js日志组件封装

js日志组件~~

 1         function Logger(level) {
            if (!(this instanceof Logger)) {
                return new Logger();
            }
            var ERROR = 1;
            var INFO = 2;
            var DEBUG = 3;

            var logLevel = null;

            var levels = {
                "debug": 3,
                "info": 2,
                "error": 1,
                "none": 0,
            }

            if (level === undefined) {
                logLevel = ERROR;
            } else {
                logLevel = level;
            }

            this.getLevelName = function (level) {

                for (var name in levels) {
                    if (levels[name] == level) {
                        return name;
                    }
                }
            }

            this.setLevel = function (newLevel) {

                logLevel = newLevel;
                console.log("setting log level to: " + this.getLevelName(newLevel));
            }

            var processMessage = function (msg, level) {
                if (level <= logLevel) {
                    console.log(msg);
                }
            }

            this.error = function (msg) {
                processMessage(msg, ERROR);
            };
            this.info = function (msg) {
                processMessage(msg, INFO);
            };
            this.debug = function (msg) {
                processMessage(msg, DEBUG);
            };

            var that = this;
        }
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        var logger = Logger();
        logger.error("haha");