/Framework/ext-4.0.7/src/core/src/lang/Error.js

/*

This file is part of Ext JS 4

Copyright (c) 2011 Sencha Inc

Contact:  http://www.sencha.com/contact

Commercial Usage
Licensees holding valid commercial licenses may use this file in accordance with the Commercial Software License Agreement provided with the Software or, alternatively, in accordance with the terms contained in a written agreement between you and Sencha.

If you are unsure which license is appropriate for your use, please contact the sales department at http://www.sencha.com/contact.

*/
/**
 * @author Brian Moeskau <brian@sencha.com>
 * @docauthor Brian Moeskau <brian@sencha.com>
 *
 * A wrapper class for the native JavaScript Error object that adds a few useful capabilities for handling
 * errors in an Ext application. When you use Ext.Error to {@link #raise} an error from within any class that
 * uses the Ext 4 class system, the Error class can automatically add the source class and method from which
 * the error was raised. It also includes logic to automatically log the eroor to the console, if available,
 * with additional metadata about the error. In all cases, the error will always be thrown at the end so that
 * execution will halt.
 *
 * Ext.Error also offers a global error {@link #handle handling} method that can be overridden in order to
 * handle application-wide errors in a single spot. You can optionally {@link #ignore} errors altogether,
 * although in a real application it's usually a better idea to override the handling function and perform
 * logging or some other method of reporting the errors in a way that is meaningful to the application.
 *
 * At its simplest you can simply raise an error as a simple string from within any code:
 *
 * Example usage:
 *
 *     Ext.Error.raise('Something bad happened!');
 *
 * If raised from plain JavaScript code, the error will be logged to the console (if available) and the message
 * displayed. In most cases however you'll be raising errors from within a class, and it may often be useful to add
 * additional metadata about the error being raised.  The {@link #raise} method can also take a config object.
 * In this form the `msg` attribute becomes the error description, and any other data added to the config gets
 * added to the error object and, if the console is available, logged to the console for inspection.
 *
 * Example usage:
 *
 *     Ext.define('Ext.Foo', {
 *         doSomething: function(option){
 *             if (someCondition === false) {
 *                 Ext.Error.raise({
 *                     msg: 'You cannot do that!',
 *                     option: option,   // whatever was passed into the method
 *                     'error code': 100 // other arbitrary info
 *                 });
 *             }
 *         }
 *     });
 *
 * If a console is available (that supports the `console.dir` function) you'll see console output like:
 *
 *     An error was raised with the following data:
 *     option:         Object { foo: "bar"}
 *         foo:        "bar"
 *     error code:     100
 *     msg:            "You cannot do that!"
 *     sourceClass:   "Ext.Foo"
 *     sourceMethod:  "doSomething"
 *
 *     uncaught exception: You cannot do that!
 *
 * As you can see, the error will report exactly where it was raised and will include as much information as the
 * raising code can usefully provide.
 *
 * If you want to handle all application errors globally you can simply override the static {@link #handle} method
 * and provide whatever handling logic you need. If the method returns true then the error is considered handled
 * and will not be thrown to the browser. If anything but true is returned then the error will be thrown normally.
 *
 * Example usage:
 *
 *     Ext.Error.handle = function(err) {
 *         if (err.someProperty == 'NotReallyAnError') {
 *             // maybe log something to the application here if applicable
 *             return true;
 *         }
 *         // any non-true return value (including none) will cause the error to be thrown
 *     }
 *
 */
Ext.Error = Ext.extend(Error, {
    statics: {
        /**
         * @property {Boolean} ignore
         * Static flag that can be used to globally disable error reporting to the browser if set to true
         * (defaults to false). Note that if you ignore Ext errors it's likely that some other code may fail
         * and throw a native JavaScript error thereafter, so use with caution. In most cases it will probably
         * be preferable to supply a custom error {@link #handle handling} function instead.
         *
         * Example usage:
         *
         *     Ext.Error.ignore = true;
         *
         * @static
         */
        ignore: false,

        /**
         * @property {Boolean} notify
         * Static flag that can be used to globally control error notification to the user. Unlike
         * Ex.Error.ignore, this does not effect exceptions. They are still thrown. This value can be
         * set to false to disable the alert notification (default is true for IE6 and IE7).
         *
         * Only the first error will generate an alert. Internally this flag is set to false when the
         * first error occurs prior to displaying the alert.
         *
         * This flag is not used in a release build.
         *
         * Example usage:
         *
         *     Ext.Error.notify = false;
         *
         * @static
         */
        //notify: Ext.isIE6 || Ext.isIE7,

        /**
         * Raise an error that can include additional data and supports automatic console logging if available.
         * You can pass a string error message or an object with the `msg` attribute which will be used as the
         * error message. The object can contain any other name-value attributes (or objects) to be logged
         * along with the error.
         *
         * Note that after displaying the error message a JavaScript error will ultimately be thrown so that
         * execution will halt.
         *
         * Example usage:
         *
         *     Ext.Error.raise('A simple string error message');
         *
         *     // or...
         *
         *     Ext.define('Ext.Foo', {
         *         doSomething: function(option){
         *             if (someCondition === false) {
         *                 Ext.Error.raise({
         *                     msg: 'You cannot do that!',
         *                     option: option,   // whatever was passed into the method
         *                     'error code': 100 // other arbitrary info
         *                 });
         *             }
         *         }
         *     });
         *
         * @param {String/Object} err The error message string, or an object containing the attribute "msg" that will be
         * used as the error message. Any other data included in the object will also be logged to the browser console,
         * if available.
         * @static
         */
        raise: function(err){
            err = err || {};
            if (Ext.isString(err)) {
                err = { msg: err };
            }

            var method = this.raise.caller;

            if (method) {
                if (method.$name) {
                    err.sourceMethod = method.$name;
                }
                if (method.$owner) {
                    err.sourceClass = method.$owner.$className;
                }
            }

            if (Ext.Error.handle(err) !== true) {
                var msg = Ext.Error.prototype.toString.call(err);

                Ext.log({
                    msg: msg,
                    level: 'error',
                    dump: err,
                    stack: true
                });

                throw new Ext.Error(err);
            }
        },

        /**
         * Globally handle any Ext errors that may be raised, optionally providing custom logic to
         * handle different errors individually. Return true from the function to bypass throwing the
         * error to the browser, otherwise the error will be thrown and execution will halt.
         *
         * Example usage:
         *
         *     Ext.Error.handle = function(err) {
         *         if (err.someProperty == 'NotReallyAnError') {
         *             // maybe log something to the application here if applicable
         *             return true;
         *         }
         *         // any non-true return value (including none) will cause the error to be thrown
         *     }
         *
         * @param {Ext.Error} err The Ext.Error object being raised. It will contain any attributes that were originally
         * raised with it, plus properties about the method and class from which the error originated (if raised from a
         * class that uses the Ext 4 class system).
         * @static
         */
        handle: function(){
            return Ext.Error.ignore;
        }
    },

    // This is the standard property that is the name of the constructor.
    name: 'Ext.Error',

    /**
     * Creates new Error object.
     * @param {String/Object} config The error message string, or an object containing the
     * attribute "msg" that will be used as the error message. Any other data included in
     * the object will be applied to the error instance and logged to the browser console, if available.
     */
    constructor: function(config){
        if (Ext.isString(config)) {
            config = { msg: config };
        }

        var me = this;

        Ext.apply(me, config);

        me.message = me.message || me.msg; // 'message' is standard ('msg' is non-standard)
        // note: the above does not work in old WebKit (me.message is readonly) (Safari 4)
    },

    /**
     * Provides a custom string representation of the error object. This is an override of the base JavaScript
     * `Object.toString` method, which is useful so that when logged to the browser console, an error object will
     * be displayed with a useful message instead of `[object Object]`, the default `toString` result.
     *
     * The default implementation will include the error message along with the raising class and method, if available,
     * but this can be overridden with a custom implementation either at the prototype level (for all errors) or on
     * a particular error instance, if you want to provide a custom description that will show up in the console.
     * @return {String} The error message. If raised from within the Ext 4 class system, the error message will also
     * include the raising class and method names, if available.
     */
    toString: function(){
        var me = this,
            className = me.className ? me.className  : '',
            methodName = me.methodName ? '.' + me.methodName + '(): ' : '',
            msg = me.msg || '(No description provided)';

        return className + methodName + msg;
    }
});

/*
 * This mechanism is used to notify the user of the first error encountered on the page. This
 * was previously internal to Ext.Error.raise and is a desirable feature since errors often
 * slip silently under the radar. It cannot live in Ext.Error.raise since there are times
 * where exceptions are handled in a try/catch.
 */
//<debug>
(function () {
    var prevOnError, timer, errors = 0,
        extraordinarilyBad = /(out of stack)|(too much recursion)|(stack overflow)|(out of memory)/i,
        win = Ext.global;

    if (typeof window === 'undefined') {
        return; // build system or some such environment...
    }

    // This method is called to notify the user of the current error status.
    function notify () {
        var counters = Ext.log.counters,
            supports = Ext.supports,
            hasOnError = supports && supports.WindowOnError; // TODO - timing

        // Put log counters to the status bar (for most browsers):
        if (counters && (counters.error + counters.warn + counters.info + counters.log)) {
            var msg = [ 'Logged Errors:',counters.error, 'Warnings:',counters.warn,
                        'Info:',counters.info, 'Log:',counters.log].join(' ');
            if (errors) {
                msg = '*** Errors: ' + errors + ' - ' + msg;
            } else if (counters.error) {
                msg = '*** ' + msg;
            }
            win.status = msg;
        }

        // Display an alert on the first error:
        if (!Ext.isDefined(Ext.Error.notify)) {
            Ext.Error.notify = Ext.isIE6 || Ext.isIE7; // TODO - timing
        }
        if (Ext.Error.notify && (hasOnError ? errors : (counters && counters.error))) {
            Ext.Error.notify = false;

            if (timer) {
                win.clearInterval(timer); // ticks can queue up so stop...
                timer = null;
            }

            alert('Unhandled error on page: See console or log');
            poll();
        }
    }

    // Sets up polling loop. This is the only way to know about errors in some browsers
    // (Opera/Safari) and is the only way to update the status bar for warnings and other
    // non-errors.
    function poll () {
        timer = win.setInterval(notify, 1000);
    }

    // window.onerror sounds ideal but it prevents the built-in error dialog from doing
    // its (better) thing.
    poll();
})();
//</debug>