Vmeda.Online/src/providers/logger.ts

74 lines
2.6 KiB
TypeScript

// (C) Copyright 2015 Martin Dougiamas
//
// Licensed 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.
import { Injectable } from '@angular/core';
import * as moment from 'moment';
/**
* Helper service to display messages in the console.
*
* @description
* This service is meant to improve log messages, adding a timestamp and a name to all log messages.
*
* In your class constructor, call getInstance to configure your class name:
* this.logger = logger.getInstance('InitPage');
*
* Then you can call the log function you want to use in this logger instance.
*/
@Injectable()
export class CoreLoggerProvider {
/** Whether the logging is enabled. */
enabled = true;
constructor() {
// Nothing to do.
}
/**
* Get a logger instance for a certain class, service or component.
*
* @param {string} className Name to use in the messages.
* @return {ant} Instance.
*/
getInstance(className: string): any {
className = className || '';
return {
log: this.prepareLogFn(console.log.bind(console), className),
info: this.prepareLogFn(console.info.bind(console), className),
warn: this.prepareLogFn(console.warn.bind(console), className),
debug: this.prepareLogFn(console.debug.bind(console), className),
error: this.prepareLogFn(console.error.bind(console), className)
};
}
/**
* Prepare a logging function, concatenating the timestamp and class name to all messages.
*
* @param {Function} logFn Log function to use.
* @param {string} className Name to use in the messages.
* @return {Function} Prepared function.
*/
private prepareLogFn(logFn: Function, className: string): Function {
// Return our own function that will call the logging function with the treated message.
return (...args): void => {
if (this.enabled) {
const now = moment().format('l LTS');
args[0] = now + ' ' + className + ': ' + args[0]; // Prepend timestamp and className to the original message.
logFn.apply(null, args);
}
};
}
}