lib/modules/util/Logger.js

/*
 *Licensed to the Apache Software Foundation (ASF) under one
 *or more contributor license agreements.  See the NOTICE file
 *distributed with this work for additional information
 *regarding copyright ownership.  The ASF licenses this file
 *to you under the Apache License, Version 2.0 (the
 *"License"); you may not use this file except in compliance
 *with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0

 *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.
 *
 *  @author ryan bridges (rbridges@apigee.com)
 */

//Logger
(function() {
    var name = 'Logger', global = this, overwrittenName = global[name], exports;
    /* logging */
    function Logger(name) {
        this.logEnabled = true;
        this.init(name, true);
    }
    Logger.METHODS=[
        "log", "error", "warn", "info", "debug", "assert", "clear", "count",
        "dir", "dirxml", "exception", "group", "groupCollapsed", "groupEnd",
        "profile", "profileEnd", "table", "time", "timeEnd", "trace"
    ];
    Logger.prototype.init=function(name, logEnabled){
        this.name=name||"UNKNOWN";
        this.logEnabled=logEnabled||true;
        var addMethod=function(method){this[method]=this.createLogMethod(method);}.bind(this);
        Logger.METHODS.forEach(addMethod);
    };
    Logger.prototype.createLogMethod=function(method){
        return Logger.prototype.log.bind(this, method);
    };
    Logger.prototype.prefix=function(method, args){
        var prepend='['+method.toUpperCase()+']['+name+"]:\t";
        if(['log', 'error', 'warn', 'info'].indexOf(method)!==-1){
            if("string"===typeof args[0]){
                args[0]=prepend+args[0];
            }else{
                args.unshift(prepend);
            }
        }
        return args;
    };
    Logger.prototype.log=function(){
        var args=[].slice.call(arguments);
        method=args.shift();
        if(Logger.METHODS.indexOf(method)===-1){
            method="log";
        }
        if(!(this.logEnabled && console && console[method]))return;
        args=this.prefix(method, args);
        console[method].apply(console, args);
    };
    Logger.prototype.setLogEnabled=function(logEnabled){
        this.logEnabled=logEnabled||true;
    };

    Logger.mixin	= function(destObject){
        destObject.__logger=new Logger(destObject.name||"UNKNOWN");
        var addMethod=function(method){
            if(method in destObject.prototype){
                console.warn("overwriting '"+method+"' on '"+destObject.name+"'.");
                console.warn("the previous version can be found at '_"+method+"' on '"+destObject.name+"'.");
                destObject.prototype['_'+method]=destObject.prototype[method];
            }
            destObject.prototype[method]=destObject.__logger.createLogMethod(method);
        };
        Logger.METHODS.forEach(addMethod);
    };
    global[name] =  Logger;
    global[name].noConflict = function() {
        if(overwrittenName){
            global[name] = overwrittenName;
        }
        return Logger;
    };
    return global[name];
}());