koa-lite/Readme.md

251 lines
14 KiB
Markdown
Raw Normal View History

<img src="https://dl.dropboxusercontent.com/u/6396913/koa/logo.png" alt="koa middleware framework for nodejs" width="255px" />
2014-11-30 08:03:09 +00:00
[![gitter][gitter-image]][gitter-url]
2014-07-26 06:43:41 +00:00
[![NPM version][npm-image]][npm-url]
[![build status][travis-image]][travis-url]
[![Test coverage][coveralls-image]][coveralls-url]
[![OpenCollective Backers](https://opencollective.com/koajs/backers/badge.svg)](#backers) [![OpenCollective Sponsors](https://opencollective.com/koajs/sponsors/badge.svg)](#sponsors)
2013-11-08 09:16:26 +00:00
Expressive HTTP middleware framework for node.js to make web applications and APIs more enjoyable to write. Koa's middleware stack flows in a stack-like manner, allowing you to perform actions downstream then filter and manipulate the response upstream.
2013-08-17 07:15:57 +00:00
2015-11-05 16:42:14 +00:00
Only methods that are common to nearly all HTTP servers are integrated directly into Koa's small ~570 SLOC codebase. This
2015-08-23 15:18:54 +00:00
includes things like content negotiation, normalization of node inconsistencies, redirection, and a few others.
2013-08-17 07:15:57 +00:00
2015-08-31 05:07:54 +00:00
Koa is not bundled with any middleware.
2013-08-17 07:15:57 +00:00
## Installation
2017-02-25 06:30:11 +00:00
Koa requires __node v7.6.0__ or higher for ES2015 and async function support.
2013-08-17 07:15:57 +00:00
```
2017-02-25 06:30:11 +00:00
$ npm install koa
2013-08-17 07:15:57 +00:00
```
## Hello koa
2013-08-17 07:15:57 +00:00
```js
const Koa = require('koa');
const app = new Koa();
2013-08-17 07:15:57 +00:00
// response
app.use(ctx => {
ctx.body = 'Hello Koa';
});
app.listen(3000);
```
2013-08-17 07:15:57 +00:00
## Getting started
2014-07-26 06:43:41 +00:00
- [Kick-Off-Koa](https://github.com/koajs/kick-off-koa) - An intro to koa via a set of self-guided workshops.
- [Workshop](https://github.com/koajs/workshop) - A workshop to learn the basics of koa, Express' spiritual successor.
- [Introduction Screencast](http://knowthen.com/episode-3-koajs-quickstart-guide/) - An introduction to installing and getting started with Koa
2014-07-26 06:43:41 +00:00
## Middleware
2016-05-13 06:27:18 +00:00
Koa is a middleware framework that can take 3 different kinds of functions as middleware:
* common function
* async function
* generator function
2016-05-13 06:27:18 +00:00
Here is an example of logger middleware with each of the different functions:
2017-02-25 06:30:11 +00:00
### ___async___ functions (node v7.6+)
```js
app.use(async (ctx, next) => {
const start = new Date();
await next();
const ms = new Date() - start;
console.log(`${ctx.method} ${ctx.url} - ${ms}ms`);
});
```
### Common function
2015-10-23 08:36:13 +00:00
2016-03-15 15:35:52 +00:00
```js
2016-05-13 06:27:18 +00:00
// Middleware normally takes two parameters (ctx, next), ctx is the context for one request,
// next is a function that is invoked to execute the downstream middleware. It returns a Promise with a then function for running code after completion.
2015-10-23 08:36:13 +00:00
app.use((ctx, next) => {
2016-03-15 15:35:52 +00:00
const start = new Date();
2015-10-23 08:36:13 +00:00
return next().then(() => {
2016-03-15 15:35:52 +00:00
const ms = new Date() - start;
2015-11-07 17:09:58 +00:00
console.log(`${ctx.method} ${ctx.url} - ${ms}ms`);
2015-10-23 08:36:13 +00:00
});
});
```
### GeneratorFunction
2015-10-23 08:36:13 +00:00
To use generator functions, you must use a wrapper such as [co](https://github.com/tj/co) that is no longer supplied with Koa.
```js
2016-03-15 15:35:52 +00:00
app.use(co.wrap(function *(ctx, next) {
const start = new Date();
2015-10-23 08:36:13 +00:00
yield next();
2016-03-15 15:35:52 +00:00
const ms = new Date() - start;
2015-11-07 17:09:58 +00:00
console.log(`${ctx.method} ${ctx.url} - ${ms}ms`);
2015-10-23 08:36:13 +00:00
}));
```
### Old signature middleware (v1.x) - Deprecated
**Old signature middleware (v1.x) support will be removed in v3**
Koa v2.x will try to convert legacy signature, generator middleware on `app.use`, using [koa-convert](https://github.com/koajs/convert).
It is however recommended that you choose to migrate all v1.x middleware as soon as possible.
```js
// Koa will convert
app.use(function *(next) {
const start = new Date();
yield next;
const ms = new Date() - start;
console.log(`${this.method} ${this.url} - ${ms}ms`);
});
```
You could do it manually as well, in which case Koa will not convert.
2013-08-17 07:15:57 +00:00
```js
2016-03-15 15:35:52 +00:00
const convert = require('koa-convert');
2013-08-17 07:15:57 +00:00
2016-03-15 15:35:52 +00:00
app.use(convert(function *(next) {
const start = new Date();
2013-11-08 00:31:16 +00:00
yield next;
2016-03-15 15:35:52 +00:00
const ms = new Date() - start;
2015-11-07 17:09:58 +00:00
console.log(`${this.method} ${this.url} - ${ms}ms`);
}));
```
2013-08-17 07:15:57 +00:00
## Babel setup
2016-07-23 17:48:20 +00:00
2017-02-25 06:30:11 +00:00
For Node 4.0+ and Babel 6.0 you can setup like this:
```bash
$ npm install babel-register babel-plugin-transform-async-to-generator --save
2013-08-17 07:15:57 +00:00
```
```js
// set babel in entry file
2016-07-23 17:48:20 +00:00
require('babel-register')({
plugins: ['transform-async-to-generator']
});
```
2016-07-23 17:48:20 +00:00
Check out an example in koa's [test](test/babel/index.js).
2013-08-17 07:15:57 +00:00
## Running tests
```
$ make test
```
2013-08-26 02:16:57 +00:00
## Authors
2015-10-12 07:04:58 +00:00
See [AUTHORS](AUTHORS).
2013-08-26 02:16:57 +00:00
## Community
- [API](docs/api/index.md) documentation
- [Badgeboard](https://koajs.github.io/badgeboard) and list of official modules
- [Examples](https://github.com/koajs/examples)
- [Middleware](https://github.com/koajs/koa/wiki) list
- [Wiki](https://github.com/koajs/koa/wiki)
- [G+ Community](https://plus.google.com/communities/101845768320796750641)
- [Reddit Community](https://www.reddit.com/r/koajs)
- [Mailing list](https://groups.google.com/forum/#!forum/koajs)
- [Guide](docs/guide.md)
- [FAQ](docs/faq.md)
- [中文文档](https://github.com/guo-yu/koa-guide)
- __[#koajs]__ on freenode
## Backers
Support us with a monthly donation and help us continue our activities.
<a href="https://opencollective.com/koajs/backer/0/website" target="_blank"><img src="https://opencollective.com/koajs/backer/0/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/1/website" target="_blank"><img src="https://opencollective.com/koajs/backer/1/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/2/website" target="_blank"><img src="https://opencollective.com/koajs/backer/2/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/3/website" target="_blank"><img src="https://opencollective.com/koajs/backer/3/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/4/website" target="_blank"><img src="https://opencollective.com/koajs/backer/4/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/5/website" target="_blank"><img src="https://opencollective.com/koajs/backer/5/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/6/website" target="_blank"><img src="https://opencollective.com/koajs/backer/6/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/7/website" target="_blank"><img src="https://opencollective.com/koajs/backer/7/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/8/website" target="_blank"><img src="https://opencollective.com/koajs/backer/8/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/9/website" target="_blank"><img src="https://opencollective.com/koajs/backer/9/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/10/website" target="_blank"><img src="https://opencollective.com/koajs/backer/10/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/11/website" target="_blank"><img src="https://opencollective.com/koajs/backer/11/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/12/website" target="_blank"><img src="https://opencollective.com/koajs/backer/12/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/13/website" target="_blank"><img src="https://opencollective.com/koajs/backer/13/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/14/website" target="_blank"><img src="https://opencollective.com/koajs/backer/14/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/15/website" target="_blank"><img src="https://opencollective.com/koajs/backer/15/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/16/website" target="_blank"><img src="https://opencollective.com/koajs/backer/16/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/17/website" target="_blank"><img src="https://opencollective.com/koajs/backer/17/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/18/website" target="_blank"><img src="https://opencollective.com/koajs/backer/18/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/19/website" target="_blank"><img src="https://opencollective.com/koajs/backer/19/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/20/website" target="_blank"><img src="https://opencollective.com/koajs/backer/20/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/21/website" target="_blank"><img src="https://opencollective.com/koajs/backer/21/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/22/website" target="_blank"><img src="https://opencollective.com/koajs/backer/22/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/23/website" target="_blank"><img src="https://opencollective.com/koajs/backer/23/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/24/website" target="_blank"><img src="https://opencollective.com/koajs/backer/24/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/25/website" target="_blank"><img src="https://opencollective.com/koajs/backer/25/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/26/website" target="_blank"><img src="https://opencollective.com/koajs/backer/26/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/27/website" target="_blank"><img src="https://opencollective.com/koajs/backer/27/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/28/website" target="_blank"><img src="https://opencollective.com/koajs/backer/28/avatar.svg"></a>
<a href="https://opencollective.com/koajs/backer/29/website" target="_blank"><img src="https://opencollective.com/koajs/backer/29/avatar.svg"></a>
## Sponsors
Become a sponsor and get your logo on our README on Github with a link to your site.
<a href="https://opencollective.com/koajs/sponsor/0/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/0/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/1/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/1/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/2/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/2/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/3/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/3/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/4/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/4/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/5/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/5/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/6/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/6/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/7/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/7/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/8/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/8/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/9/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/9/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/10/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/10/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/11/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/11/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/12/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/12/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/13/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/13/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/14/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/14/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/15/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/15/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/16/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/16/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/17/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/17/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/18/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/18/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/19/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/19/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/20/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/20/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/21/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/21/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/22/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/22/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/23/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/23/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/24/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/24/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/25/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/25/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/26/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/26/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/27/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/27/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/28/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/28/avatar.svg"></a>
<a href="https://opencollective.com/koajs/sponsor/29/website" target="_blank"><img src="https://opencollective.com/koajs/sponsor/29/avatar.svg"></a>
2013-08-17 07:15:57 +00:00
# License
MIT
2014-10-09 17:59:57 +00:00
[npm-image]: https://img.shields.io/npm/v/koa.svg?style=flat-square
[npm-url]: https://www.npmjs.com/package/koa
2014-10-27 16:42:01 +00:00
[travis-image]: https://img.shields.io/travis/koajs/koa/master.svg?style=flat-square
[travis-url]: https://travis-ci.org/koajs/koa
2016-03-03 22:40:43 +00:00
[coveralls-image]: https://codecov.io/github/koajs/koa/coverage.svg?branch=master
[coveralls-url]: https://codecov.io/github/koajs/koa?branch=master
2014-11-04 16:59:11 +00:00
[gitter-image]: https://badges.gitter.im/Join%20Chat.svg
[gitter-url]: https://gitter.im/koajs/koa?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge
[#koajs]: https://webchat.freenode.net/?channels=#koajs