# Yahoo! UI Library

### console 3.0.0b1

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    /**
     * Console creates a visualization for messages logged through calls to a YUI
     * instance's <code>Y.log( message, category, source )</code> method.  The
     * debug versions of YUI modules will include logging statements to offer some
     * insight into the steps executed during that module's operation.  Including
     * log statements in your code will cause those messages to also appear in the
     * Console.  Use Console to aid in developing your page or application.
     *
     * Entry categories &quot;info&quot;, &quot;warn&quot;, and &quot;error&quot;
     * are also referred to as the log level, and entries are filtered against the
     * configured logLevel.
     *
     * @module console
     * @class Console
     * @extends Widget
     * @param conf {Object} Configuration object (see Configuration attributes)
     * @constructor
     */

    var getCN = Y.ClassNameManager.getClassName,
        CHECKED        = 'checked',
        CLEAR          = 'clear',
        CLICK          = 'click',
        COLLAPSED      = 'collapsed',
        CONSOLE        = 'console',
        CONTENT_BOX    = 'contentBox',
        DISABLED       = 'disabled',
        ENTRY          = 'entry',
        ENTRY_TEMPLATE = 'entryTemplate',
        ERROR          = 'error',
        HEIGHT         = 'height',
        INFO           = 'info',
        INNER_HTML     = 'innerHTML',
        LAST_TIME      = 'lastTime',
        PAUSE          = 'pause',
        PAUSED         = 'paused',
        RESET          = 'reset',
        START_TIME     = 'startTime',
        TITLE          = 'title',
        WARN           = 'warn',

        DOT = '.',

        C_BUTTON           = getCN(CONSOLE,'button'),
        C_CHECKBOX         = getCN(CONSOLE,'checkbox'),
        C_CLEAR            = getCN(CONSOLE,CLEAR),
        C_COLLAPSE         = getCN(CONSOLE,'collapse'),
        C_COLLAPSED        = getCN(CONSOLE,COLLAPSED),
        C_CONSOLE_CONTROLS = getCN(CONSOLE,'controls'),
        C_CONSOLE_HD       = getCN(CONSOLE,'hd'),
        C_CONSOLE_BD       = getCN(CONSOLE,'bd'),
        C_CONSOLE_FT       = getCN(CONSOLE,'ft'),
        C_CONSOLE_TITLE    = getCN(CONSOLE,TITLE),
        C_ENTRY            = getCN(CONSOLE,ENTRY),
        C_ENTRY_CAT        = getCN(CONSOLE,ENTRY,'cat'),
        C_ENTRY_CONTENT    = getCN(CONSOLE,ENTRY,'content'),
        C_ENTRY_META       = getCN(CONSOLE,ENTRY,'meta'),
        C_ENTRY_SRC        = getCN(CONSOLE,ENTRY,'src'),
        C_ENTRY_TIME       = getCN(CONSOLE,ENTRY,'time'),
        C_PAUSE            = getCN(CONSOLE,PAUSE),
        C_PAUSE_LABEL      = getCN(CONSOLE,PAUSE,'label'),

        RE_INLINE_SOURCE = /^(\S+)\s/,
        RE_AMP = /&/g,
        RE_GT  = />/g,
        RE_LT  = /</g,

        ESC_AMP = '&#38;',
        ESC_GT  = '&#62;',
        ESC_LT  = '&#60;',

        L = Y.Lang,
        create     = Y.Node.create,
        isNumber   = L.isNumber,
        isString   = L.isString,
        merge      = Y.merge,
        substitute = Y.substitute;

    function Console() {
        Console.superclass.constructor.apply(this,arguments);
    }

    Y.mix(Console, {

        /**
         * The identity of the widget.
         *
         * @property Console.NAME
         * @type String
         * @static
         */
        NAME : CONSOLE,

        /**
         * Static identifier for logLevel configuration setting to allow all
         * incoming messages to generate Console entries.
         *
         * @property Console.LOG_LEVEL_INFO
         * @type String
         * @static
         */
        LOG_LEVEL_INFO  : INFO,

        /**
         * Static identifier for logLevel configuration setting to allow only
         * incoming messages of logLevel &quot;warn&quot; or &quot;error&quot;
         * to generate Console entries.
         *
         * @property Console.LOG_LEVEL_WARN
         * @type String
         * @static
         */
        LOG_LEVEL_WARN  : WARN,

        /**
         * Static identifier for logLevel configuration setting to allow only
         * incoming messages of logLevel &quot;error&quot; to generate
         * Console entries.
         *
         * @property Console.LOG_LEVEL_ERROR
         * @type String
         * @static
         */
        LOG_LEVEL_ERROR : ERROR,

        /**
         * Map (object) of classNames used to populate the placeholders in the
         * Console.ENTRY_TEMPLATE markup when rendering a new Console entry.
         *
         * <p>By default, the keys contained in the object are:</p>
         * <ul>
         *    <li>entry_class</li>
         *    <li>entry_meta_class</li>
         *    <li>entry_cat_class</li>
         *    <li>entry_src_class</li>
         *    <li>entry_time_class</li>
         *    <li>entry_content_class</li>
         * </ul>
         *
         * @property Console.ENTRY_CLASSES
         * @type Object
         * @static
         */
        ENTRY_CLASSES   : {
            entry_class         : C_ENTRY,
            entry_meta_class    : C_ENTRY_META,
            entry_cat_class     : C_ENTRY_CAT,
            entry_src_class     : C_ENTRY_SRC,
            entry_time_class    : C_ENTRY_TIME,
            entry_content_class : C_ENTRY_CONTENT
        },

        /**
         * Map (object) of classNames used to populate the placeholders in the
         * Console.HEADER_TEMPLATE, Console.BODY_TEMPLATE, and
         * Console.FOOTER_TEMPLATE markup when rendering the Console UI.
         *
         * <p>By default, the keys contained in the object are:</p>
         * <ul>
         *   <li>console_hd_class</li>
         *   <li>console_bd_class</li>
         *   <li>console_ft_class</li>
         *   <li>console_controls_class</li>
         *   <li>console_checkbox_class</li>
         *   <li>console_pause_class</li>
         *   <li>console_pause_label_class</li>
         *   <li>console_button_class</li>
         *   <li>console_clear_class</li>
         *   <li>console_collapse_class</li>
         *   <li>console_title_class</li>
         * </ul>
         *
         * @property Console.CHROME_CLASSES
         * @type Object
         * @static
         */
        CHROME_CLASSES  : {
            console_hd_class       : C_CONSOLE_HD,
            console_bd_class       : C_CONSOLE_BD,
            console_ft_class       : C_CONSOLE_FT,
            console_controls_class : C_CONSOLE_CONTROLS,
            console_checkbox_class : C_CHECKBOX,
            console_pause_class    : C_PAUSE,
            console_pause_label_class : C_PAUSE_LABEL,
            console_button_class   : C_BUTTON,
            console_clear_class    : C_CLEAR,
            console_collapse_class : C_COLLAPSE,
            console_title_class    : C_CONSOLE_TITLE
        },

        /**
         * Markup template used to generate the DOM structure for the header
         * section of the Console when it is rendered.  The template includes
         * these {placeholder}s:
         *
         * <ul>
         *   <li>console_button_class - contributed by Console.CHROME_CLASSES</li>
         *   <li>console_collapse_class - contributed by Console.CHROME_CLASSES</li>
         *   <li>console_hd_class - contributed by Console.CHROME_CLASSES</li>
         *   <li>console_title_class - contributed by Console.CHROME_CLASSES</li>
         *   <li>str_collapse - pulled from attribute strings.collapse</li>
         *   <li>str_title - pulled from attribute strings.title</li>
         * </ul>
         *
         * @property Console.HEADER_TEMPLATE
         * @type String
         * @static
         */
        HEADER_TEMPLATE :
            '<div class="{console_hd_class}">'+
                '<h4 class="{console_title_class}">{str_title}</h4>'+
                '<button type="button" class="'+
                    '{console_button_class} {console_collapse_class}">{str_collapse}'+
                '</button>'+
            '</div>',

        /**
         * Markup template used to generate the DOM structure for the Console body
         * (where the messages are inserted) when it is rendered.  The template
         * includes only the {placeholder} &quot;console_bd_class&quot;, which is
         * constributed by Console.CHROME_CLASSES.
         *
         * @property Console.BODY_TEMPLATE
         * @type String
         * @static
         */
        BODY_TEMPLATE : '<div class="{console_bd_class}"></div>',

        /**
         * Markup template used to generate the DOM structure for the footer
         * section of the Console when it is rendered.  The template includes
         * many of the {placeholder}s from Console.CHROME_CLASSES as well as:
         *
         * <ul>
         *   <li>id_guid - generated unique id, relates the label and checkbox</li>
         *   <li>str_pause - pulled from attribute strings.pause</li>
         *   <li>str_clear - pulled from attribute strings.clear</li>
         * </ul>
         *
         * @property Console.FOOTER_TEMPLATE
         * @type String
         * @static
         */
        FOOTER_TEMPLATE :
            '<div class="{console_ft_class}">'+
                '<div class="{console_controls_class}">'+
                    '<label for="{id_guid}" class="{console_pause_label_class}">'+
                        '<input type="checkbox" class="{console_checkbox_class} '+
                            '{console_pause_class}" value="1" id="{id_guid}"> '+
                        '{str_pause}</label>' +
                    '<button type="button" class="'+
                        '{console_button_class} {console_clear_class}">{str_clear}'+
                    '</button>'+
                '</div>'+
            '</div>',

        /**
         * Default markup template used to create the DOM structure for Console
         * entries. The markup contains {placeholder}s for content and classes
         * that are replaced via Y.substitute.  The default template contains
         * the {placeholder}s identified in Console.ENTRY_CLASSES as well as the
         * following placeholders that will be populated by the log entry data:
         *
         * <ul>
         *   <li>cat_class</li>
         *   <li>src_class</li>
         *   <li>label</li>
         *   <li>totalTime</li>
         *   <li>elapsedTime</li>
         *   <li>localTime</li>
         *   <li>sourceAndDetail</li>
         *   <li>message</li>
         * </ul>
         *
         * @property Console.ENTRY_TEMPLATE
         * @type String
         * @static
         */
        ENTRY_TEMPLATE :
            '<div class="{entry_class} {cat_class} {src_class}">'+
                '<p class="{entry_meta_class}">'+
                    '<span class="{entry_src_class}">'+
                        '{sourceAndDetail}'+
                    '</span>'+
                    '<span class="{entry_cat_class}">'+
                        '{label}</span>'+
                    '<span class="{entry_time_class}">'+
                        ' {totalTime}ms (+{elapsedTime}) {localTime}'+
                    '</span>'+
                '</p>'+
                '<pre class="{entry_content_class}">{message}</pre>'+
            '</div>',

        /**
         * Static property used to define the default attribute configuration of
         * the Widget.
         *
         * @property Console.ATTRS
         * @Type Object
         * @static
         */
        ATTRS : {

            /**
             * Name of the custom event that will communicate log messages.
             *
             * @attribute logEvent
             * @type String
             * @default "yui:log"
             */
            logEvent : {
                value : 'yui:log',
                writeOnce : true,
                validator : isString
            },

            /**
             * Object that will emit the log events.  By default the YUI instance.
             * To have a single Console capture events from all YUI instances, set
             * this to the Y.Global object.
             *
             * @attribute logSource
             * @type EventTarget
             * @default Y
             */
            logSource : {
                value : Y,
                writeOnce : true,
                validator : function (v) {
                    return v && Y.Lang.isFunction(v.on);
                }
            },

            /**
             * Collection of strings used to label elements in the Console UI.
             * Default collection contains the following name:value pairs:
             *
             * <ul>
             *   <li>title : &quot;Log Console&quot;</li>
             *   <li>pause : &quot;Pause&quot;</li>
             *   <li>clear : &quot;Clear&quot;</li>
             *   <li>collapse : &quot;Collapse&quot;</li>
             *   <li>expand : &quot;Expand&quot;</li>
             * </ul>
             *
             * @attribute strings
             * @type Object
             */
            strings : {
                value : {
                    title : "Log Console",
                    pause : "Pause",
                    clear : "Clear",
                    collapse : "Collapse",
                    expand   : "Expand"
                }
            },

            /**
             * Boolean to pause the outputting of new messages to the console.
             * When paused, messages will accumulate in the buffer.
             *
             * @attribute paused
             * @type boolean
             * @default false
             */
            paused : {
                value : false,
                validator : L.isBoolean
            },

            /**
             * If a category is not specified in the Y.log(..) statement, this
             * category will be used. Categories &quot;info&quot;,
             * &quot;warn&quot;, and &quot;error&quot; are also called log level.
             *
             * @attribute defaultCategory
             * @type String
             * @default "info"
             */
            defaultCategory : {
                value : INFO,
                validator : isString
            },

            /**
             * If a source is not specified in the Y.log(..) statement, this
             * source will be used.
             *
             * @attribute defaultSource
             * @type String
             * @default "global"
             */
            defaultSource   : {
                value : 'global',
                validator : isString
            },

            /**
             * Markup template used to create the DOM structure for Console entries.
             *
             * @attribute entryTemplate
             * @type String
             * @default (see Console.ENTRY_TEMPLATE)
             */
            entryTemplate : {
                value : '',
                validator : isString
            },

            /**
             * Minimum entry log level to render into the Console.  The initial
             * logLevel value for all Console instances defaults from the
             * Y.config.logLevel YUI configuration, or Console.LOG_LEVEL_INFO if
             * that configuration is not set.
             *
             * Possible values are &quot;info&quot;, &quot;warn&quot;,
             * &quot;error&quot; (case insensitive), or their corresponding statics
             * Console.LOG_LEVEL_INFO and so on.
             *
             * @attribute logLevel
             * @type String
             * @default Y.config.logLevel or Console.LOG_LEVEL_INFO
             */
            logLevel : {
                value : Y.config.logLevel || INFO,
                setter : function (v) {
                    return this._setLogLevel(v);
                }
            },

            /**
             * Millisecond timeout between iterations of the print loop, moving
             * entries from the buffer to the UI.
             *
             * @attribute printTimeout
             * @type Number
             * @default 100
             */
            printTimeout : {
                value : 100,
                validator : isNumber
            },

            /**
             * Maximum number of entries printed in each iteration of the print
             * loop. This is used to prevent excessive logging locking the page UI.
             *
             * @attribute printLimit
             * @type Number
             * @default 50
             */
            printLimit : {
                value : 50,
                validator : isNumber
            },

            /**
             * Maximum number of Console entries allowed in the Console body at one
             * time.  This is used to keep acquired messages from exploding the
             * DOM tree and impacting page performance.
             *
             * @attribute consoleLimit
             * @type Number
             * @default 300
             */
            consoleLimit : {
                value : 300,
                validator : isNumber
            },

            /**
             * New entries should display at the top of the Console or the bottom?
             *
             * @attribute newestOnTop
             * @type Boolean
             * @default true
             */
            newestOnTop : {
                value : true
            },

            /**
             * When new entries are added to the Console UI, should they be
             * scrolled into view?
             *
             * @attribute scrollIntoView
             * @type Boolean
             * @default true
             */
            scrollIntoView : {
                value : true
            },

            /**
             * The baseline time for this Console instance, used to measure elapsed
             * time from the moment the console module is <code>use</code>d to the
             * moment each new entry is logged (not rendered).
             *
             * This value is reset by the instance method myConsole.reset().
             *
             * @attribute startTime
             * @type Date
             * @default The moment the console module is <code>use</code>d
             */
            startTime : {
                value : new Date()
            },

            /**
             * The precise time the last entry was logged.  Used to measure elapsed
             * time between log messages.
             *
             * @attribute lastTime
             * @type Date
             * @default The moment the console module is <code>use</code>d
             */
            lastTime : {
                value : new Date(),
                readOnly: true
            },

            /**
             * Controls the collapsed state of the Console
             *
             * @attribute collapsed
             * @type Boolean
             * @default false
             */
            collapsed : {
                value : false
            },

            /**
            * String with units, or number, representing the height of the Console,
            * inclusive of header and footer. If a number is provided, the default
            * unit, defined by Widget's DEF_UNIT, property is used.
            *
            * @attribute height
            * @default "300px"
            * @type {String | Number}
            */
            height: {
                value: "300px"
            },

            /**
            * String with units, or number, representing the width of the Console.
            * If a number is provided, the default unit, defined by Widget's
            * DEF_UNIT, property is used.
            *
            * @attribute width
            * @default "300px"
            * @type {String | Number}
            */
            width: {
                value: "300px"
            }
        }

    });

    Y.extend(Console,Y.Widget,{

        /**
         * Category to prefix all event subscriptions to allow for ease of detach
         * during destroy.
         *
         * @property _evtCat
         * @type string
         * @protected
         */
        _evtCat : null,

        /**
         * Reference to the Node instance containing the header contents.
         *
         * @property _head
         * @type Node
         * @default null
         * @protected
         */
        _head    : null,

        /**
         * Reference to the Node instance that will house the console messages.
         *
         * @property _body
         * @type Node
         * @default null
         * @protected
         */
        _body    : null,

        /**
         * Reference to the Node instance containing the footer contents.
         *
         * @property _foot
         * @type Node
         * @default null
         * @protected
         */
        _foot    : null,

        /**
         * Holds the object API returned from <code>Y.later</code> for the print
         * loop interval.
         *
         * @property _printLoop
         * @type Object
         * @default null
         * @protected
         */
        _printLoop : null,

        /**
         * Array of normalized message objects awaiting printing.
         *
         * @property buffer
         * @type Array
         * @default null
         * @protected
         */
        buffer   : null,

        /**
         * Wrapper for <code>Y.log</code>.
         *
         * @method log
         * @param arg* {MIXED} (all arguments passed through to <code>Y.log</code>)
         */
        log : function () {
            return Y.log.apply(Y,arguments);
        },

        /**
         * Clear the console of messages and flush the buffer of pending messages.
         *
         * @method clearConsole
         * @chainable
         */
        clearConsole : function () {
            // TODO: clear event listeners from console contents
            this._body.set(INNER_HTML,'');

            this._cancelPrintLoop();

            this.buffer = [];

            return this;
        },

        /**
         * Clears the console and resets internal timers.
         *
         * @method reset
         * @chainable
         */
        reset : function () {
            this.fire(RESET);

            return this;
        },

        /**
         * Collapses the body and footer.
         *
         * @method collapse
         */
        collapse : function () {
            this.set(COLLAPSED, true);
        },

        /**
         * Expands the body and footer if collapsed.
         *
         * @method expand
         */
        expand : function () {
            this.set(COLLAPSED, false);
        },

        /**
         * Outputs buffered messages to the console UI.  This is typically called
         * from a scheduled interval until the buffer is empty (referred to as the
         * print loop).  The number of buffered messages output to the Console is
         * limited to the number provided as an argument.  If no limit is passed,
         * all buffered messages are rendered.
         *
         * @method printBuffer
         * @param limit {Number} (optional) max number of buffered entries to write
         * @chainable
         */
        printBuffer: function (limit) {
            var messages    = this.buffer,
                debug       = Y.config.debug,
                entries     = [],
                consoleLimit= this.get('consoleLimit'),
                newestOnTop = this.get('newestOnTop'),
                anchor      = newestOnTop ? this._body.get('firstChild') : null,
                i;

            if (messages.length > consoleLimit) {
                messages.splice(0, messages.length - consoleLimit);
            }

            limit = Math.min(messages.length, (limit || messages.length));

            // turn off logging system
            Y.config.debug = false;

            if (!this.get(PAUSED) && this.get('rendered')) {

                for (i = 0; i < limit && messages.length; ++i) {
                    entries[i] = this._createEntryHTML(messages.shift());
                }

                if (!messages.length) {
                    this._cancelPrintLoop();
                }

                if (newestOnTop) {
                    entries.reverse();
                }

                this._body.insertBefore(create(entries.join('')), anchor);

                if (this.get('scrollIntoView')) {
                    this.scrollToLatest();
                }

                this._trimOldEntries();

            }

            // restore logging system
            Y.config.debug = debug;

            return this;
        },

        /**
         * Constructor code.  Set up the buffer and entry template, publish
         * internal events, and subscribe to the configured logEvent.
         *
         * @method initializer
         * @protected
         */
        initializer : function () {
            this._evtCat = Y.stamp(this) + '|';

            this.buffer = [];

            if (!this.get(ENTRY_TEMPLATE)) {
                this.set(ENTRY_TEMPLATE,Console.ENTRY_TEMPLATE);
            }

            this.get('logSource').on(this._evtCat +
                this.get('logEvent'),Y.bind("_onLogEvent",this));

            /**
             * Transfers a received message to the print loop buffer.  Default
             * behavior defined in _defEntryFn.
             *
             * @event entry
             * @param event {Event.Facade} An Event Facade object with the following attribute specific properties added:
             *  <dl>
             *      <dt>message</dt>
             *          <dd>The message data normalized into an object literal (see _normalizeMessage)</dd>
             *  </dl>
             * @preventable _defEntryFn
             */
            this.publish(ENTRY, { defaultFn: this._defEntryFn });

            /**
             * Triggers the reset behavior via the default logic in _defResetFn.
             *
             * @event reset
             * @param event {Event.Facade} Event Facade object
             * @preventable _defResetFn
             */
            this.publish(RESET, { defaultFn: this._defResetFn });

            this.after('rendered', this._schedulePrint);
        },

        /**
         * Tears down the instance, flushing event subscriptions and purging the UI.
         *
         * @method destructor
         * @protected
         */
        destructor : function () {
            var bb = this.get('boundingBox');

            this._cancelPrintLoop();

            this.get('logSource').detach(this._evtCat + '*');

            Y.Event.purgeElement(bb, true);

            bb.set('innerHTML','');
        },

        /**
         * Generate the Console UI.
         *
         * @method renderUI
         * @protected
         */
        renderUI : function () {
            this._initHead();
            this._initBody();
            this._initFoot();
        },

        /**
         * Sync the UI state to the current attribute state.
         *
         * @method syncUI
         */
        syncUI : function () {
            this._uiUpdatePaused(this.get(PAUSED));
            this._uiUpdateCollapsed(this.get(COLLAPSED));
            this._uiSetHeight(this.get(HEIGHT));
        },

        /**
         * Set up event listeners to wire up the UI to the internal state.
         *
         * @method bindUI
         * @protected
         */
        bindUI : function () {
            this.get(CONTENT_BOX).query('button.'+C_COLLAPSE).
                on(CLICK,this._onCollapseClick,this);

            this.get(CONTENT_BOX).query('input[type=checkbox].'+C_PAUSE).
                on(CLICK,this._onPauseClick,this);

            this.get(CONTENT_BOX).query('button.'+C_CLEAR).
                on(CLICK,this._onClearClick,this);

            // Attribute changes
            this.after(this._evtCat + 'stringsChange',
                this._afterStringsChange);
            this.after(this._evtCat + 'pausedChange',
                this._afterPausedChange);
            this.after(this._evtCat + 'consoleLimitChange',
                this._afterConsoleLimitChange);
            this.after(this._evtCat + 'collapsedChange',
                this._afterCollapsedChange);
        },

        /**
         * Create the DOM structure for the header elements.
         *
         * @method _initHead
         * @protected
         */
        _initHead : function () {
            var cb   = this.get(CONTENT_BOX),
                info = merge(Console.CHROME_CLASSES, {
                            str_collapse : this.get('strings.collapse'),
                            str_title : this.get('strings.title')
                        });

            this._head = create(substitute(Console.HEADER_TEMPLATE,info));

            cb.insertBefore(this._head,cb.get('firstChild'));
        },

        /**
         * Create the DOM structure for the console body&#8212;where messages are
         * rendered.
         *
         * @method _initBody
         * @protected
         */
        _initBody : function () {
            this._body = create(substitute(
                                Console.BODY_TEMPLATE,
                                Console.CHROME_CLASSES));

            this.get(CONTENT_BOX).appendChild(this._body);
        },

        /**
         * Create the DOM structure for the footer elements.
         *
         * @method _initFoot
         * @protected
         */
        _initFoot : function () {
            var info = merge(Console.CHROME_CLASSES, {
                    id_guid   : Y.guid(),
                    str_pause : this.get('strings.pause'),
                    str_clear : this.get('strings.clear')
                });

            this._foot = create(substitute(Console.FOOTER_TEMPLATE,info));

            this.get(CONTENT_BOX).appendChild(this._foot);
        },

        /**
         * Determine if incoming log messages are within the configured logLevel
         * to be buffered for printing.
         *
         * @method _isInLogLevel
         * @protected
         */
        _isInLogLevel : function (e) {
            var cat = e.cat, lvl = this.get('logLevel');

            if (lvl !== INFO) {
                cat = cat || INFO;

                if (isString(cat)) {
                    cat = cat.toLowerCase();
                }

                if ((cat === WARN && lvl === ERROR) ||
                    (cat === INFO && lvl !== INFO)) {
                    return false;
                }
            }

            return true;
        },

        /**
         * Create a log entry message from the inputs including the following keys:
         * <ul>
         *     <li>time - this moment</li>
         *     <li>message - leg message</li>
         *     <li>category - logLevel or custom category for the message</li>
         *     <li>source - when provided, the widget or util calling Y.log</li>
         *     <li>sourceAndDetail - same as source but can include instance info</li>
         *     <li>label - logLevel/category label for the entry</li>
         *     <li>localTime - readable version of time</li>
         *     <li>elapsedTime - ms since last entry</li>
         *     <li>totalTime - ms since Console was instantiated or reset</li>
         * </ul>
         *
         * @method _normalizeMessage
         * @param e {Event} custom event containing the log message
         * @return Object the message object
         * @protected
         */
        _normalizeMessage : function (e) {

            var msg = e.msg,
                cat = e.cat,
                src = e.src,

                m = {
                    time            : new Date(),
                    message         : msg,
                    category        : cat || this.get('defaultCategory'),
                    sourceAndDetail : src || this.get('defaultSource'),
                    source          : null,
                    label           : null,
                    localTime       : null,
                    elapsedTime     : null,
                    totalTime       : null
                };

            // Extract m.source "Foo" from m.sourceAndDetail "Foo bar baz"
            m.source          = RE_INLINE_SOURCE.test(m.sourceAndDetail) ?
                                    RegExp.$1 : m.sourceAndDetail;
            m.label           = m.category;
            m.localTime       = m.time.toLocaleTimeString ?
                                m.time.toLocaleTimeString() : (m.time + '');
            m.elapsedTime     = m.time - this.get(LAST_TIME);
            m.totalTime       = m.time - this.get(START_TIME);

            this._set(LAST_TIME,m.time);

            return m;
        },

        /**
         * Sets an interval for buffered messages to be output to the console.
         *
         * @method _schedulePrint
         * @protected
         */
        _schedulePrint : function () {
            if (!this._printLoop && !this.get(PAUSED) && this.get('rendered')) {
                this._printLoop = Y.later(
                                    this.get('printTimeout'),
                                    this, this.printBuffer,
                                    this.get('printLimit'), true);
            }
        },

        /**
         * Translates message meta into the markup for a console entry.
         *
         * @method _createEntryHTML
         * @param m {Object} object literal containing normalized message metadata
         * @return String
         * @protected
         */
        _createEntryHTML : function (m) {
            m = merge(
                    this._htmlEscapeMessage(m),
                    Console.ENTRY_CLASSES,
                    {
                        cat_class : this.getClassName(ENTRY,m.category),
                        src_class : this.getClassName(ENTRY,m.source)
                    });

            return this.get('entryTemplate').replace(/\{(\w+)\}/g,
                function (_,token) {
                    return token in m ? m[token] : '';
                });
        },

        /**
         * Scrolls to the most recent entry
         *
         * @method scrollToLatest
         * @chainable
         */
        scrollToLatest : function () {
            var scrollTop = this.get('newestOnTop') ?
                                0 :
                                this._body.get('scrollHeight');

            this._body.set('scrollTop', scrollTop);
        },

        /**
         * Performs HTML escaping on strings in the message object.
         *
         * @method _htmlEscapeMessage
         * @param m {Object} the normalized message object
         * @return Object a clone of the message object with proper escapement
         * @protected
         */
        _htmlEscapeMessage : function (m) {
            m = Y.clone(m);
            m.message         = this._encodeHTML(m.message);
            m.label           = this._encodeHTML(m.label);
            m.source          = this._encodeHTML(m.source);
            m.sourceAndDetail = this._encodeHTML(m.sourceAndDetail);
            m.category        = this._encodeHTML(m.category);

            return m;
        },

        /**
         * Removes the oldest message entries from the UI to maintain the limit
         * specified in the consoleLimit configuration.
         *
         * @method _trimOldEntries
         * @protected
         */
        _trimOldEntries : function () {
            // Turn off the logging system for the duration of this operation
            // to prevent an infinite loop
            Y.config.debug = false;

            var bd = this._body,
                limit = this.get('consoleLimit'),
                debug = Y.config.debug,
                entries,e,i,l;

            if (bd) {
                entries = bd.queryAll(DOT+C_ENTRY);
                l = entries.size() - limit;

                if (l > 0) {
                    if (this.get('newestOnTop')) {
                        i = limit;
                        l = entries.size();
                    } else {
                        i = 0;
                    }

                    this._body.setStyle('display','none');

                    for (;i < l; ++i) {
                        e = entries.item(i);
                        if (e) {
                            e.get('parentNode').removeChild(e);
                        }
                    }

                    this._body.setStyle('display','');
                }

            }

            Y.config.debug = debug;
        },

        /**
         * Returns the input string with ampersands (&amp;), &lt, and &gt; encoded
         * as HTML entities.
         *
         * @method _encodeHTML
         * @param s {String} the raw string
         * @return String the encoded string
         * @protected
         */
        _encodeHTML : function (s) {
            return isString(s) ?
                s.replace(RE_AMP,ESC_AMP).
                  replace(RE_LT, ESC_LT).
                  replace(RE_GT, ESC_GT) :
                s;
        },

        /**
         * Clears the timeout for printing buffered messages.
         *
         * @method _cancelPrintLoop
         * @protected
         */
        _cancelPrintLoop : function () {
            if (this._printLoop) {
                this._printLoop.cancel();
                this._printLoop = null;
            }
        },

        /**
         * Event handler for clicking on the Pause checkbox to update the paused
         * attribute.
         *
         * @method _onPauseClick
         * @param e {Event} DOM event facade for the click event
         * @protected
         */
        _onPauseClick : function (e) {
            this.set(PAUSED,e.target.get(CHECKED));
        },

        /**
         * Event handler for clicking on the Clear button.  Pass-through to
         * <code>this.clearConsole()</code>.
         *
         * @method _onClearClick
         * @param e {Event} DOM event facade for the click event
         * @protected
         */
        _onClearClick : function (e) {
            this.clearConsole();
        },

        /**
         * Event handler for clicking on the Collapse/Expand button. Sets the
         * &quot;collapsed&quot; attribute accordingly.
         *
         * @method _onCollapseClick
         * @param e {Event} DOM event facade for the click event
         * @protected
         */
        _onCollapseClick : function (e) {
            this.set(COLLAPSED, !this.get(COLLAPSED));
        },

        /**
         * Setter method for logLevel attribute.  Acceptable values are
         * &quot;error&quot, &quot;warn&quot, and &quot;info&quot (case
         * insensitive).  Other values are treated as &quot;info&quot;.
         *
         * @method _setLogLevel
         * @param v {String} the desired log level
         * @return String One of Console.LOG_LEVEL_INFO, _WARN, or _ERROR
         * @protected
         */
        _setLogLevel : function (v) {
            if (isString(v)) {
                v = v.toLowerCase();
            }

            return (v === WARN || v === ERROR) ? v : INFO;
        },

        /**
         * Set the height of the Console container.  Set the body height to the difference between the configured height and the calculated heights of the header and footer.
         * Overrides Widget.prototype._uiSetHeight.
         *
         * @method _uiSetHeight
         * @param v {String|Number} the new height
         * @protected
         */
        _uiSetHeight : function (v) {
            Console.superclass._uiSetHeight.apply(this,arguments);

            if (this._head && this._foot) {
                var h = this.get('boundingBox').get('offsetHeight') -
                        this._head.get('offsetHeight') -
                        this._foot.get('offsetHeight');

                this._body.setStyle(HEIGHT,h+'px');
            }
        },

        /**
         * Updates the UI if changes are made to any of the strings in the strings
         * attribute.
         *
         * @method _afterStringsChange
         * @param e {Event} Custom event for the attribute change
         * @protected
         */
        _afterStringsChange : function (e) {
            var prop   = e.subAttrName ? e.subAttrName.split(DOT)[1] : null,
                cb     = this.get(CONTENT_BOX),
                before = e.prevVal,
                after  = e.newVal,
                el;

            if ((!prop || prop === TITLE) && before.title !== after.title) {
                el = cb.query(DOT+C_CONSOLE_TITLE);
                if (el) {
                    el.set(INNER_HTML,after.title);
                }
            }

            if ((!prop || prop === PAUSE) && before.pause !== after.pause) {
                el = cb.query(DOT+C_PAUSE_LABEL);
                if (el) {
                    el.set(INNER_HTML,after.pause);
                }
            }

            if ((!prop || prop === CLEAR) && before.clear !== after.clear) {
                el = cb.query(DOT+C_CLEAR);
                if (el) {
                    el.set('value',after.clear);
                }
            }
        },

        /**
         * Updates the UI and schedules or cancels the print loop.
         *
         * @method _afterPausedChange
         * @param e {Event} Custom event for the attribute change
         * @protected
         */
        _afterPausedChange : function (e) {
            var paused = e.newVal;

            if (e.src !== Y.Widget.SRC_UI) {
                this._uiUpdatePaused(paused);
            }

            if (!paused) {
                this._schedulePrint();
            } else if (this._printLoop) {
                this._cancelPrintLoop();
            }
        },

        /**
         * Checks or unchecks the paused checkbox
         *
         * @method _uiUpdatePaused
         * @param on {Boolean} the new checked state
         * @protected
         */
        _uiUpdatePaused : function (on) {
            var node = this._foot.queryAll('input[type=checkbox].'+C_PAUSE);

            if (node) {
                node.set(CHECKED,on);
            }
        },

        /**
         * Calls this._trimOldEntries() in response to changes in the configured
         * consoleLimit attribute.
         *
         * @method _afterConsoleLimitChange
         * @param e {Event} Custom event for the attribute change
         * @protected
         */
        _afterConsoleLimitChange : function () {
            this._trimOldEntries();
        },

        /**
         * Updates the className of the contentBox, which should trigger CSS to
         * hide or show the body and footer sections depending on the new value.
         *
         * @method _afterCollapsedChange
         * @param e {Event} Custom event for the attribute change
         * @protected
         */
        _afterCollapsedChange : function (e) {
            this._uiUpdateCollapsed(e.newVal);
        },

        /**
         * Updates the UI to reflect the new Collapsed state
         *
         * @method _uiUpdateCollapsed
         * @param v {Boolean} true for collapsed, false for expanded
         * @protected
         */
        _uiUpdateCollapsed : function (v) {
            var cb     = this.get(CONTENT_BOX),
                button = cb.queryAll('button.'+C_COLLAPSE),
                method = v ? 'addClass' : 'removeClass',
                str    = this.get('strings.'+(v ? 'expand' : 'collapse'));

            cb[method](C_COLLAPSED);

            if (button) {
                button.set('innerHTML',str);
            }

            if (!v) {
                this._uiSetHeight(this.get(HEIGHT));
            }
        },

        /**
         * Makes adjustments to the UI if needed when the Console is hidden or shown
         *
         * @method _afterVisibleChange
         * @param e {Event} the visibleChange event
         * @protected
         */
        _afterVisibleChange : function (e) {
            Console.superclass._afterVisibleChange.apply(this,arguments);

            this._uiUpdateFromHideShow(e.newVal);
        },

        /**
         * Recalculates dimensions and updates appropriately when shown
         *
         * @method _uiUpdateFromHideShow
         * @param v {Boolean} true for visible, false for hidden
         * @protected
         */
        _uiUpdateFromHideShow : function (v) {
            if (v) {
                this._uiSetHeight(this.get(HEIGHT));
            }
        },

        /**
         * Responds to log events by normalizing qualifying messages and passing
         * them along through the entry event for buffering etc.
         *
         * @method _onLogEvent
         * @param msg {String} the log message
         * @param cat {String} OPTIONAL the category or logLevel of the message
         * @param src {String} OPTIONAL the source of the message (e.g. widget name)
         * @protected
         */
        _onLogEvent : function (e) {

            if (!this.get(DISABLED) && this._isInLogLevel(e)) {

                var debug = Y.config.debug;

                /* TODO: needed? */
                Y.config.debug = false;

                this.fire(ENTRY, {
                    message : this._normalizeMessage(e)
                });

                Y.config.debug = debug;
            }
        },

        /**
         * Clears the console, resets the startTime attribute, enables and
         * unpauses the widget.
         *
         * @method _defResetFn
         * @protected
         */
        _defResetFn : function () {
            this.clearConsole();
            this.set(START_TIME,new Date());
            this.set(DISABLED,false);
            this.set(PAUSED,false);
        },

        /**
         * Buffers incoming message objects and schedules the printing.
         *
         * @method _defEntryFn
         * @param e {Event} The Custom event carrying the message in its payload
         * @protected
         */
        _defEntryFn : function (e) {
            if (e.message) {
                this.buffer.push(e.message);
                this._schedulePrint();
            }
        }

    });

    Y.Console = Console;

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