brackets/brackets-dist/xorigin.js

/*
 * Copyright (c) 2013 Adobe Systems Incorporated. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 */

/*jslint vars: true, plusplus: true, devel: true, nomen: true, indent: 4, maxerr: 50 */
/*global brackets: true, navigator:true, document:true, window:true */

/**
 * Function to test whether a given error represents an illegal cross origin access
 */
(function () {
    "use strict";

    var testCrossOriginError;

    if (navigator.userAgent.search(" Chrome/") !== -1) {
        // Chrome support
        testCrossOriginError = function (message, url, line) {
            return url === "" && line === 0 && message === "Script error.";
        };
    } else if (navigator.userAgent.slice(0, 6) === 'Opera/') {
        // Opera support
        testCrossOriginError = function (message, url, line) {
            return message === "Uncaught exception: DOMException: NETWORK_ERR";
        };
    }

    // Abort if running in the shell, running on a server or not running in a supported and affected browser
    if (typeof (brackets) !== "undefined" ||
            document.location.href.substr(0, 7) !== "file://" ||
            !testCrossOriginError) {
        return;
    }

    // Remember the current error handler to restore it once we're done
    var previousErrorHandler = window.onerror;

    // Our error handler
    function handleError(message, url, line) {
        // Ignore this error if it does not look like the rather vague cross origin error in Chrome
        // Chrome will print it to the console anyway
        if (!testCrossOriginError(message, url, line)) {
            if (previousErrorHandler) {
                return previousErrorHandler(message, url, line);
            }
            return;
        }

        // Show an error message
        alert("Oops! This application doesn't run in browsers yet.\n\nIt is built in HTML, but right now it runs as a desktop app so you can use it to edit local files. Please use the application shell in the following repo to run this application:\n\ngithub.com/adobe/brackets-shell");

        // Restore the original handler for later errors
        window.onerror = previousErrorHandler;
    }

    // Install our error handler
    window.onerror = handleError;
}());