Expose ngettext() to client-side JS

This exposes the function set by webhelper.set_ngettext() to the client- side Javascript as a ngettext() function, defined on the global window object. This allows apps to translate messages that need to be separated into singular and plural, just like the C ngettext() function. [endlessm/eos-sdk#291]
author: Philip Chimento <philip@endlessm.com> 2015-05-19 13:49:57 -0700
committer: Philip Chimento <philip@endlessm.com> 2015-05-21 13:26:48 -0700
commit: b8d6310bfd7af2cece81c0b7e7fc71711a991871 (patch)
tree: 9059cef91139c3ac5a1cfdb68e242af5692c5f4e
parent: a58f5454c8b046ba4f17534a88db1c19ac22b822 (diff)
4 files changed, 240 insertions, 8 deletions
diff --git a/test/smoke-tests/webhelper/webview2.js b/test/smoke-tests/webhelper/webview2.js
index 03ed560..f50c42d 100644
--- a/test/smoke-tests/webhelper/webview2.js
+++ b/test/smoke-tests/webhelper/webview2.js
@@ -25,6 +25,16 @@ body { \
 </head> \
 \
 <body> \
+<script type="text/javascript"> \
+    window.ngettextButton = (function () { \
+        var times = 0; \
+        return function () { \
+            times++; \
+            var message = ngettext("You have clicked me __ time", "You have clicked me __ times", times); \
+            alert(message.replace("__", times.toString())); \
+        }; \
+    })(); \
+</script> \
 <h1>First page</h1> \
 \
 <p><a href="webhelper://moveToPage?name=page2">Move to page 2</a></p> \
@@ -43,9 +53,12 @@ message from parameter in this URL</a></p> \
 <p>This is text that will be italicized: <span name="translatable">Hello, \
 world!</span></p> \
 \
-<p><button onclick="alert(gettext(\'I came from gettext\'));"> \
-    Click me to use gettext \
-</button></p> \
+<p> \
+    <button onclick="alert(gettext(\'I came from gettext\'));"> \
+        Click me to use gettext \
+    </button> \
+    <button onclick="ngettextButton();">Click me to use ngettext</button> \
+</p> \
 \
 </body> \
 </html>';
@@ -66,6 +79,8 @@ const TestApplication = new Lang.Class({
         this.parent();
 
         this._webhelper.set_gettext((s) => s.italics());
+        this._webhelper.set_ngettext((s, p, n) =>
+            '** ' + (n == 1 ? s : p) + ' **');
         this._webhelper.define_web_actions({
             moveToPage: this.moveToPage.bind(this),
             showMessageFromParameter: this.showMessageFromParameter.bind(this),
diff --git a/test/webhelper/testTranslate2.js b/test/webhelper/testTranslate2.js
index 852c3a1..b34c4cf 100644
--- a/test/webhelper/testTranslate2.js
+++ b/test/webhelper/testTranslate2.js
@@ -63,6 +63,29 @@ describe('WebHelper2 translator', function () {
         expect(webhelper.get_gettext()).toBeNull();
     });
 
+    it('complains about a bad ngettext function', function () {
+        expect(function () {
+            webhelper.set_ngettext('I am not a function');
+        }).toThrow();
+    });
+
+    it('gets and sets the ngettext function', function () {
+        let translation_function = (s, p, n) => n == 1 ? s : p;
+        webhelper.set_ngettext(translation_function);
+        expect(webhelper.get_ngettext()).toBe(translation_function);
+    });
+
+    it('has a null ngettext function by default', function () {
+        expect(webhelper.get_ngettext()).toBeNull();
+    });
+
+    it('can remove the ngettext function by setting null', function () {
+        webhelper.set_ngettext((s, p, n) => n == 1 ? s : p);
+        expect(webhelper.get_ngettext()).not.toBeNull();
+        webhelper.set_ngettext(null);
+        expect(webhelper.get_ngettext()).toBeNull();
+    });
+
     describe('translating a page', function () {
         let webview;
 
@@ -118,18 +141,38 @@ describe('WebHelper2 translator', function () {
     });
 
     describe('used from client-side Javascript', function () {
-        it('translates a string', function (done) {
-            let webview = new WebKit2.WebView();
+        let webview;
+
+        beforeEach(function () {
+            webview = new WebKit2.WebView();
+        });
+
+        function load_script(view, script) {
+            view.load_html('<html><body><script type="text/javascript">' +
+                script + '</script></body></html>', null);
+            Mainloop.run('webhelper2');
+        }
+
+        it('translates a string with gettext()', function (done) {
             let gettext_spy = jasmine.createSpy('gettext_spy').and.callFake((s) => {
                 Mainloop.quit('webhelper2');
                 return s;
             });
             webhelper.set_gettext(gettext_spy);
-            webview.load_html('<html><body><script type="text/javascript">gettext("Translate Me");</script></body></html>',
-                null);
-            Mainloop.run('webhelper2');
+            load_script(webview, 'gettext("Translate Me");');
             expect(gettext_spy).toHaveBeenCalledWith('Translate Me');
             done();
         });
+
+        it('translates a string with ngettext()', function (done) {
+            let ngettext_spy = jasmine.createSpy('ngettext_spy').and.callFake((s, p, n) => {
+                Mainloop.quit('webhelper2');
+                return n == 1 ? s : p;
+            });
+            webhelper.set_ngettext(ngettext_spy);
+            load_script(webview, 'ngettext("File", "Files", 3);');
+            expect(ngettext_spy).toHaveBeenCalledWith('File', 'Files', 3);
+            done();
+        });
     });
 });
diff --git a/webhelper/webextensions/wh2extension.c b/webhelper/webextensions/wh2extension.c
index 48ea9aa..4da7ae4 100644
--- a/webhelper/webextensions/wh2extension.c
+++ b/webhelper/webextensions/wh2extension.c
@@ -2,6 +2,7 @@
 
 /* Copyright 2015 Endless Mobile, Inc. */
 
+#include <math.h>
 #include <string.h>
 
 #include <glib.h>
@@ -78,6 +79,36 @@ translation_function (const gchar *message,
   return retval;
 }
 
+static gchar *
+ngettext_translation_function (const gchar *singular,
+                               const gchar *plural,
+                               gulong       number,
+                               Context     *ctxt)
+{
+  GError *error = NULL;
+  GVariant *result =
+    g_dbus_connection_call_sync (ctxt->connection, ctxt->main_program_name,
+                                 MAIN_PROGRAM_OBJECT_PATH,
+                                 MAIN_PROGRAM_INTERFACE_NAME, "NGettext",
+                                 g_variant_new ("(sst)", singular, plural,
+                                                number),
+                                 (GVariantType *) "(s)",
+                                 G_DBUS_CALL_FLAGS_NO_AUTO_START,
+                                 -1 /* timeout */, NULL /* cancellable */,
+                                 &error);
+  if (result == NULL)
+    {
+      g_warning ("No return value from ngettext: %s", error->message);
+      g_clear_error (&error);
+      return g_strdup (number == 1 ? singular : plural);
+    }
+
+  gchar *retval;
+  g_variant_get (result, "(s)", &retval);
+  g_variant_unref (result);
+  return retval;
+}
+
 static JSValueRef
 gettext_shim (JSContextRef     js,
               JSObjectRef      function,
@@ -123,6 +154,82 @@ gettext_shim (JSContextRef     js,
   return retval;
 }
 
+static JSValueRef
+ngettext_shim (JSContextRef     js,
+               JSObjectRef      function,
+               JSObjectRef      this_object,
+               size_t           n_args,
+               const JSValueRef args[],
+               JSValueRef      *exception)
+{
+  if (n_args != 3)
+    {
+      gchar *errmsg = g_strdup_printf ("Expected three arguments to ngettext(),"
+                                       "but got %d.", n_args);
+      *exception = throw_exception (js, errmsg);
+      g_free (errmsg);
+      return NULL;
+    }
+  if (!JSValueIsString (js, args[0]))
+    {
+      *exception = throw_exception (js, "The first argument to ngettext() "
+                                    "must be a string.");
+      return NULL;
+    }
+  if (!JSValueIsString (js, args[1]))
+    {
+      *exception = throw_exception (js, "The second argument to ngettext() "
+                                    "must be a string.");
+      return NULL;
+    }
+  if (!JSValueIsNumber (js, args[2]))
+    {
+      *exception = throw_exception (js, "The third argument to ngettext() "
+                                    "must be a number.");
+      return NULL;
+    }
+
+  JSObjectRef window = JSContextGetGlobalObject (js);
+  JSStringRef private_name = JSStringCreateWithUTF8CString (PRIVATE_NAME);
+  JSValueRef private_data = JSObjectGetProperty (js, window, private_name,
+                                                 exception);
+  if (JSValueIsUndefined (js, private_data))
+    return NULL;  /* propagate exception */
+  Context *ctxt = (Context *) JSObjectGetPrivate ((JSObjectRef) private_data);
+
+  JSStringRef singular_ref = JSValueToStringCopy (js, args[0], exception);
+  if (singular_ref == NULL)
+    return NULL;  /* propagate exception */
+  gchar *singular_msg = string_ref_to_string (singular_ref);
+  JSStringRelease (singular_ref);
+
+  JSStringRef plural_ref = JSValueToStringCopy (js, args[1], exception);
+  if (plural_ref == NULL)
+    {
+      g_free (singular_msg);
+      return NULL;  /* propagate exception */
+    }
+  gchar *plural_msg = string_ref_to_string (plural_ref);
+  JSStringRelease (plural_ref);
+
+  double number = JSValueToNumber (js, args[2], exception);
+  if (isnan (number))
+    {
+      g_free (singular_msg);
+      g_free (plural_msg);
+      return NULL;  /* propagate exception */
+    }
+
+  gchar *translation = ngettext_translation_function (singular_msg, plural_msg,
+                                                      (gulong) number, ctxt);
+  g_free (singular_msg);
+  g_free (plural_msg);
+
+  JSValueRef retval = string_to_value_ref (js, translation);
+  g_free (translation);
+  return retval;
+}
+
 static void
 translate_html (WebKitDOMDocument *dom,
                 Context           *ctxt)
@@ -298,6 +405,12 @@ on_window_object_cleared (WebKitScriptWorld *script_world,
   if (!set_object_property (js, window, "gettext", (JSValueRef) gettext_func,
                             kJSPropertyAttributeNone))
     return;
+
+  JSObjectRef ngettext_func =
+    JSObjectMakeFunctionWithCallback (js, NULL, ngettext_shim);
+  if (!set_object_property (js, window, "ngettext", (JSValueRef) ngettext_func,
+                            kJSPropertyAttributeNone))
+    return;
 }
 
 static void
diff --git a/webhelper/webhelper2.js b/webhelper/webhelper2.js
index bba4c63..b5f87f8 100644
--- a/webhelper/webhelper2.js
+++ b/webhelper/webhelper2.js
@@ -29,6 +29,12 @@ const WH2_DBUS_MAIN_PROGRAM_INTERFACE = '\
                 <arg name="message" type="s" direction="in"/> \
                 <arg name="translation" type="s" direction="out"/> \
             </method> \
+            <method name="NGettext"> \
+                <arg name="message_singular" type="s" direction="in"/> \
+                <arg name="message_plural" type="s" direction="in"/> \
+                <arg name="number" type="t" direction="in"/> \
+                <arg name="translation" type="s" direction="out"/> \
+            </method> \
         </interface> \
     </node>';
 
@@ -164,6 +170,7 @@ const WebHelper = new Lang.Class({
     _init: function (props={}) {
         this._web_actions = {};
         this._gettext = null;
+        this._ngettext = null;
         this._ProxyConstructor =
             Gio.DBusProxy.makeProxyWrapper(WH2_DBUS_EXTENSION_INTERFACE);
         this.parent(props);
@@ -239,6 +246,10 @@ const WebHelper = new Lang.Class({
         return this._gettext(string);
     },
 
+    NGettext: function (singular, plural, number) {
+        return this._ngettext(singular, plural, number);
+    },
+
     // Public API
 
     /**
@@ -290,6 +301,56 @@ const WebHelper = new Lang.Class({
     },
 
     /**
+     * Method: set_ngettext
+     * Define function which translates singular/plural text
+     *
+     * Parameters:
+     *   ngettext_func - a function, or null
+     *
+     * When you plan to translate text in your web application, set this
+     * property to the translation function.
+     * The function must take three parameters: a string singular message, a
+     * string plural message, and a number for which to generate the message.
+     * The function must return a string.
+     * The canonical example is ngettext().
+     *
+     * This function is made available directly to the browser-side Javascript
+     * as *ngettext()*, a property of the global object.
+     *
+     * Pass null for _ngettext_func_ to unset the translation function.
+     *
+     * If this function has not been called, or has most recently been called
+     * with null, then it is illegal to call *ngettext()* in the client-side
+     * Javascript.
+     *
+     * Example:
+     * > const WebHelper2 = imports.webhelper2;
+     * > const Gettext = imports.gettext;
+     * > const GETTEXT_DOMAIN = 'smoke-grinder';
+     * >
+     * > let webhelper = new WebHelper2.WebHelper('com.example.SmokeGrinder');
+     * > webhelper.set_gettext(Gettext.dngettext.bind(null, GETTEXT_DOMAIN));
+     */
+    set_ngettext: function (ngettext_func) {
+        if (ngettext_func !== null && typeof ngettext_func !== 'function')
+            throw new Error('The translation function must be a function, or ' +
+                'null.');
+        this._ngettext = ngettext_func;
+    },
+
+    /**
+     * Method: get_ngettext
+     * Retrieve the currently set singular/plural translation function
+     *
+     * Returns:
+     *   the translation function previously set with <set_ngettext()>, or null
+     *   if none is currently set.
+     */
+    get_ngettext: function () {
+        return this._ngettext;
+    },
+
+    /**
      * Method: translate_html
      * Translate the HTML page in a webview asynchronously
      *
author	Philip Chimento <philip@endlessm.com>	2015-05-19 13:49:57 -0700
committer	Philip Chimento <philip@endlessm.com>	2015-05-21 13:26:48 -0700
commit	b8d6310bfd7af2cece81c0b7e7fc71711a991871 (patch)
tree	9059cef91139c3ac5a1cfdb68e242af5692c5f4e
parent	a58f5454c8b046ba4f17534a88db1c19ac22b822 (diff)