17koa/koa-guide

Name: koa-guide

Owner: 17koa

Description: koa guide in Chinese

Created: 2016-05-04 11:22:38.0

Updated: 2017-10-30 07:20:32.0

Pushed: 2015-11-16 12:47:02.0

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Size: 268

Language: null

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README

????  

Koa???? Node.js web ??

koa ??

? Express ??????? koa?????????????????????? Web ????? koa ?? web ?????????? generator????????????????????????????????Koa ???????????????????????????????????? Web ?????????

?? koa

koa ???? generator ? Node ????????? node >= 0.11.9 ???????????????? Node ????????? n ??????????????? 0.11.x:

m install -g n
0.11
de --harmony my-koa-app.js

??????????? $ node --harmony app.js ??harmony ???????

???????? node ??????? harmony ??????

s node='node --harmony'

---

???Application?

?? Koa Application????? app????? generator ????????????????????????????Koa app ??????????? Ruby Rack ?? Connect/Express ??????????????????????Koa ????????????????????????????????????????

????????????????content-negotation???????cache freshness???????proxy support?????????????????? ??? ?????????? Koa ???????????????????? Koa ????? Hello World ?????

koa = require('koa');
app = koa();

use(function *(){
is.body = 'Hello World';


listen(3000);

????Koa 2???

Koa = require('koa');
app = new Koa();

use(ctx => {
x.body = 'Hello World';


listen(3000);

???? ???? function ???generator functions ? function* ???????????????? yield?generator function?ECMAScript 6???????????????????Koa????generator function?????js?????????????????????????????

---

?????Cascading?

Koa ???????????????????????????????

???? Node ????????????????????????? Koa ????????????????????? Connect ????????????Koa ?????????????????????????????????Koa ?????????????????????????? yield next ?????????????????????downstream??? yield next ???????????????????????upstream??

???????????????????? Hello World ?????????????? x-response-time ???? logging ?????????????????????????? response ??????????????? ?Hello World??

?????? yield next ??????????????????????????????????????????????????????? downstream???????????? downstream ?????????????

koa = require('koa');
app = koa();

-response-time
use(function *(next){
 (1) ????
r start = new Date;
eld next;
 (5) ???? x-response-time ??????2??????????????
r ms = new Date - start;
is.set('X-Response-Time', ms + 'ms');
 (6) ?? this.body


ogger
use(function *(next){
 (2) ?? logger ???
r start = new Date;
eld next;
 (4) ???? logger ??????2??????????????
r ms = new Date - start;
nsole.log('%s %s - %s', this.method, this.url, ms);


esponse
use(function *(){
 (3) ?? response ???????????????????????? upstream
is.body = 'Hello World';


listen(3000);

??????????????????????????????????????????????????????????????????

???? ????????????? CSS ???????????????????????????????????? LESS ??????????

dleware1 {
 (1) do some stuff
iddleware2 {
// (2) do some other stuff
.middleware3 {
  // (3) NO next yield !
  // this.body = 'hello world'
}
// (4) do some other stuff later

 (5) do some stuff lastest and return

???????????????????????????? ruby ??????block?? yield ????????????????? koa ??????

???? ?????????? Django Middleware

---

?????Settings?

?????? app ???????????Koa ???????

• app.name ????
• app.env ???????? NODE_ENV ?? "development" ???
• app.proxy ????? proxy header ???????????
• app.subdomainOffset ???? .subdomains ??????? api

---

????Middleware?

• koa-router
• trie-router
• route
• basic-auth
• etag
• compose
• static
• static-cache
• session
• compress
• csrf
• logger
• mount
• send
• error

---

????

app.listen(…)

????????????????????? 3000 ???????????

koa = require('koa');
app = koa();

listen(3000);

app.listen ? http.createServer ???????????????

http = require('http');
koa = require('koa');
app = koa();

.createServer(app.callback()).listen(3000);

??????????????????? app??????? HTTP ? HTTPS?

http = require('http');
koa = require('koa');
app = koa();

.createServer(app.callback()).listen(3000);
.createServer(app.callback()).listen(3001);

app.callback()

?????? http.createServer() ??????????????????????? Connect/Express ????

app.use(function)

???? function ?????????????? ??? ??

app.keys=

?????? Cookie ????????????? KeyGrip ???????????????????

keys = ['im a newer secret', 'i like turtle'];
keys = new KeyGrip(['im a newer secret', 'i like turtle'], 'sha256');

???????????? signed ??????????

.cookies.set('name', 'tobi', { signed: true });

?????Error Handling?

?? NODE_ENV ???? "test"?Koa ????????????? stderr???????????????? Koa app ????????????????

on('error', function(err){
g.error('server error', err);

??? req ?? res ?????????????????Koa ??????????????????

on('error', function(err, ctx){
g.error('server error', err, ctx);

????????????????????????? socket ??Koa ??????? 500 ???????? app ???????????????

---

??????Context?

Koa ??????? request ? response ??????????????????????????????????????? ctx.request ? ctx.response ?????????

??????????????????????????????????? this ????

use(function *(){
is; // ?????
is.request; // Request ??
is.response; // Response ??

??????????????????????????? ctx.request ? ctx.response????? ctx.type ? ctx.length ????? response ???ctx.path ? ctx.method ????? request ???

Request ??

ctx.request ???????????????? Request ??

• ctx.header
• ctx.method
• ctx.method=
• ctx.url
• ctx.url=
• ctx.path
• ctx.path=
• ctx.query
• ctx.query=
• ctx.querystring
• ctx.querystring=
• ctx.length
• ctx.host
• ctx.fresh
• ctx.stale
• ctx.socket
• ctx.protocol
• ctx.secure
• ctx.ip
• ctx.ips
• ctx.subdomains
• ctx.is()
• ctx.accepts()
• ctx.acceptsEncodings()
• ctx.acceptsCharsets()
• ctx.acceptsLanguages()
• ctx.get()

Response ??

ctx.response ???????????????? Response ??

• ctx.body
• ctx.body=
• ctx.status
• ctx.status=
• ctx.length=
• ctx.type
• ctx.type=
• ctx.headerSent
• ctx.redirect()
• ctx.attachment()
• ctx.set()
• ctx.remove()
• ctx.lastModified=
• ctx.etag=

????????? API

• ctx.req: Node.js ?? request ??
• ctx.res: Node.js ?? response ??????:
• res.statusCode
• res.writeHead()
• res.write()
• res.end()
• ctx.app: app ??
• ctx.state: ????????????????????????????????? this.state.user = yield User.find(id);
• ctx.cookies.get(name, [options]) ????? name ?????? cookie
• options
  • signed [boolean]
• ctx.cookies.set(name, value, [options]) ????????????? cookie
• options
  • signed [boolean]
  • expires [date]
  • path [string] ??? '/'
  • domain [string]
  • secure [boolean]
  • httpOnly [boolean] ??? true
• ctx.throw(msg, [status]) ?????????????? status ? 500?

??????????

.throw(403)
.throw('name required', 400)
.throw(400, 'name required')
.throw('something exploded')

????this.throw('name required', 400) ????????????

err = new Error('name required');
status = 400;
w err;

???????ctx.throw ??????????????????err.expose???????????

• ctx.assert(value, [msg], [status], [properties]) ???????????? Node ?? assert() ???this.assert(this.user, 401, 'User not found. Please login!'); ???? http-assert ?????

---

Request

ctx.request ???? Node ?????????????????????????

??? Request ?? API ???

req.header

?????

req.method

??????

req.method=

?? req.method ??????? methodOverride() ????

req.length

?? req ??? Content-Length (Number)

req.url

???? url

req.url=

???? url????? url ??

req.path

???? pathname

req.path=

???? pathname????? url ????????????????

req.querystring

?? url ?????????????? '?'

req.querystring=

??????????? '?'

req.search

?? url ?????????????? '?'

req.search=

?????????? '?'

req.host

??????????????? app.proxy ??? true ???? X-Forwarded-Host?

req.type

?? req ??? Content-Type???? charset ????????

ct = this.type;
> "image/png"

req.query

??????????????? Express ?? req.query??????????????????

? url ??????? "color=blue&size=small" ???????

lor: 'blue',
ze: 'small'

req.query=

????????????????????

.query = { next: '/login' };

req.fresh

??????????????????????????????????? 304????????

.set('ETag', '123');

?????????
this.fresh) {
is.status = 304;
turn;


?????????????????
.body = yield db.find('something');

req.stale

? req.fresh ?????????

req.protocol

????????? "https" ?? "http"?? app.proxy ??? true ???? X-Forwarded-Proto?

req.secure

????????? HTTPS ????????? this.protocol == "https"

req.ip

????IP?? app.proxy ??? true ???? X-Forwarded-For?

req.ips

????IP????? app.proxy ??? true ???? X-Forwarded-For ????????????

req.subdomains

???????????????????????????????? . ????????????? app.subdomainOffset ??????????????????????

????????? "tobi.ferrets.example.com" ????? ["ferrets", "tobi"]????????????????????

????????????? app.subdomainOffset ? 3??????????? ["tobi"]?

req.is(type)

??????? Content-Type ????? type ??????????? request.body???? undefined????????????? false?????????????????

?? Content-Type: text/html; charset=utf-8
.is('html'); // => 'html'
.is('text/html'); // => 'text/html'
.is('text/*', 'text/html'); // => 'text/html'

?? Content-Type ? application/json ??
.is('json', 'urlencoded'); // => 'json'
.is('application/json'); // => 'application/json'
.is('html', 'application/*'); // => 'application/json'

.is('html'); // => false

?????????? req.is(type)?????????????????

this.is('image/*')) {
 process
se {
is.throw(415, 'images only!');

req.accepts(type)

??????? Accept ????? type ?????????????????????????????? false??????????? 406 “Not Acceptable” ?????????????????

ccept: text/html
.accepts('html');
> "html"

ccept: text/*, application/json
.accepts('html');
> "html"
.accepts('text/html');
> "text/html"
.accepts('json', 'text');
> "json"
.accepts('application/json');
> "application/json"

ccept: text/*, application/json
.accepts('image/png');
.accepts('png');
> undefined

ccept: text/*;q=.5, application/json
.accepts(['html', 'json']);
.accepts('html', 'json');
> "json"

??????????? Accept ?????????? type ??????

req.acceptsEncodings(encodings)

?????????????????????????????????????????????

ccept-Encoding: gzip
.acceptsEncodings('gzip', 'deflate');
> "gzip"

.acceptsEncodings(['gzip', 'deflate']);
> "gzip"

????????????????????

ccept-Encoding: gzip, deflate
.acceptsEncodings();
> ["gzip", "deflate"]

req.acceptsCharsets(charsets)

????? req.acceptsEncodings(encodings)

req.acceptsLanguages(langs)

????? req.acceptsEncodings(encodings)

---

Response

??? Response ?? API ???

res.header

?????

res.status

??????

res.status=

??????????????

• 100 “continue”
• 101 “switching protocols”
• 102 “processing”
• 200 “ok”
• 201 “created”
• 202 “accepted”
• 203 “non-authoritative information”
• 204 “no content”
• 205 “reset content”
• 206 “partial content”
• 207 “multi-status”
• 300 “multiple choices”
• 301 “moved permanently”
• 302 “moved temporarily”
• 303 “see other”
• 304 “not modified”
• 305 “use proxy”
• 307 “temporary redirect”
• 400 “bad request”
• 401 “unauthorized”
• 402 “payment required”
• 403 “forbidden”
• 404 “not found”
• 405 “method not allowed”
• 406 “not acceptable”
• 407 “proxy authentication required”
• 408 “request time-out”
• 409 “conflict”
• 410 “gone”
• 411 “length required”
• 412 “precondition failed”
• 413 “request entity too large”
• 414 “request-uri too large”
• 415 “unsupported media type”
• 416 “requested range not satisfiable”
• 417 “expectation failed”
• 418 “i'm a teapot”
• 422 “unprocessable entity”
• 423 “locked”
• 424 “failed dependency”
• 425 “unordered collection”
• 426 “upgrade required”
• 428 “precondition required”
• 429 “too many requests”
• 431 “request header fields too large”
• 500 “internal server error”
• 501 “not implemented”
• 502 “bad gateway”
• 503 “service unavailable”
• 504 “gateway time-out”
• 505 “http version not supported”
• 506 “variant also negotiates”
• 507 “insufficient storage”
• 509 “bandwidth limit exceeded”
• 510 “not extended”
• 511 “network authentication required”

res.length=

?????? Content-Length ??

res.length

?????? Content-Length ??????? Content-Length ?????? res.body ??

res.body

?? res.body?? res.body ? null ???????? 200 ??koa ???? 404 ???

res.body=

??????????????????????

• string

  Content-Type ?????? text/html ?? text/plain??????? utf-8?Content-Length ??????

• Buffer

  Content-Type ?????? application/octet-stream?Content-Length ??????

• Stream

  Content-Type ?????? application/octet-stream

• Object

  Content-Type ?????? application/json ??????json???????????????json??????????????app.jsonSpaces = 0

• null

res.get(field)

?????????????????????

etag = this.get('ETag');

res.set(field, value)

?????????????????

.set('Cache-Control', 'no-cache');

res.set(fields)

???????????????????

.set({
tag': '1234',
ast-Modified': date

res.remove(fields)

??????????

res.type

??????? Content-Type???? "charset" ????

ct = this.type;
> "image/png"

res.type=

???????????????? Content-Type

.type = 'text/plain; charset=utf-8';
.type = 'image/png';
.type = '.png';
.type = 'png';

??????????????koa ????????????????????? res.type = 'html' ??koa ????? "utf-8" ?????????? res.type = 'text/html' ????koa ??????????

res.redirect(url, [alt])

???? 302 ?????? url?????????? back ????? url ???????refer?????????????????? '/'

.redirect('back');
.redirect('back', '/index.html');
.redirect('/login');
.redirect('http://google.com');

??????? 302 ??????????????????????

.status = 301;
.redirect('/cart');
.body = 'Redirecting to shopping cart';

res.attachment([filename])

?????? Content-Disposition ? "attachment"????????????

res.headerSent

?????????????????????????????????????

res.lastModified

???????? Last-Modified ????????

res.lastModified=

??????? Last-Modified ???????????????????

.response.lastModified = new Date();

res.etag=

?????? Etag ???koa ????? Etag ??????

.response.etag = crypto.createHash('md5').update(this.body).digest('hex');

---

???Benchmarks?

???????????wrk ?? benchmarks ???

ddleware
.03

ddleware
.10

iddleware
.55

iddleware
.92

iddleware
.33

iddleware
.17

iddleware
.98

middleware
.37

?????????????50??????????????????? 340,260 ??/???? 20,415,600 ??/??????? 4.4 ? ??/??

---

????

???????? koa ?????????????????????

• GitHub repository
• Examples
• Middleware
• Wiki
• G+ Community
• Mailing list
• Guide
• FAQ

---

Contributing

• Fork this repo
• Clone your repo
• Install dependencies
• Checkout a feature branch
• Feel free to add your features
• Make sure your features are fully tested
• Open a pull request, and enjoy <3

MIT license

Copyright (c) 2013 turing <o.u.turing@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.

---

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