wisemapping-frontend/packages/core-js/src/index.js

/*
 *    Copyright [2015] [wisemapping]
 *
 *   Licensed under WiseMapping Public License, Version 1.0 (the "License").
 *   It is basically the Apache License, Version 2.0 (the "License") plus the
 *   "powered by wisemapping" text requirement on every single page;
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the license at
 *
 *       http://www.wisemapping.org/license
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

/**
 * Cross-browser implementation of creating an XML document object.
 */
export const createDocument = function () {
    var doc = null;
    if ($defined(window.ActiveXObject)) {
        //http://blogs.msdn.com/b/xmlteam/archive/2006/10/23/using-the-right-version-of-msxml-in-internet-explorer.aspx
        var progIDs = ['Msxml2.DOMDocument.6.0', 'Msxml2.DOMDocument.3.0'];
        for (var i = 0; i < progIDs.length; i++) {
            try {
                doc = new ActiveXObject(progIDs[i]);
                break;
            } catch (ex) {}
        }
    } else if (window.document.implementation && window.document.implementation.createDocument) {
        doc = window.document.implementation.createDocument('', '', null);
    }
    $assert(doc, 'Parser could not be instantiated');

    return doc;
};

/*
 Function: $defined
 Returns true if the passed in value/object is defined, that means is not null or undefined.

 Arguments:
 obj - object to inspect
 */

export const $defined = function (obj) {
    return obj != undefined;
};

export const $assert = function (assert, message) {
    if (!$defined(assert) || !assert) {
        logStackTrace();
        console.log(message);
        throw new Error(message);
    }
};

export const sign = function (value) {
    return value >= 0 ? 1 : -1;
};

export function logStackTrace(exception) {
    if (!$defined(exception)) {
        try {
            throw Error('Unexpected Exception');
        } catch (e) {
            exception = e;
        }
    }
    var result = '';
    if (exception.stack) {
        //Firefox  and Chrome...
        result = exception.stack;
    } else if (window.opera && exception.message) {
        //Opera
        result = exception.message;
    } else {
        //IE and Safari
        result = exception.sourceURL + ': ' + exception.line + '\n\n';

        var currentFunction = arguments.callee.caller;
        while (currentFunction) {
            var fn = currentFunction.toString();
            result = result + '\n' + fn;
            currentFunction = currentFunction.caller;
        }
    }
    window.errorStack = result;
    return result;
}