https://github.com/codeman99/toflush

Node.js Streams - Transform on Flush
https://github.com/codeman99/toflush

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Node.js Streams - Transform on Flush

• Host: GitHub
• URL: https://github.com/codeman99/toflush
• Owner: CodeMan99
• License: isc
• Created: 2018-01-13T05:27:44.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2018-01-13T06:02:14.000Z (almost 7 years ago)
• Last Synced: 2024-09-24T19:43:37.934Z (about 2 months ago)
• Language: JavaScript
• Homepage:
• Size: 9.77 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.md

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README

        
# toflush [![Build Status](https://travis-ci.org/CodeMan99/toflush.svg?branch=master)](https://travis-ci.org/CodeMan99/toflush)

Transform on Flush. Process an entire object mode stream in a single

function call.

## Install

    npm install --save toflush

## Usage

May have a synchronous callback.

    fs.createReadStream('./rows.db') // newline delimited json

      .pipe(split(JSON.parse))

      .pipe(toflush(JSON.stringify))

      .pipe(fs.createWriteStream('./database.json')) // write out as a JSON array

May have a asynchronous, Promise returning, callback.

    fs.createReadStream('./images.db')

      .pipe(split(JSON.parse))

      .pipe(toflush(items => {

        return fetch(items[0].url).then(response => {

          if (response.ok) {

            return response.buffer();

          }

          throw new Error(`${response.status} ${response.statusText}`);

        });

      }))

      .on('error', error => /* handle fetch or response error */)

      .pipe(fs.createWriteStream('./first.png'));

There are more examples available in the documentation and in the test cases.

## API

A single function that receives either an options object or a callback.

### toflush(options) -> stream.Transform

 * `options.callback` - function that receives all objects from the stream

   as the first argument. Should return an object, array, or a promise. More

   detail [below](#toflushcallback---streamtransform).

 * `options.name` - String name to use in error message. Default `toflush`. May

   also be provide by the callback name.

 * `options.stream` - Boolean sanity flag that makes [vinyl][] content streams

   opt-in.

### toflush(callback) -> stream.Transform

Same as the callback in the options above. Any thrown error or rejection is

emitted by the stream.

 * `callback(items) -> Object` - take all objects, and return a single object.

 * `callback(items) -> Object[]` - take all objects, and return any number of

   objects. May be the same, more, or less than the input. Each item is pushed

   into the stream, not the array.

 * `callback(items) -> Promise` - take all objects, and _then_ promise

   a single object.

 * `callback(items) -> Promise` - take all objects, and _then_

   promise any number of objects. May be the same, more, or less than the

   input. Each item is pushed into the stream, not the array.

## Required

You must be using node.js v4.x or later. This module has no dependencies,

taking advantage of the improved `stream.Transform` implementation.

## Related

 * [vinyl][] - virtual file format, used heavily by `gulp`.

 * [get-stream][] - get stream as a string, buffer, or array.

 * [through2][] - older general stream utility. Heavily inspired this project.

 * [vinyl-map][] - vinyl specific tool, processing only file contents.

## License

MIT © Cody A. Taylor 2018

[vinyl]: https://github.com/gulpjs/vinyl "gulpjs/vinyl"

[get-stream]: https://github.com/sindresorhus/get-stream "sindresorhus/get-stream"

[through2]: https://github.com/rvagg/through2 "rvagg/through2"

[vinyl-map]: https://github.com/affirmix/vinyl-map "affirmix/vinyl-map"