tanaka9230/logger-module-experiment.html

## logger-module-experiment.html
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta http-equiv="Pragma" content="no-cache">
<meta http-equiv="Cache-Control" content="no-cache">
<meta http-equiv="Expires" content="0">
<title>Logger Module Experiment</title>
</head>
<body>
<h1>Logger Module Experiment</h1>
<p>
See the output on the web console.
</p>
<!-- SCRIPTS -->
<script src="http://code.jquery.com/jquery-1.11.3.min.js"></script>
<script src="http://underscorejs.org/underscore-min.js"></script>
<script src="js/logger.js"></script>
<script>
Logger.log_level = Logger.LOG_LEVEL.DEBUG;
Logger.alert = true;
Logger.debug_dump("a string", "hoge");
Logger.debug_dump("an integer", 123);
Logger.debug_dump("a boolean", true);
Logger.debug_dump("an object", {x:1,y:"foo",z:{a:2,b:false}});
Logger.debug_dump("an object", new Date());
Logger.debug_trace("run through here");
Logger.debug_begins("my procedure");
Logger.debug_completed("my procedure");
Logger.debug_succeeded("my procedure");
Logger.debug_failed("my procedure");
try {
    xxxxx;
} catch (exp) {
    Logger.error_abend(exp);
}
</script>
<!-- /SCRIPTS -->
</body>
</html>

## logger.js
/*
 * LOGGER
 */
; (function(module_def) {
    var MODULE_NAME = "Logger";
    try {
        console.log(">> loading '" + MODULE_NAME + "' begins...");
        var export_target = this;
        export_target[MODULE_NAME] = module_def();
        // TODO more precise exporting procedure
        console.log("<< loading '" + MODULE_NAME + "' succeeded. (^_^)");
    } catch (exp) {
        console.error("<< loading '" + MODULE_NAME + "' FAILED! (T_T) : " + exp);
        console.dir(exp);
    }
})(function() {
    "use strict";

///////////////////////////////////////////////////////////////////////////////
//// DECLARATIONS

    var Logger = {

        LOG_LEVEL : {
            DEBUG : 4,
            INFO : 3,
            ERROR : 1,
            NEVER : 0
        },

        log_level : 0,

        alert : false,

        debug_dump : function(arg_name, arg) {
            if (this.log_level >= this.LOG_LEVEL.DEBUG) {
                debug_dump(arg_name, arg);
            }
        },

        debug_trace : function(msg) {
            if (this.log_level >= this.LOG_LEVEL.DEBUG) {
                debug_trace(msg);
            }
        },

        debug_begins : function(arg) {
            this.debug_trace(">> `" + arg + "` begins...");
        },

        debug_completed : function(arg) {
            this.debug_trace("<< `" + arg + "` completed. ('_')");
        },

        debug_succeeded : function(arg) {
            this.debug_trace("<< `" + arg + "` succeeded. (^_^)");
        },

        debug_failed : function(arg) {
            this.debug_trace("<< `" + arg + "` FAILED! (;_;)");
        },

        error_abend : function(exp) {
            if (this.log_level >= this.LOG_LEVEL.ERROR) {
                error(exp);
            }
            throw "OOPS! APPLICATION ABENDED";
        }
    };

    return Logger;

///////////////////////////////////////////////////////////////////////////////
//// PRIVATE

function debug_dump(arg_name, arg) {
    if (_.isObject(arg)) {
        console.log(format_log("DEBUG", arg_name + " = (shown in below)"));
        console.dir(arg);
    } else if (_.isString(arg)) {
        console.log(format_log("DEBUG", arg_name + " = \"" + arg + "\""));
    } else {
        console.log(format_log("DEBUG", arg_name + " = " + arg));
    }
}

function debug_trace(msg) {
    console.log(format_log("DEBUG", msg || ""));
}

function error(exp) {
    console.error(format_log("ERROR", exp));
    if (Logger.alert) {
        alert("[ERROR] " + exp);
    }
}

function format_log(log_level, msg) {
    var tms = new Date().toString();
    return "[" + tms + "][" + log_level + "] : " + msg;
}

///////////////////////////////////////////////////////////////////////////////
//// (FIN)

});
	<!DOCTYPE html>
	<html>
	<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
	<meta http-equiv="Pragma" content="no-cache">
	<meta http-equiv="Cache-Control" content="no-cache">
	<meta http-equiv="Expires" content="0">
	<title>Logger Module Experiment</title>
	</head>
	<body>
	<h1>Logger Module Experiment</h1>
	<p>
	See the output on the web console.
	</p>
	<!-- SCRIPTS -->
	<script src="http://code.jquery.com/jquery-1.11.3.min.js"></script>
	<script src="http://underscorejs.org/underscore-min.js"></script>
	<script src="js/logger.js"></script>
	<script>
	Logger.log_level = Logger.LOG_LEVEL.DEBUG;
	Logger.alert = true;
	Logger.debug_dump("a string", "hoge");
	Logger.debug_dump("an integer", 123);
	Logger.debug_dump("a boolean", true);
	Logger.debug_dump("an object", {x:1,y:"foo",z:{a:2,b:false}});
	Logger.debug_dump("an object", new Date());
	Logger.debug_trace("run through here");
	Logger.debug_begins("my procedure");
	Logger.debug_completed("my procedure");
	Logger.debug_succeeded("my procedure");
	Logger.debug_failed("my procedure");
	try {
	xxxxx;
	} catch (exp) {
	Logger.error_abend(exp);
	}
	</script>
	<!-- /SCRIPTS -->
	</body>
	</html>
	/*
	* LOGGER
	*/
	; (function(module_def) {
	var MODULE_NAME = "Logger";
	try {
	console.log(">> loading '" + MODULE_NAME + "' begins...");
	var export_target = this;
	export_target[MODULE_NAME] = module_def();
	// TODO more precise exporting procedure
	console.log("<< loading '" + MODULE_NAME + "' succeeded. (^_^)");
	} catch (exp) {
	console.error("<< loading '" + MODULE_NAME + "' FAILED! (T_T) : " + exp);
	console.dir(exp);
	}
	})(function() {
	"use strict";

	///////////////////////////////////////////////////////////////////////////////
	//// DECLARATIONS

	var Logger = {

	LOG_LEVEL : {
	DEBUG : 4,
	INFO : 3,
	ERROR : 1,
	NEVER : 0
	},

	log_level : 0,

	alert : false,

	debug_dump : function(arg_name, arg) {
	if (this.log_level >= this.LOG_LEVEL.DEBUG) {
	debug_dump(arg_name, arg);
	}
	},

	debug_trace : function(msg) {
	if (this.log_level >= this.LOG_LEVEL.DEBUG) {
	debug_trace(msg);
	}
	},

	debug_begins : function(arg) {
	this.debug_trace(">> `" + arg + "` begins...");
	},

	debug_completed : function(arg) {
	this.debug_trace("<< `" + arg + "` completed. ('_')");
	},

	debug_succeeded : function(arg) {
	this.debug_trace("<< `" + arg + "` succeeded. (^_^)");
	},

	debug_failed : function(arg) {
	this.debug_trace("<< `" + arg + "` FAILED! (;_;)");
	},

	error_abend : function(exp) {
	if (this.log_level >= this.LOG_LEVEL.ERROR) {
	error(exp);
	}
	throw "OOPS! APPLICATION ABENDED";
	}
	};

	return Logger;

	///////////////////////////////////////////////////////////////////////////////
	//// PRIVATE

	function debug_dump(arg_name, arg) {
	if (_.isObject(arg)) {
	console.log(format_log("DEBUG", arg_name + " = (shown in below)"));
	console.dir(arg);
	} else if (_.isString(arg)) {
	console.log(format_log("DEBUG", arg_name + " = \"" + arg + "\""));
	} else {
	console.log(format_log("DEBUG", arg_name + " = " + arg));
	}
	}

	function debug_trace(msg) {
	console.log(format_log("DEBUG", msg \|\| ""));
	}

	function error(exp) {
	console.error(format_log("ERROR", exp));
	if (Logger.alert) {
	alert("[ERROR] " + exp);
	}
	}

	function format_log(log_level, msg) {
	var tms = new Date().toString();
	return "[" + tms + "][" + log_level + "] : " + msg;
	}

	///////////////////////////////////////////////////////////////////////////////
	//// (FIN)

	});