisabled,