/**
* The Logger widget provides a simple way to read or write log messages in
* JavaScript code. Integration with the YUI Library's debug builds allow
* implementers to access under-the-hood events, errors, and debugging messages.
* Output may be read through a LogReader console and/or output to a browser
* console.
*
* @module logger
* @requires yahoo, event, dom
* @optional dragdrop
* @namespace YAHOO.widget
* @title Logger Widget
*/
/****************************************************************************/
/****************************************************************************/
/****************************************************************************/
// Define once
if(!YAHOO.widget.Logger) {
/**
* The singleton Logger class provides core log management functionality. Saves
* logs written through the global YAHOO.log function or written by a LogWriter
* instance. Provides access to logs for reading by a LogReader instance or
* native browser console such as the Firebug extension to Firefox or Safari's
* JavaScript console through integration with the console.log() method.
*
* @class Logger
* @static
*/
YAHOO.widget.Logger = {
// Initialize properties
loggerEnabled: true,
_browserConsoleEnabled: false,
categories: ["info","warn","error","time","window"],
sources: ["global"],
_stack: [], // holds all log msgs
maxStackEntries: 2500,
_startTime: new Date().getTime(), // static start timestamp
_lastTime: null, // timestamp of last logged message
_windowErrorsHandled: false,
_origOnWindowError: null
};
/////////////////////////////////////////////////////////////////////////////
//
// Public properties
//
/////////////////////////////////////////////////////////////////////////////
/**
* True if Logger is enabled, false otherwise.
*
* @property loggerEnabled
* @type Boolean
* @static
* @default true
*/
/**
* Array of categories.
*
* @property categories
* @type String[]
* @static
* @default ["info","warn","error","time","window"]
*/
/**
* Array of sources.
*
* @property sources
* @type String[]
* @static
* @default ["global"]
*/
/**
* Upper limit on size of internal stack.
*
* @property maxStackEntries
* @type Number
* @static
* @default 2500
*/
/////////////////////////////////////////////////////////////////////////////
//
// Private properties
//
/////////////////////////////////////////////////////////////////////////////
/**
* Internal property to track whether output to browser console is enabled.
*
* @property _browserConsoleEnabled
* @type Boolean
* @static
* @default false
* @private
*/
/**
* Array to hold all log messages.
*
* @property _stack
* @type Array
* @static
* @private
*/
/**
* Static timestamp of Logger initialization.
*
* @property _startTime
* @type Date
* @static
* @private
*/
/**
* Timestamp of last logged message.
*
* @property _lastTime
* @type Date
* @static
* @private
*/
/////////////////////////////////////////////////////////////////////////////
//
// Public methods
//
/////////////////////////////////////////////////////////////////////////////
/**
* Saves a log message to the stack and fires newLogEvent. If the log message is
* assigned to an unknown category, creates a new category. If the log message is
* from an unknown source, creates a new source. If browser console is enabled,
* outputs the log message to browser console.
*
* @method log
* @param sMsg {String} The log message.
* @param sCategory {String} Category of log message, or null.
* @param sSource {String} Source of LogWriter, or null if global.
*/
YAHOO.widget.Logger.log = function(sMsg, sCategory, sSource) {
if(this.loggerEnabled) {
if(!sCategory) {
sCategory = "info"; // default category
}
else {
sCategory = sCategory.toLocaleLowerCase();
if(this._isNewCategory(sCategory)) {
this._createNewCategory(sCategory);
}
}
var sClass = "global"; // default source
var sDetail = null;
if(sSource) {
var spaceIndex = sSource.indexOf(" ");
if(spaceIndex > 0) {
// Substring until first space
sClass = sSource.substring(0,spaceIndex);
// The rest of the source
sDetail = sSource.substring(spaceIndex,sSource.length);
}
else {
sClass = sSource;
}
if(this._isNewSource(sClass)) {
this._createNewSource(sClass);
}
}
var timestamp = new Date();
var logEntry = new YAHOO.widget.LogMsg({
msg: sMsg,
time: timestamp,
category: sCategory,
source: sClass,
sourceDetail: sDetail
});
var stack = this._stack;
var maxStackEntries = this.maxStackEntries;
if(maxStackEntries && !isNaN(maxStackEntries) &&
(stack.length >= maxStackEntries)) {
stack.shift();
}
stack.push(logEntry);
this.newLogEvent.fire(logEntry);
if(this._browserConsoleEnabled) {
this._printToBrowserConsole(logEntry);
}
return true;
}
else {
return false;
}
};
/**
* Resets internal stack and startTime, enables Logger, and fires logResetEvent.
*
* @method reset
*/
YAHOO.widget.Logger.reset = function() {
this._stack = [];
this._startTime = new Date().getTime();
this.loggerEnabled = true;
this.log("Logger reset");
this.logResetEvent.fire();
};
/**
* Public accessor to internal stack of log message objects.
*
* @method getStack
* @return {Object[]} Array of log message objects.
*/
YAHOO.widget.Logger.getStack = function() {
return this._stack;
};
/**
* Public accessor to internal start time.
*
* @method getStartTime
* @return {Date} Internal date of when Logger singleton was initialized.
*/
YAHOO.widget.Logger.getStartTime = function() {
return this._startTime;
};
/**
* Disables output to the browser's global console.log() function, which is used
* by the Firebug extension to Firefox as well as Safari.
*
* @method disableBrowserConsole
*/
YAHOO.widget.Logger.disableBrowserConsole = function() {
YAHOO.log("Logger output to the function console.log() has been disabled.");
this._browserConsoleEnabled = false;
};
/**
* Enables output to the browser's global console.log() function, which is used
* by the Firebug extension to Firefox as well as Safari.
*
* @method enableBrowserConsole
*/
YAHOO.widget.Logger.enableBrowserConsole = function() {
this._browserConsoleEnabled = true;
YAHOO.log("Logger output to the function console.log() has been enabled.");
};
/**
* Surpresses native JavaScript errors and outputs to console. By default,
* Logger does not handle JavaScript window error events.
* NB: Not all browsers support the window.onerror event.
*
* @method handleWindowErrors
*/
YAHOO.widget.Logger.handleWindowErrors = function() {
if(!YAHOO.widget.Logger._windowErrorsHandled) {
// Save any previously defined handler to call
if(window.error) {
YAHOO.widget.Logger._origOnWindowError = window.onerror;
}
window.onerror = YAHOO.widget.Logger._onWindowError;
YAHOO.widget.Logger._windowErrorsHandled = true;
YAHOO.log("Logger handling of window.onerror has been enabled.");
}
else {
YAHOO.log("Logger handling of window.onerror had already been enabled.");
}
};
/**
* Unsurpresses native JavaScript errors. By default,
* Logger does not handle JavaScript window error events.
* NB: Not all browsers support the window.onerror event.
*
* @method unhandleWindowErrors
*/
YAHOO.widget.Logger.unhandleWindowErrors = function() {
if(YAHOO.widget.Logger._windowErrorsHandled) {
// Revert to any previously defined handler to call
if(YAHOO.widget.Logger._origOnWindowError) {
window.onerror = YAHOO.widget.Logger._origOnWindowError;
YAHOO.widget.Logger._origOnWindowError = null;
}
else {
window.onerror = null;
}
YAHOO.widget.Logger._windowErrorsHandled = false;
YAHOO.log("Logger handling of window.onerror has been disabled.");
}
else {
YAHOO.log("Logger handling of window.onerror had already been disabled.");
}
};
/////////////////////////////////////////////////////////////////////////////
//
// Public events
//
/////////////////////////////////////////////////////////////////////////////
/**
* Fired when a new category has been created.
*
* @event categoryCreateEvent
* @param sCategory {String} Category name.
*/
YAHOO.widget.Logger.categoryCreateEvent =
new YAHOO.util.CustomEvent("categoryCreate", this, true);
/**
* Fired when a new source has been named.
*
* @event sourceCreateEvent
* @param sSource {String} Source name.
*/
YAHOO.widget.Logger.sourceCreateEvent =
new YAHOO.util.CustomEvent("sourceCreate", this, true);
/**
* Fired when a new log message has been created.
*
* @event newLogEvent
* @param sMsg {String} Log message.
*/
YAHOO.widget.Logger.newLogEvent = new YAHOO.util.CustomEvent("newLog", this, true);
/**
* Fired when the Logger has been reset has been created.
*
* @event logResetEvent
*/
YAHOO.widget.Logger.logResetEvent = new YAHOO.util.CustomEvent("logReset", this, true);
/////////////////////////////////////////////////////////////////////////////
//
// Private methods
//
/////////////////////////////////////////////////////////////////////////////
/**
* Creates a new category of log messages and fires categoryCreateEvent.
*
* @method _createNewCategory
* @param sCategory {String} Category name.
* @private
*/
YAHOO.widget.Logger._createNewCategory = function(sCategory) {
this.categories.push(sCategory);
this.categoryCreateEvent.fire(sCategory);
};
/**
* Checks to see if a category has already been created.
*
* @method _isNewCategory
* @param sCategory {String} Category name.
* @return {Boolean} Returns true if category is unknown, else returns false.
* @private
*/
YAHOO.widget.Logger._isNewCategory = function(sCategory) {
for(var i=0; i < this.categories.length; i++) {
if(sCategory == this.categories[i]) {
return false;
}
}
return true;
};
/**
* Creates a new source of log messages and fires sourceCreateEvent.
*
* @method _createNewSource
* @param sSource {String} Source name.
* @private
*/
YAHOO.widget.Logger._createNewSource = function(sSource) {
this.sources.push(sSource);
this.sourceCreateEvent.fire(sSource);
};
/**
* Checks to see if a source already exists.
*
* @method _isNewSource
* @param sSource {String} Source name.
* @return {Boolean} Returns true if source is unknown, else returns false.
* @private
*/
YAHOO.widget.Logger._isNewSource = function(sSource) {
if(sSource) {
for(var i=0; i < this.sources.length; i++) {
if(sSource == this.sources[i]) {
return false;
}
}
return true;
}
};
/**
* Outputs a log message to global console.log() function.
*
* @method _printToBrowserConsole
* @param oEntry {Object} Log entry object.
* @private
*/
YAHOO.widget.Logger._printToBrowserConsole = function(oEntry) {
if(window.console && console.log) {
var category = oEntry.category;
var label = oEntry.category.substring(0,4).toUpperCase();
var time = oEntry.time;
var localTime;
if (time.toLocaleTimeString) {
localTime = time.toLocaleTimeString();
}
else {
localTime = time.toString();
}
var msecs = time.getTime();
var elapsedTime = (YAHOO.widget.Logger._lastTime) ?
(msecs - YAHOO.widget.Logger._lastTime) : 0;
YAHOO.widget.Logger._lastTime = msecs;
var output =
localTime + " (" +
elapsedTime + "ms): " +
oEntry.source + ": " +
oEntry.msg;
console.log(output);
}
};
/////////////////////////////////////////////////////////////////////////////
//
// Private event handlers
//
/////////////////////////////////////////////////////////////////////////////
/**
* Handles logging of messages due to window error events.
*
* @method _onWindowError
* @param sMsg {String} The error message.
* @param sUrl {String} URL of the error.
* @param sLine {String} Line number of the error.
* @private
*/
YAHOO.widget.Logger._onWindowError = function(sMsg,sUrl,sLine) {
// Logger is not in scope of this event handler
try {
YAHOO.widget.Logger.log(sMsg+' ('+sUrl+', line '+sLine+')', "window");
if(YAHOO.widget.Logger._origOnWindowError) {
YAHOO.widget.Logger._origOnWindowError();
}
}
catch(e) {
return false;
}
};
/////////////////////////////////////////////////////////////////////////////
//
// First log
//
/////////////////////////////////////////////////////////////////////////////
YAHOO.widget.Logger.log("Logger initialized");
}