port.js

// Chrome to Safari port
// Author: Michael Gundlach (gundlach@gmail.com)
// License: GPLv3 as part of code.getadblock.com
//          or MIT if GPLv3 conflicts with your code's license.
//
// Porting library to make Chrome extensions work in Safari.
// To use: Add as the first script loaded in your Options page,
// your background page, your Chrome manifest.json, and your
// Safari Info.plist (created by the Extensions Builder).
//
// Then you can use chrome.* APIs as usual, and check the SAFARI
// global boolean variable to see if you're in Safari or Chrome
// for doing browser-specific stuff.  The safari.* APIs will
// still be available in Safari, and the chrome.* APIs will be
// unchanged in Chrome.

if (typeof SAFARI == "undefined") {
(function() {

// True in Safari, false in Chrome.
SAFARI = (function() {
  if (typeof safari === "undefined" && typeof chrome === "undefined") {
    // Safari bug: window.safari undefined in iframes with JS src in them.
    // Must get it from an ancestor.
    var w = window;
    while (w.safari === undefined && w !== window.top) {
      w = w.parent;
    }
    window.safari = w.safari;
  }
  return (typeof safari !== "undefined");
})();

// Safari 5.0 (533.x.x) with no menu support
LEGACY_SAFARI = SAFARI && (navigator.appVersion.match(/\sSafari\/(\d+)\./) || [null,0])[1] < 534;
// Safari 5.1 (534.x.x) with no undo support
LEGACY_SAFARI_51 = SAFARI && (navigator.appVersion.match(/\sSafari\/(\d+)\./) || [null,0])[1] <= 534;

if (SAFARI) {

  var isOnGlobalPage = !!safari.extension.bars;

  // Return the object on which you can add/remove event listeners.
  // If there isn't one, don't explode.
  var listeningContext = function() {
    if (safari.self && safari.self.addEventListener)
      return safari.self;
    if (safari.application && safari.application.addEventListener)
      return safari.application;
    console.log("No add/remove event listener possible at this location!");
    console.trace();
    return {
      addEventListener: function() {},
      removeEventListener: function() {}
    };
  };
  var listenFor = function(messageName, handler) {
    var listener = function(messageEvent) {
      if (messageEvent.name == messageName)
        handler(messageEvent);
    };
    listeningContext().addEventListener("message", listener, false);
    return listener;
  };
  var removeListener = function(listener) {
    listeningContext().removeEventListener("message", listener, false);
  };
  // Return the object on which you can dispatch messages -- globally, or on the
  // messageEvent if specified.  If there isn't one, don't explode.
  // Make this globally available (don't use 'var') as it is used outside port.js
  dispatchContext = function(messageEvent) {
    // Can we dispatch on the messageEvent target?
    var m = messageEvent;
    if (m && m.target && m.target.page && m.target.page.dispatchMessage)
      return m.target.page;
    // Are we in some context where safari.self works, whatever that is?
    var s = safari.self;
    if (s && s.tab && s.tab.dispatchMessage)
      return s.tab;
    // Are we in the global page sending to the active tab?
    var b = (safari.application && safari.application.activeBrowserWindow);
    var p = (b && b.activeTab && b.activeTab.page);
    if (p && p.dispatchMessage)
      return p;
    console.log("No dispatchMessage possible at this location!");
    console.trace();
    return {
      dispatchMessage: function(msg, data) {
        console.warn("Failed to call dispatchMessage(", msg, ",", data, ")");
        console.trace();
      }
    };
  };

  // Replace the 'chrome' object with a Safari adapter.
  chrome = {
    extension: {
      getBackgroundPage: function() {
        return safari.extension.globalPage.contentWindow;
      },

      getURL: function(path) {
        return safari.extension.baseURI + path;
      },

      sendRequest: (function() {
        // Where to call .dispatchMessage() when sendRequest is called.
        var dispatchTargets = [];
        if (!isOnGlobalPage) {
          // In a non-global context, the dispatch target is just the local
          // object that lets you call .dispatchMessage().
          dispatchTargets.push(dispatchContext());
        }
        else {
          // In the global context, we must call .dispatchMessage() wherever
          // someone has called .onRequest().  There's no good way to get at
          // them directly, though, so .onRequest calls *us*, so we get access
          // to a messageEvent object that points to their page that we can
          // call .dispatchMessage() upon.
          listenFor("onRequest registration", function(messageEvent) {
            var context = dispatchContext(messageEvent);
            if (dispatchTargets.indexOf(context) == -1)
              dispatchTargets.push(context);
          });
        }

        // Dispatches a request to a list of recipients.  Calls the callback
        // only once, using the first response received from any recipient.
        function theFunction(data, callback) {
          var callbackToken = "callback" + Math.random();

          // Dispatch to each recipient.
          dispatchTargets.forEach(function(target) {
            var message = {
              data: data,
              frameInfo: chrome._tabInfo.gatherFrameInfo(),
              callbackToken: callbackToken
            };
            target.dispatchMessage("request", message);
          });

          // Listen for a response.  When we get it, call the callback and stop
          // listening.
          var listener = listenFor("response", function(messageEvent) {
            if (messageEvent.message.callbackToken != callbackToken)
              return;
            // Must wrap this call in a timeout to avoid crash, per Safari team
            window.setTimeout(function() {
              removeListener(listener);
            }, 0);
            if (callback)
              callback(messageEvent.message.data);
          });
        }
        return theFunction;
      })(),

      onRequest: {
        addListener: function(handler) {
          // If listening for requests from the global page, we must call the
          // global page so it can get a messageEvent through which to send
          // requests to us.
          if (!isOnGlobalPage)
            dispatchContext().dispatchMessage("onRequest registration", {});

          listenFor("request", function(messageEvent) {
            var request = messageEvent.message.data;

            var sender = {}; // Empty in onRequest in non-global contexts.
            if (isOnGlobalPage) { // But filled with sender data otherwise.
              var tab = messageEvent.target;
              var frameInfo = messageEvent.message.frameInfo;
              chrome._tabInfo.notice(tab, frameInfo);
              sender.tab = chrome._tabInfo.info(tab, frameInfo.visible);
              // Filled with URL of frame.
              sender.url = frameInfo.url;
            }

            var sendResponse = function(dataToSend) {
              var responseMessage = { callbackToken: messageEvent.message.callbackToken, data: dataToSend };
              dispatchContext(messageEvent).dispatchMessage("response", responseMessage);
            };
            handler(request, sender, sendResponse);
          });
        }
      },

      onRequestExternal: {
        addListener: function() {
          // CHROME PORT LIBRARY: onRequestExternal not supported.
        }
      }
    },

    runtime: {
        getManifest: function() {
            var xhr = new XMLHttpRequest();
            xhr.open("GET", chrome.extension.getURL("manifest.json"), false);
            xhr.send();
            var object = JSON.parse(xhr.responseText);
            return object;
        }
    },

    // Helper object to ensure that tabs sending requests to the global page
    // get some extra attributes for the global page to use:
    //   id: an ID assigned by us so we can refer to the tab by ID elsewhere.
    //   visible_url: the URL of the top-level frame in the tab, if any.
    //   invisible_url: the URL of the top-level frame in the invisible page
    //                  being preloaded by the tab, if any (new in Safari 6.1).
    //
    // We are forced to store the *_url properties because the Safari API
    // doesn't currently give us a messageEvent.target.page.url property.  See
    // Issue #29.
    _tabInfo: {
      // Returns an object that can be passed to chrome._tabInfo.notice().
      //
      // Called by a frame sending a request to the global page.
      gatherFrameInfo: function() {
        return {
          visible: !document.hidden,
          top_level: (window === window.top),
          url: document.location.href
        };
      },

      // Tab objects are destroyed when no one has a reference to them, so we
      // keep a list of them, lest our data get lost.
      _tabs: [],
      _lastAssignedTabId: 0,

      // Ensure |tab| has a .id property assigned, and possibly update its
      // |visible_url| or |invisible_url| property.
      //
      // info is an object passed from the requesting frame, containing
      //   visible: whether the frame is on a visible or preloading page
      //   url: url of the frame
      //   top_level: true if the frame is top level in its page
      //
      // Called by the global page.
      notice: function(tab, info) {
        // Clean up closed tabs, to avoid memory bloat.
        this._tabs = this._tabs.filter(function(t) { return t.browserWindow != null; });

        if (tab.id == undefined) {
          // New tab
          tab.id = this._lastAssignedTabId + 1;
          this._lastAssignedTabId = tab.id;
          this._tabs.push(tab); // save so it isn't garbage collected, losing our data.
        }

        if (info.top_level) {
          tab[info.visible ? 'visible_url' : 'invisible_url'] = getUnicodeUrl(info.url);
        }
      },

      // Return an {id, url} object for the given tab's top level frame if
      // visible is true, or the given tab's preloaded page's top level frame,
      // if visible is false.  Assumes this.notice() has been called for every
      // request from a frame to the global page.
      //
      // Called by the global page.
      info: function(tab, visible) {
        return {
          id: tab.id,
          url: (visible ? getUnicodeUrl(tab.visible_url) : getUnicodeUrl(tab.invisible_url))
        };
      }
    },

    i18n: (function() {

      function syncFetch(file, fn) {
        var xhr = new XMLHttpRequest();
        xhr.open("GET", chrome.extension.getURL(file), false);
        xhr.onreadystatechange = function() {
          if(this.readyState == 4 && this.responseText != "") {
            fn(this.responseText);
          }
        };
        try {
          xhr.send();
        }
        catch (e) {
          // File not found, perhaps
        }
      }

      // Insert substitution args into a localized string.
      function parseString(msgData, args) {
        // If no substitution, just turn $$ into $ and short-circuit.
        if (msgData.placeholders == undefined && args == undefined)
          return msgData.message.replace(/\$\$/g, '$');

        // Substitute a regex while understanding that $$ should be untouched
        function safesub(txt, re, replacement) {
          var dollaRegex = /\$\$/g, dollaSub = "~~~I18N~~:";
          txt = txt.replace(dollaRegex, dollaSub);
          txt = txt.replace(re, replacement);
          // Put back in "$$" ("$$$$" somehow escapes down to "$$")
          var undollaRegex = /~~~I18N~~:/g, undollaSub = "$$$$";
          txt = txt.replace(undollaRegex, undollaSub);
          return txt;
        }

        var $n_re = /\$([1-9])/g;
        var $n_subber = function(_, num) { return args[num - 1]; };

        var placeholders = {};
        // Fill in $N in placeholders
        for (var name in msgData.placeholders) {
          var content = msgData.placeholders[name].content;
          placeholders[name.toLowerCase()] = safesub(content, $n_re, $n_subber);
        }
        // Fill in $N in message
        var message = safesub(msgData.message, $n_re, $n_subber);
        // Fill in $Place_Holder1$ in message
        message = safesub(message, /\$(\w+?)\$/g, function(full, name) {
          var lowered = name.toLowerCase();
          if (lowered in placeholders)
            return placeholders[lowered];
          return full; // e.g. '$FoO$' instead of 'foo'
        });
        // Replace $$ with $
        message = message.replace(/\$\$/g, '$');

        return message;
      }

      var l10nData = undefined;

      var theI18nObject = {
        // chrome.i18n.getMessage() may be used in any extension resource page
        // without any preparation.  But if you want to use it from a content
        // script in Safari, the content script must first run code like this:
        //
        //   get_localization_data_from_global_page_async(function(data) {
        //     chrome.i18n._setL10nData(data);
        //     // now I can call chrome.i18n.getMessage()
        //   });
        //   // I cannot call getMessage() here because the above call
        //   // is asynchronous.
        //
        // The global page will need to receive your request message, call
        // chrome.i18n._getL10nData(), and return its result.
        //
        // We can't avoid this, because the content script can't load
        // l10n data for itself, because it's not allowed to make the xhr
        // call to load the message files from disk.  Sorry :(
        _getL10nData: function() {
          var result = { locales: [] };

          // == Find all locales we might need to pull messages from, in order
          // 1: The user's current locale, converted to match the format of
          //    the _locales directories (e.g. "en-US" becomes "en_US"
          result.locales.push(navigator.language.replace('-', '_'));
          // 2: Perhaps a region-agnostic version of the current locale
          if (navigator.language.length > 2)
            result.locales.push(navigator.language.substring(0, 2));
          // 3: Set English 'en' as default locale
          if (result.locales.indexOf("en") == -1)
            result.locales.push("en");

          // Load all locale files that exist in that list
          result.messages = {};
          for (var i = 0; i < result.locales.length; i++) {
            var locale = result.locales[i];
            var file = "_locales/" + locale + "/messages.json";
            // Doesn't call the callback if file doesn't exist
            syncFetch(file, function(text) {
              result.messages[locale] = JSON.parse(text);
            });
          }

          return result;
        },

        // Manually set the localization data.  You only need to call this
        // if using chrome.i18n.getMessage() from a content script, before
        // the first call.  You must pass the value of _getL10nData(),
        // which can only be called by the global page.
        _setL10nData: function(data) {
          l10nData = data;
        },

        getMessage: function(messageID, args) {
          if (l10nData == undefined) {
            // Assume that we're not in a content script, because content
            // scripts are supposed to have set l10nData already
            chrome.i18n._setL10nData(chrome.i18n._getL10nData());
          }
          if (typeof args == "string")
            args = [args];
          for (var i = 0; i < l10nData.locales.length; i++) {
            var map = l10nData.messages[l10nData.locales[i]];
            // We must have the locale, and the locale must have the message
            if (map && messageID in map)
              return parseString(map[messageID], args);
          }
          return "";
        }
      };

      return theI18nObject;
    })()

  };
  //the property id is defined here so that we can invoke it without
  //the need for parentheses
  //for example `chrome.runtime.id`
  //should return "com.betafish.adblockforsafari-UAMUU452D9"
  Object.defineProperty(chrome.runtime, "id", {
    get: function() {
      return parseUri(safari.extension.baseURI).host;
    },
    set: undefined
  });
}

})(); } // end if (typeof SAFARI == "undefined") { (function() {