log-events

A very basic event logger that lets you apply one hook to an event that will log to the provided stream in color.

For simplicity, any event on any emitter can only be hooked once with this app. Multiple hooks on the same event simply result in the previous one being replaced.

Usage

npm install @cool-blue/logevents

Exports a constructor

const  LogEvents = require('@cool-blue/logevents'),

const logEvents = LogEvents()   // outputs to stdout
const logEvents = LogEvents(_validPath_)   // outputs to a file
const logEvents = LogEvents(_writeStream_)   // outputs to a stream

Exposes some utility functions

#.open applies hooks to an event emitter

const events = ['event1', 'event2', 'event3'];

logEvents().open(eventEmitter, events)  // logs the specified events
logEvents().open(eventEmitter, events, 'event2')  // logs all except event2
logEvents().open(eventEmitter, events, ['event2'])  // logs all except event2
logEvents().open(eventEmitter, 'event1')  // logs event1

const objEvents = events.map(function(e){
    return {
        type: e,
        action: function(){ console.log(this.name) },
    }
});

// logs the specified events and performs the specified action
logEvents().open(eventEmitter, objEvents)

const objSomeEvents = someEvents.map(function(e){
    return {
        type: e,
        action: function(){ console.log(this.name) },
        add_remove: false
    }
});

// un-hooks/hooks events if add_remove is true/false
logEvents().open(eventEmitter, objSomeEvents)

#.open.defaultActions([{type: {function}])

sets persistent default actions for indicated event types there are preset default actions on data and end event types to unshift the chunk returned to the listener.

Setting the action to a falsey value will remove the default action for the event type. Adding an action that is already included will replace that action

#.logger provides a few color formatting options to help highlight the output

log.h1(_message_)   // default styles...
log.h2(_message_)
log.h3(_message_)
log.plain()         // without escape sequences (for non-TTY output)
log.fancy()         // to restore the default behaviour of colourised output

The default behaviour is to issue ANSI escape sequences to highlight the different styles.