on(event, callback)

Register a listener on an event.

Returns : The current StreamHelper object, for chaining.

Throws : An exception if the event is unknown.


name type description
event string the name of the event. Only 3 events are supported : data, end and error.
callback function the function called when the event occurs. See below for the arguments.

The callbacks are executed in with the current StreamHelper as this.

data callback

It takes 2 parameters:

  • the current chunk of data (in a format specified by the method which generated this StreamHelper)
  • the metadata (see each method to know what’s inside)

end callback

It does not take any parameter.

error callback

It takes an Error as parameter.


.on('data', function (data, metadata) {
    // data is a Uint8Array because that's the type asked in generateInternalStream
    // metadata contains for example currentFile and percent, see the generateInternalStream doc.
.on('error', function (e) {
    // e is the error
.on('end', function () {
    // no parameter