Logging

Class: Zetta.Logger

The logger class gives Zetta developer access to printing nicely formatted messages to STDOUT or STDERR. You can also replace Zetta logging with a custom logger such as bunyan or winston.

The logger itself is accessible anywhere you would write code in Zetta. Below are examples on how to access Zetta logging from different types of files.

Device

MyDevice.prototype.init = function(config) {
  this.info('some info message', { hello: 'world'});
};

App

module.exports = function(server) {
  server.info('some info message', { hello: 'world'});
};

Scout

MyScout.prototype.init = function(next) {
  this.server.info('some info message', { hello: 'world'});
};

Method: Logger#info

• message String
• data Object

info will print a standard blue log message to the console output. message is the particular message to be printed, and data is any relevant accompanying data.

server.info('Hello world', { 'hello': 'world' });

Method: Logger#warn

• message String
• data Object

warn will print a standard yellow log message to the console output. message is the particular message to be printed, and data is any relevant accompanying data.

server.warn('Hello world', { 'hello': 'world' });

Method: Logger#error

• message String
• data Object

error will print a standard red log message to the console output. message is the particular message to be printed, and data is any relevant accompanying data.

server.error('Hello world', { 'hello': 'world' });

Method: Logger#log(message, data)

• message String
• data Object

log will print a standard blue log message to the console output. message is the particular message to be printed, and data is any relevant accompanying data. Is a copy of .info()

server.log('Hello world', { 'hello': 'world' });

Custom Logging

Zetta allows to setup log message interception for using custom loggers.

On the Zetta server use the .logger() function to set this up. An example is below.

zetta()
  .logger(function(log) {
    //log is an event emitter

    log.on('message', function(level, event, msg, data) {
      //Fires for any log message  
    });  

    log.on('info', function(event, msg, data) {
      //info event  
    });

    log.on('warn', function(event, msg, data) {
      //warn event
    });

    log.on('error', function(event, msg, data) {
      //error event
    });
  })

Logging suppression

Zetta can also suppress logs using the .silent() method.

//Logs no longer printed.
zetta()
  .silent()
  .listen(3000);