The boilerplate logger is a static class for logging to the console or collecting log entries and sending them to a backend service for DB storage. This logger "copies" the functionality and basic principle of the Winston Logger.

All errors within the application should already be using the Logger for errors in the ErrorHandlerService.

The logging levels are determined by an enum defined in the logger.interface.ts file. This enum does not define string values for the levels and the order of those levels is important. For example, if you define a LOG_LEVEL of info. The value of info is 2. So any logging events with a level of info(2), warn(1) or error(0) will be logged (LogLevel <= LOG_LEVEL).

To configure the logger for your system. The following properties/variables need to be defined:

• environment - LOG_LEVEL: Defines the application's logging level and is defined in src/environments/environment.*.ts
• logger.ts - httpTransportPersistLevels: Defines the log entry level that should be persisted to the database, default is error only
• logger.ts - transports: Defines the transports to use
• *-transport.ts - logWithDate: If true will include the current date in the logging message sent to the console/server
• *-transport.ts - shouldPersist: If true means entries should be persisted to the DB
• *-transport.ts - shouldNotifyUser: If true a modal with the error inside it will be shown to the user
• http-transport.ts - flushThreshold: When the number of messages reaches the number defined here, go ahead and flush the que even if the set flushIntervalMs hasn't been met
• http-transport.ts - flushIntervalMs: The number of milliseconds to wait before sending all the collected log entries to the server
• http-transport.ts - In the flush method, define the path to your api service endpoint where to send logs to

There are multiple ways to use the logger, you can call Logger.<LogLevel>(<msg>, param1, param2, ...) or Logger.log(LogLevel.<level>, <msg>, param1, param2, ...). You can include any number of parameters (param).

Here are some example usages of the logger:

import {LogLevel} from 'src/app/core/services/logger/logger.interface';

const someObj = {foo: 'bar', bar: 'baz'};
const someOtherObj = {baz: 'bar', bar: 'foo'};
const err = new Error('Some error');
Logger.info('an info message', someObj);
Logger.debug('a debug message', someObj, someOtherObj);
Logger.error('some error occurred', err, someObj);
Logger.log(LogLevel.error, err.message, err);