streamCb

Convert between node's two most popular interfaces, streams and (err, result) callbacks.

They are both setup to handle data in the future and do something responsible with an error if one occurs. The fundamental difference is that streams can handle chunks at a time, where as callbacks have to handle the whole thing at once. But when interfacing with a module that deals with everything at once we still want to use our streaming magic.

var streamCb = require('stream-cb')

streamCb(?, opt)

if ? is a stream, call .toCb(?, opt) if ? is a function, call .toStream(?, opt) Otherwise return undefined.

streamCb.toStream(cb, encoding)

return a writable stream that calls cb(null, results) if it's ended or with an error if error occurs.

streamCb.toCb(stream, noend)

return a callback that writes to the stream when it's called (null, data), or emits an error if one is provided.

If noend then don't end the stream when the returned callback is called.

Why?

Because you want to make a streams lib and a cb lib work together, or you want to provide a flexible api for your users.

Libs playing together

var client = require('redis').createClient()
  , http = require('http')
  , streamCb = require('stream-cb')
 
client.set('space_cowboys', 'Mal Reynolds, Han Solo, Vash the Stampede')
 
http.createServer(function (req, res) {
 
  res.on('error', function (e) {
    res.statusCode = 500
    res.end('Server ' + e)
  })
 
  res.statusCode = 200
 
  client.get('space_cowboys', streamCb(res))
 
}).listen(8080)

Flexible API

function (opts, cb) {
  var awesome = new crazyStream
  // Do cool streams stuff here
 
  if (cb) return awesome.pipe(streamCb.toStream(cb))
  return awesome
}

License (MIT)

Copyright (c) 2013 Nick Niemeir nick.niemeir@gmail.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.