Bug 1639515 - Part 2: Add mozIntl.DisplayNames. r=platform-i18n-reviewers,gregtatum

Expose `Intl.DisplayNames` to `mozIntl`. The exposed `Intl.DisplayNames` version
supports date-time types, which have been removed from the spec proposal, but
may be re-enabled at some point in the future.

The existing `getDisplayNames` WebIDL function had to be renamed, because WebIDL
doesn't allow specify an attribute named `DisplayNames` and a separate function
called `getDisplayNames`.

Drive-by change:
- Removed an out-dated comment in "mozIMozIntlHelper.idl" which mentioned calling
  `addDateTimeFormatConstructor` twice throws an error.

Differential Revision: https://phabricator.services.mozilla.com/D76114

browser/actors/AboutProtectionsParent.jsm

@@ -390,7 +390,7 @@ class AboutProtectionsParent extends JSWindowActorParent {
         break;
       case "FetchContentBlockingEvents":
         let dataToSend = {};
-        let weekdays = Services.intl.getDisplayNames(undefined, {
+        let weekdays = Services.intl.getDisplayNamesDeprecated(undefined, {
           style: "short",
           keys: [
             "dates/gregorian/weekdays/sunday",

dom/base/IntlUtils.cpp

@@ -69,7 +69,7 @@ void IntlUtils::GetDisplayNames(const Sequence<nsString>& aLocales,
 
   // Now call the method.
   JS::Rooted<JS::Value> retVal(cx);
-  nsresult rv = mozIntl->GetDisplayNames(locales, options, &retVal);
+  nsresult rv = mozIntl->GetDisplayNamesDeprecated(locales, options, &retVal);
   if (NS_FAILED(rv)) {
     aError.Throw(rv);
     return;

toolkit/components/mozintl/MozIntlHelper.cpp

@@ -80,3 +80,26 @@ MozIntlHelper::AddDateTimeFormatConstructor(JS::Handle<JS::Value> val,
 
   return NS_OK;
 }
+
+NS_IMETHODIMP
+MozIntlHelper::AddDisplayNamesConstructor(JS::Handle<JS::Value> val,
+                                          JSContext* cx) {
+  if (!val.isObject()) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // We might be adding this constructor to a Window
+  JS::Rooted<JSObject*> realIntlObj(
+      cx, js::CheckedUnwrapDynamic(&val.toObject(), cx));
+  if (!realIntlObj) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  JSAutoRealm ar(cx, realIntlObj);
+
+  if (!JS::AddMozDisplayNamesConstructor(cx, realIntlObj)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return NS_OK;
+}

toolkit/components/mozintl/mozIMozIntl.idl

@@ -38,7 +38,13 @@
 interface mozIMozIntl : nsISupports
 {
   jsval getCalendarInfo([optional] in jsval locales);
-  jsval getDisplayNames([optional] in jsval locales, [optional] in jsval options);
+
+  /**
+   * Helper for IntlUtils.webidl, will be removed once Intl.DisplayNames
+   * supports date-time types in non-privileged code.
+   */
+  jsval getDisplayNamesDeprecated([optional] in jsval locales, [optional] in jsval options);
+
 
   /**
    * Returns a list of locale codes for a given type.
@@ -79,6 +85,7 @@ interface mozIMozIntl : nsISupports
 
   readonly attribute jsval Collator;
   readonly attribute jsval DateTimeFormat;
+  readonly attribute jsval DisplayNames;
   readonly attribute jsval ListFormat;
   readonly attribute jsval Locale;
   readonly attribute jsval NumberFormat;

toolkit/components/mozintl/mozIMozIntlHelper.idl

@@ -20,9 +20,7 @@ interface mozIMozIntlHelper : nsISupports
   [implicit_jscontext] void addGetDisplayNames(in jsval intlObject);
 
   /**
-   * Adds a MozDateTimeFormat contructor to the given object. This function may only
-   * be called once within a realm/global object: calling it multiple times will
-   * throw.
+   * Adds a MozDateTimeFormat contructor to the given object.
    *
    * The difference between regular Intl.DateTimeFormat and the method created here
    * is that we support two more options:
@@ -41,4 +39,26 @@ interface mozIMozIntlHelper : nsISupports
    * This API should be used everywhere in the UI instead of regular Intl  API.
    */
   [implicit_jscontext] void addDateTimeFormatConstructor(in jsval intlObject);
+
+  /**
+   * Adds a MozDisplayNames contructor to the given object.
+   *
+   * The difference between regular Intl.DisplayNames and the method created here
+   * is that we additionally support the following values for the "type" option:
+   *
+   *    weekday
+   *    month
+   *    quarter
+   *    dayPeriod
+   *
+   * And we additionally support "abbreviated" for the "style" option.
+   *
+   * MozDisplayNames.prototype.of accepts the following inputs for these options:
+   *
+   *    weekday: an integer in the range 1 = Monday to 7 = Sunday.
+   *    month: an integer in the range 1 = January to 13 = Undecimber.
+   *    quarter: an integer in the range 1 to 4.
+   *    dayPeriod: a string from the set {"am", "pm"}.
+   */
+  [implicit_jscontext] void addDisplayNamesConstructor(in jsval intlObject);
 };

toolkit/components/mozintl/mozIntl.jsm

@@ -755,7 +755,7 @@ class MozIntl {
     return this._cache.getCalendarInfo(locales, ...args);
   }
 
-  getDisplayNames(locales, ...args) {
+  getDisplayNamesDeprecated(locales, ...args) {
     if (!this._cache.hasOwnProperty("getDisplayNames")) {
       mozIntlHelper.addGetDisplayNames(this._cache);
     }
@@ -915,6 +915,14 @@ class MozIntl {
 
     return this._cache.MozDateTimeFormat;
   }
+
+  get DisplayNames() {
+    if (!this._cache.hasOwnProperty("DisplayNames")) {
+      mozIntlHelper.addDisplayNamesConstructor(this._cache);
+    }
+
+    return this._cache.DisplayNames;
+  }
 }
 
 MozIntl.prototype.classID = Components.ID(

toolkit/components/mozintl/test/test_mozintl.js

@@ -15,14 +15,15 @@ function run_test() {
 
 function test_methods_presence() {
   equal(Services.intl.getCalendarInfo instanceof Function, true);
-  equal(Services.intl.getDisplayNames instanceof Function, true);
+  equal(Services.intl.getDisplayNamesDeprecated instanceof Function, true);
   equal(Services.intl.getLocaleDisplayNames instanceof Function, true);
 }
 
 function test_methods_calling() {
   Services.intl.getCalendarInfo("pl");
-  Services.intl.getDisplayNames("ar");
+  Services.intl.getDisplayNamesDeprecated("ar");
   new Services.intl.DateTimeFormat("fr");
+  new Services.intl.DisplayNames("fr", { type: "language" });
   new Services.intl.ListFormat("fr");
   new Services.intl.Locale("fr");
   new Services.intl.RelativeTimeFormat("fr");

toolkit/components/mozintl/test/test_mozintlhelper.js

@@ -43,6 +43,7 @@ function test_methods_presence(miHelper) {
   equal(miHelper.addGetCalendarInfo instanceof Function, true);
   equal(miHelper.addGetDisplayNames instanceof Function, true);
   equal(miHelper.addDateTimeFormatConstructor instanceof Function, true);
+  equal(miHelper.addDisplayNamesConstructor instanceof Function, true);
 
   let x = {};
 
@@ -54,4 +55,7 @@ function test_methods_presence(miHelper) {
 
   miHelper.addDateTimeFormatConstructor(x);
   equal(x.DateTimeFormat instanceof Function, true);
+
+  miHelper.addDisplayNamesConstructor(x);
+  equal(x.DisplayNames instanceof Function, true);
 }

toolkit/modules/DateTimePickerPanel.jsm

@@ -293,7 +293,7 @@ var DateTimePickerPanel = class {
   }
 
   getDisplayNames(locale, keys, style) {
-    const displayNames = Services.intl.getDisplayNames(locale, { keys, style });
+    const displayNames = Services.intl.getDisplayNamesDeprecated(locale, { keys, style });
     return keys.map(key => displayNames.values[key]);
   }