Package Exports

stream-forward

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (stream-forward) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

stream-forward

Forward events to the next stream in the pipeline.

Use

$ npm install --save stream-forward

var streamForward = require('stream-forward');

Example

var streamForward = require('stream-forward');
var request = require('request');

var opts = {
  events: ['response']
};

streamForward(request('http://yahoo.com'), opts)
  .pipe(process.stdout)
  .on('response', function (response) {
    // `response` from the request stream.
  });

Note: don't neglect proper event handling on the individual parts of your stream.

This is just a convenience when you have to manually listen and re-emit events across a middleman/spy pipe. Consider the following example:

var fs = require('fs');

function getRequestStream(reqOpts) {
  var opts = {
    events: ['complete']
  };

  return streamForward(request(reqOpts), opts)
    .pipe(fs.createWriteStream('./request-cache'));
}

getRequestStream('http://yahoo.com')
  .on('complete', function () {
    // Without `stream-forward`, this couldn't emit.
  });

stream = streamForward(stream, [options]);

stream

Type: Stream

The source stream to spy on. This is returned from the function to allow chaining.

options

Optional. Configuration options.

options.continuous

Type: Boolean
Default: false

If true, when a new stream is attached to stream, it will receive the events emitted by the original.

Disabled (default)

var sourceStream = request('http://yahoo.com');
var through = require('through2');

streamForward(sourceStream)
  .pipe(through())
  .on('complete', function () {
    // Called.
  })
  .pipe(through())
  .on('complete', function () {
    // Not called.
  });

Enabled

var sourceStream = request('http://yahoo.com');
var through = require('through2');

streamForward(sourceStream, { continuous: true })
  .pipe(through())
  .on('complete', function () {
    // Called.
  })
  .pipe(through())
  .on('complete', function () {
    // Called.
  });

options.events

Type: Array

Event names to re-emit on attached streams.