Issue 5028 - Use browser namespace

polyfill.js

Index: polyfill.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/polyfill.js
@@ -0,0 +1,140 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-present eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+"use strict";
+
+(function()
+{
+  window.browser = {};
+
+  /* I18n */
+
+  let getLocaleCandidates = function(selectedLocale)
+  {
+    let candidates = [];
+    let defaultLocale = "en_US";
+
+    // e.g. "ja-jp-mac" -> "ja_JP", note that the part after the second
+    // dash is dropped, since we only support language and region
+    let parts = selectedLocale.split("-");
+    let language = parts[0];
+    let region = (parts[1] || "").toUpperCase();
+
+    if (region)
+      candidates.push(language + "_" + region);
+
+    candidates.push(language);
+
+    if (candidates.indexOf(defaultLocale) == -1)
+      candidates.push(defaultLocale);
+
+    return candidates;
+  };
+
+  let selectedLocale = window.navigator.language;
+  let match = /[?&]locale=([\w-]+)/.exec(window.location.search);
+  if (match)
+    selectedLocale = match[1];
+
+  let locales = getLocaleCandidates(selectedLocale);
+  let catalog = Object.create(null);
+  let catalogFile = window.location.pathname.replace(/.*\//, "")
+    .replace(/\..*/, "") + ".json";
+
+  let replacePlaceholder = function(text, placeholder, content)
+  {
+    return text.split("$" + placeholder + "$").join(content || "");
+  };
+
+  let parseMessage = function(rawMessage)
+  {
+    let text = rawMessage.message;
+    let placeholders = [];
+
+    for (let placeholder in rawMessage.placeholders)
+    {
+      let {content} = rawMessage.placeholders[placeholder];
+
+      if (/^\$\d+$/.test(content))
+        placeholders[parseInt(content.substr(1), 10) - 1] = placeholder;
+      else
+        text = replacePlaceholder(text, placeholder, content);
+    }
+
+    return [text, placeholders];
+  };
+
+  let readCatalog = function(locale, file)
+  {
+    let xhr = new XMLHttpRequest();
+    xhr.open("GET", "locale/" + locale + "/" + file, false);
+    xhr.overrideMimeType("text/plain");
+
+    try
+    {
+      xhr.send();
+    }
+    catch (e)
+    {
+      return;
+    }
+
+    if (xhr.status != 200 && xhr.status != 0)
+      return;
+
+    let rawCatalog = JSON.parse(xhr.responseText);
+    for (let msgId in rawCatalog)
+    {
+      if (!(msgId in catalog))
+        catalog[msgId] = parseMessage(rawCatalog[msgId]);
+    }
+  };
+
+  browser.i18n = {
+    getUILanguage()
+    {
+      return locales[0].replace(/_/g, "-");
+    },
+    getMessage(msgId, substitutions)
+    {
+      while (true)
+      {
+        let message = catalog[msgId];
+        if (message)
+        {
+          let text = message[0];
+          let placeholders = message[1];
+
+          if (!(substitutions instanceof Array))
+            substitutions = [substitutions];
+
+          for (let i = 0; i < placeholders.length; i++)
+            text = replacePlaceholder(text, placeholders[i], substitutions[i]);
+
+          return text;
+        }
+
+        if (locales.length == 0)
+          return "";
+
+        let locale = locales.shift();
+        readCatalog(locale, "common.json");
+        readCatalog(locale, catalogFile);
+      }
+    }
+  };
+}());