Skip to contents

Event emitter is inspired by multiple implementation in JavaScript

Source: R/EventEmitter.R
EventEmitter.Rd

it can be used indepentely of battery events to send data from one component to different one, without the need to broadcast and emit events it can be used with services, in addition to can also be used as reactive values in shiny reactive context like renderUI or battery component render function

Methods

Documentation

For full documentation of each method go to https://stash.intranet.roche.com/stash/projects/DIVOS/repos/battery/browse

EventEmitter$new(...)

This method is used to create EventEmitter

on

Method add new handler for given event

emit

Method emit event add trigger all handlers added by on

off

Method removes single handler or all handlers and observer of no handler left

finalize

Destructor - clean up the data

Public fields

.calls

- if EventEmitter is created with spy = TRUE it will add method calls to this list

events

- environment with reactive objects if EventEmitter created wtih shiny = TRUE, otherwise it's normal environment but with R active bindings that can't be used in shiny render functions

Methods

Public methods

Method new()

R6Class destructor. Cleans up event handlers

R6Class Constructor. If shiny option is used it will create ReactiveBinding with hack that always trigger reactive context (the same cases the component events - this is shiny bug)

Usage

EventEmitter$new(spy = FALSE, shiny = FALSE)

Arguments

spy

- if set to TRUE it will log all method calls - for debugging

shiny

- use this option if you need reactive value to trigger render handlers in shiny

Method on()

Method add new handler for given event

create new observer if doesn't exists and add handler to the list to that observer, we use single observer so ... will be of no use on next handler on single event, we keep it just in case it may be of use

Usage

EventEmitter$on(events, handler, ...)

Arguments

events

- string or character vector with name of the events

handler

- function used as handler for give event

...

- used only once for observeEvent if shiny mode is used

Method emit()

Method emit event add trigger all handlers added by on

Usage

EventEmitter$emit(name, data = NULL)

Arguments

name

- character - name of the event to fire

data

- optional data that can be accessed in handler

Method off()

Method removes single handler or all handlers and observer of no handler left

Usage

EventEmitter$off(events, handler = NULL)

Arguments

events

- string or character vector with name of the events to destroy

handler

- optional handler if not NULL it will remove only given handler

Method clone()

The objects of this class are cloneable with this method.

Usage

EventEmitter$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples


e <- EventEmitter$new()
e$on("sessionCreated", function(value) {
  print(value$name)
})

## and in different part of the application

e$emit("sessionCreated", list(name = "My Session"))
#> [1] "My Session"