koa-router
引入koa-router这个middleware，让它负责处理URL映射。
在package.json中添加依赖项：
注意加逗号,
"koa-router": "7.0.0"
命令行
npm install
‘use strict’;
const Koa = require('koa');
// 注意require('koa-router')返回的是函数:
const router = require('koa-router')();
const app = new Koa();
// log request URL:
app.use(async (ctx, next) => {
console.log(`Process ${ctx.request.method} ${ctx.request.url}...`);
await next();
});
// add url-route:
router.get('/hello/:name', async (ctx, next) => {
var name = ctx.params.name;
ctx.response.body = `<h1>Hello, ${name}!</h1>`;
});
router.get('/', async (ctx, next) => {
ctx.response.body = '<h1>Index</h1>';
});
// add router middleware:
app.use(router.routes());
app.listen(3000);
console.log('app started at port 3000...');
()是函数调用：
const router = require('koa-router')();
相当于
const fn_router = require('koa-router');
const router = fn_router();
运行app.js
Paste_Image.png
http://localhost:3000/hello/koa
Paste_Image.png
处理post请求
koa-bodyparser
解析原始request请求，然后，把解析后的参数，绑定到ctx.request.body中。
"koa-bodyparser": "3.2.0"
const bodyParser = require('koa-bodyparser');
app.use(bodyParser()); //app.use(router.routes());前调用
'use strict';
const Koa = require('koa');
const router = require('koa-router')();
const bodyParser = require('koa-bodyparser');
const app = new Koa();
app.use(async (ctx, next) => {
console.log(`Process ${ctx.request.method} ${ctx.request.url}....`);
await next();
});
router.get('/', async (ctx, next) => {
ctx.response.body = `<h1>Index</h1>
<form action="/signin" method="post">
<p>Name: <input name="name" value="koa"></p>
<p>Password: <input name="password" type="password"></p>
<p><input type="submit" value="Submit"></p>
</form>`;
});
router.post('/signin', async (ctx, next) => {
var
name = ctx.request.body.name || '',
password = ctx.request.body.password || '';
console.log(`signin with name: ${name}, password: ${password}`);
if (name === 'koa' && password === '12345') {
ctx.response.body = `<h1>Welcome, ${name}!</h1>`;
} else {
ctx.response.body = `<h1>Login failed!</h1>
<p><a href="/">Try again</a></p>`;
}
});
app.use(bodyParser());
app.use(router.routes());
app.listen(3000);
console.log('app started at port 3000');
url-koa
package.json
{
"name": "url-koa",
"version": "1.0.0",
"description": "koa2 example with url route",
"main": "app.js",
"scripts": {
"start": "node --use_strict app.js"
},
"keywords": [
"koa",
"async"
],
"author": "Michael Liao",
"license": "Apache-2.0",
"repository": {
"type": "git",
"url": "https://github.com/michaelliao/learn-javascript.git"
},
"dependencies": {
"koa": "2.0.0",
"koa-bodyparser": "3.2.0",
"koa-router": "7.0.0"
}
}
app.js
const Koa = require('koa');
const bodyParser = require('koa-bodyparser');
const router = require('koa-router')();
const app = new Koa();
// log request URL:
app.use(async (ctx, next) => {
console.log(`Process ${ctx.request.method} ${ctx.request.url}...`);
await next();
});
// parse request body:
app.use(bodyParser());
// add url-route:
router.get('/hello/:name', async (ctx, next) => {
var name = ctx.params.name;
ctx.response.body = `<h1>Hello, ${name}!</h1>`;
});
router.get('/', async (ctx, next) => {
ctx.response.body = `<h1>Index</h1>
<form action="/signin" method="post">
<p>Name: <input name="name" value="koa"></p>
<p>Password: <input name="password" type="password"></p>
<p><input type="submit" value="Submit"></p>
</form>`;
});
router.post('/signin', async (ctx, next) => {
var
name = ctx.request.body.name || '',
password = ctx.request.body.password || '';
console.log(`signin with name: ${name}, password: ${password}`);
if (name === 'koa' && password === '12345') {
ctx.response.body = `<h1>Welcome, ${name}!</h1>`;
} else {
ctx.response.body = `<h1>Login failed!</h1>
<p><a href="/">Try again</a></p>`;
}
});
// add router middleware:
app.use(router.routes());
app.listen(3000);
console.log('app started at port 3000...');
url2-koa
package.json
{
"name": "url2-koa",
"version": "1.0.0",
"description": "koa 2 example with url route",
"main": "app.js",
"scripts": {
"start": "node --use_strict app.js"
},
"keywords": [
"koa",
"async"
],
"author": "Michael Liao",
"license": "Apache-2.0",
"repository": {
"type": "git",
"url": "https://github.com/michaelliao/learn-javascript.git"
},
"dependencies": {
"koa": "2.0.0",
"koa-bodyparser": "3.2.0",
"koa-router": "7.0.0"
}
}
controllers
hello.js
var fn_hello = async (ctx, next) => {
var name = ctx.params.name;
ctx.response.body = `<h1>Hello, ${name}!</h1>`;
};
module.exports = {
'GET /hello/:name': fn_hello
};
index.js
var fn_index = async (ctx, next) => {
ctx.response.body = `<h1>Index</h1>
<form action="/signin" method="post">
<p>Name: <input name="name" value="koa"></p>
<p>Password: <input name="password" type="password"></p>
<p><input type="submit" value="Submit"></p>
</form>`;
};
var fn_signin = async (ctx, next) => {
var
name = ctx.request.body.name || '',
password = ctx.request.body.password || '';
console.log(`signin with name: ${name}, password: ${password}`);
if (name === 'koa' && password === '12345') {
ctx.response.body = `<h1>Welcome, ${name}!</h1>`;
} else {
ctx.response.body = `<h1>Login failed!</h1>
<p><a href="/">Try again</a></p>`;
}
};
module.exports = {
'GET /': fn_index,
'POST /signin': fn_signin
};
controller.js
const fs = require('fs');
// add url-route in /controllers:
function addMapping(router, mapping) {
for (var url in mapping) {
if (url.startsWith('GET ')) {
var path = url.substring(4);
router.get(path, mapping[url]);
console.log(`register URL mapping: GET ${path}`);
} else if (url.startsWith('POST ')) {
var path = url.substring(5);
router.post(path, mapping[url]);
console.log(`register URL mapping: POST ${path}`);
} else if (url.startsWith('PUT ')) {
var path = url.substring(4);
router.put(path, mapping[url]);
console.log(`register URL mapping: PUT ${path}`);
} else if (url.startsWith('DELETE ')) {
var path = url.substring(7);
router.del(path, mapping[url]);
console.log(`register URL mapping: DELETE ${path}`);
} else {
console.log(`invalid URL: ${url}`);
}
}
}
function addControllers(router, dir) {
fs.readdirSync(__dirname + '/' + dir).filter((f) => {
return f.endsWith('.js');
}).forEach((f) => {
console.log(`process controller: ${f}...`);
let mapping = require(__dirname + '/' + dir + '/' + f);
addMapping(router, mapping);
});
}
module.exports = function (dir) {
let
controllers_dir = dir || 'controllers',
router = require('koa-router')();
addControllers(router, controllers_dir);
return router.routes();
};
app.js
const Koa = require('koa');
const bodyParser = require('koa-bodyparser');
const controller = require('./controller');
const app = new Koa();
// log request URL:
app.use(async (ctx, next) => {
console.log(`Process ${ctx.request.method} ${ctx.request.url}...`);
await next();
});
// parse request body:
app.use(bodyParser());
// add controllers:
app.use(controller());
app.listen(3000);
console.log('app started at port 3000...');
