koa-bodyparser 应用
这里对koa-bodyparser的应用教程。
目录如下
ejs文件
ejs模板文件
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>Title</title></head><body><form action="/doAdd" method="post"> 用户名: <input type="text" name="username"/> 明码: <input type="password" name="password"/> <button type="submit">提交</button></form></body></html>koa-bodyparser
应用koa-bodyparser获取body内容
var koa = require("koa");var Router = require("koa-router");var bodyParser = require("koa-bodyparser");var app = new koa();var router = new Router();var views = require("koa-views");app.use(views("views", { extension: "ejs",}))app.use(bodyParser());// koa中间件app.use(async (ctx, next) => { console.log(new Date()); await next();});router.get("/", async (ctx) => { await ctx.render("index");})router.post("/doAdd", async (ctx) => { console.log(ctx.request.body); ctx.body = ctx.request.body;})app.use(router.routes());app.use(router.allowedMethods());app.listen(3001);应用成果
登录页面
koa-static
这里学习应用koa-static
装置
PS C:\Users\Administrator\Desktop\untitled3> npm install --save koa-staticnpm WARN untitled3@1.0.0 No descriptionnpm WARN untitled3@1.0.0 No repository field.+ koa-static@5.0.0added 1 package in 2.042s2 packages are looking for funding run `npm fund` for detailsPS C:\Users\Administrator\Desktop\untitled3>拜访成果
拜访成果如下
art-template
这里应用art-template 作为一个模板引擎应用
装置
PS C:\Users\Administrator\Desktop\untitled3> npm install --save art-templatenpm WARN untitled3@1.0.0 No descriptionnpm WARN untitled3@1.0.0 No repository field.+ art-template@4.13.2added 33 packages from 141 contributors in 6.704s2 packages are looking for funding run `npm fund` for detailsPS C:\Users\Administrator\Desktop\untitled3> npm install --save koa-art-templatenpm WARN untitled3@1.0.0 No descriptionnpm WARN untitled3@1.0.0 No repository field.+ koa-art-template@1.1.1added 2 packages from 4 contributors in 2.336s2 packages are looking for funding run `npm fund` for details代码如下
var koa = require("koa");var Router = require("koa-router");var bodyParser = require("koa-bodyparser");var static = require("koa-static");var app = new koa();var router = new Router();var views = require("koa-views");var render = require("koa-art-template");var path = require("path");app.use(views("views", { extension: "ejs",}))app.use(static("./static"));app.use(bodyParser());// koa中间件app.use(async (ctx, next) => { console.log(new Date()); await next();});router.get("/", async (ctx) => { await ctx.render("index");})router.post("/doAdd", async (ctx) => { console.log(ctx.request.body); ctx.body = ctx.request.body;})render(app, { root: path.join(__dirname, "views"), extname: ".art",})app.use(async function (ctx){ await ctx.render("user");})app.use(router.routes());app.use(router.allowedMethods());app.listen(3001);art 文件如下
var koa = require("koa");var Router = require("koa-router");var bodyParser = require("koa-bodyparser");var static = require("koa-static");var app = new koa();var router = new Router();var views = require("koa-views");var render = require("koa-art-template");var path = require("path");app.use(views("views", { extension: "ejs",}))app.use(static("./static"));app.use(bodyParser());// koa中间件app.use(async (ctx, next) => { console.log(new Date()); await next();});router.get("/", async (ctx) => { await ctx.render("index");})router.post("/doAdd", async (ctx) => { console.log(ctx.request.body); ctx.body = ctx.request.body;})render(app, { root: path.join(__dirname, "views"), extname: ".art",})app.use(async function (ctx){ await ctx.render("user");})app.use(router.routes());app.use(router.allowedMethods());app.listen(3001);拜访成果
cookie
var koa = require("koa");var Router = require("koa-router");var bodyParser = require("koa-bodyparser");var static = require("koa-static");var app = new koa();var router = new Router();var views = require("koa-views");var render = require("koa-art-template");var path = require("path");app.use(bodyParser());// koa中间件app.use(async (ctx, next) => { console.log(new Date()); await next();});router.get("/", async (ctx) => { ctx.cookies.set("ming", "ming")})app.use(router.routes());app.use(router.allowedMethods());app.listen(3001);koa-session
PS C:\Users\Administrator\Desktop\untitled3> npm install koa-sessionnpm WARN untitled3@1.0.0 No descriptionnpm WARN untitled3@1.0.0 No repository field.+ koa-session@6.0.0added 10 packages from 14 contributors in 3.484s2 packages are looking for funding run `npm fund` for detailsPS C:\Users\Administrator\Desktop\untitled3>编写一个简略的刷新页面次数减少
var koa = require("koa");var Router = require("koa-router");var bodyParser = require("koa-bodyparser");var static = require("koa-static");var app = new koa();var router = new Router();var views = require("koa-views");var render = require("koa-art-template");var path = require("path");var session = require("koa-session");app.keys = ['secret']; // session加密字段app.use(session({ key: 'koa:sess', //cookie key (default is koa:sess) maxAge: 86400000, // cookie的过期工夫 maxAge in ms (default is 1 days) overwrite: true, //是否能够overwrite (默认default true) httpOnly: true, //cookie是否只有服务器端能够拜访 httpOnly or not (default true) signed: true, //签名默认true rolling: false, //在每次申请时强行设置cookie，这将重置cookie过期工夫（默认：false） renew: false, //(boolean) renew session when session is nearly expired,}, app));app.use(bodyParser());// koa中间件app.use(async (ctx, next) => { console.log(new Date()); await next();});app.use(ctx => { // ignore favicon if (ctx.path === '/favicon.ico') return console.log(ctx.session) let n = ctx.session.views || 0 ctx.session.views = ++n ctx.body = n + ' views'});router.get("/", async (ctx) => { ctx.cookies.set("ming", "ming")})app.use(router.routes());app.use(router.allowedMethods());app.listen(3001);原型链继承
// 结构原型function Person(name, age) { this.name = name; this.age = 333; this.run = function () { console.log(this.name, this.age) }}// 增加work办法，在原型链上继承Person.prototype.work = () => { console.log("work");}function Web() {}// 同样继承Web.prototype = new Person();var w = new Web();// 以下两个运行原型链的值w.run();w.work()静态方法和构造方法
// 新建类class Person{ constructor(name) { this._name = name; } run(){ console.log(this._name); } // 静态方法 static work(){ console.log("静态方法"); }}Person.work();koa 操作mongoDB
装置相干的库
PS C:\Users\Administrator\Desktop\untitled3> npm install mongodb --savenpm WARN untitled3@1.0.0 No descriptionnpm WARN untitled3@1.0.0 No repository field.+ mongodb@3.5.9updated 1 package in 2.854s2 packages are looking for funding run `npm fund` for detailsPS C:\Users\Administrator\Desktop\untitled3>减少一条数据
var MongoClient = require("mongodb").MongoClient;var dbUrl = 'mongodb://106.53.115.12:27017/'var dbName = "koa";// 连贯MongoClient.connect(dbUrl, (err, client) => { if(err){ console.log(err); return; } var db = client.db(dbName); // 减少数据 db.collection("user").insertOne({ "username":"xiaoxiao","age":"23" });})后果：
对返回后果进行解决
var MongoClient = require("mongodb").MongoClient;var dbUrl = 'mongodb://106.53.115.12:27017/'var dbName = "koa";// 连贯MongoClient.connect(dbUrl, (err, client) => { if(err){ console.log(err); return; } var db = client.db(dbName); // 减少数据 db.collection("user").insertOne({ "username":"xiaoxiao","age":"23" }, function (err, result) { if(!err){ console.log("减少数据胜利 "); client.close(); console.timeEnd("start"); } });})查问数据
代码如下
var MongoClient = require("mongodb").MongoClient;var dbUrl = 'mongodb://106.53.115.12:27017/'var dbName = "koa";// 连贯MongoClient.connect(dbUrl, (err, client) => { if(err){ console.log(err); return; } var db = client.db(dbName); var result = db.collection("user").find(0); result.toArray((err, docs) => { console.log(docs); })})输入内容如下
"C:\Program Files\nodejs\node.exe" C:\Users\Administrator\Desktop\untitled3\01es6.js(node:15216) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor.[ { _id: 5f0fe666bc0d9e41101dffd3, username: 'xiaoxiao', age: '23' }, { _id: 5f0fe7f4949f1b420c120fe7, username: 'xiaoxiao', age: '23' }]koa 利用生成器
全局装置
应用全局装置koa的脚手架
PS C:\Users\Administrator\Desktop\untitled3> npm install koa-generator -gnpm WARN deprecated mkdirp@0.5.1: Legacy versions of mkdirp are no longer supported. Please update to mkdirp 1.x. (Note that the API surface has changed to use Promises in 1.x.)C:\Users\Administrator\AppData\Roaming\npm\koa -> C:\Users\Administrator\AppData\Roaming\npm\node_modules\koa-generator\bin\koaC:\Users\Administrator\AppData\Roaming\npm\koa2 -> C:\Users\Administrator\AppData\Roaming\npm\node_modules\koa-generator\bin\koa2+ koa-generator@1.1.17updated 1 package in 0.905sPS C:\Users\Administrator\Desktop\untitled3>创立我的项目
PS C:\Users\Administrator\Desktop> ls 目录: C:\Users\Administrator\DesktopMode LastWriteTime Length Name---- ------------- ------ ----d----- 2020/7/14 17:08 insurv-mina-node-apid----- 2020/7/14 17:45 koad----- 2020/7/14 17:55 untitledd----- 2020/7/16 14:16 untitled3-a---- 2020/7/16 12:04 5782870 Navicat Premium 15.x最新注册机.zip-a---- 2020/7/14 17:07 1428 Visual Studio Code.lnk-a---- 2019/11/30 18:03 1526 WPS 2019.lnk-a---- 2020/7/14 18:52 1064 百度网盘.lnkPS C:\Users\Administrator\Desktop> mkdir ./ming 目录: C:\Users\Administrator\DesktopMode LastWriteTime Length Name---- ------------- ------ ----d----- 2020/7/16 14:19 mingPS C:\Users\Administrator\Desktop> ls 目录: C:\Users\Administrator\DesktopMode LastWriteTime Length Name---- ------------- ------ ----d----- 2020/7/14 17:08 insurv-mina-node-apid----- 2020/7/14 17:45 koad----- 2020/7/16 14:19 mingd----- 2020/7/14 17:55 untitledd----- 2020/7/16 14:16 untitled3-a---- 2020/7/16 12:04 5782870 Navicat Premium 15.x最新注册机.zip-a---- 2020/7/14 17:07 1428 Visual Studio Code.lnk-a---- 2019/11/30 18:03 1526 WPS 2019.lnk-a---- 2020/7/14 18:52 1064 百度网盘.lnkPS C:\Users\Administrator\Desktop> cd ./mingPS C:\Users\Administrator\Desktop\ming> lsPS C:\Users\Administrator\Desktop\ming> koa koa_demo create : koa_demo create : koa_demo/package.json create : koa_demo/app.js create : koa_demo/public create : koa_demo/routes create : koa_demo/routes/index.js create : koa_demo/routes/users.js create : koa_demo/public/javascripts create : koa_demo/views create : koa_demo/views/index.jade create : koa_demo/views/layout.jade create : koa_demo/views/error.jade create : koa_demo/public/images create : koa_demo/public/stylesheets create : koa_demo/public/stylesheets/style.css create : koa_demo/bin create : koa_demo/bin/www install dependencies: > cd koa_demo && npm install run the app: > SET DEBUG=koa_demo:* & npm startPS C:\Users\Administrator\Desktop\ming> ls 目录: C:\Users\Administrator\Desktop\mingMode LastWriteTime Length Name---- ------------- ------ ----d----- 2020/7/16 14:19 koa_demoPS C:\Users\Administrator\Desktop\ming> cd ./koa_demoPS C:\Users\Administrator\Desktop\ming\koa_demo>此时脚手架曾经装置胜利
装置依赖
PS C:\Users\Administrator\Desktop\ming\koa_demo> npm installnpm WARN deprecated chokidar@2.1.8: Chokidar 2 will break on node v14+. Upgrade to chokidar 3 with 15x less dependencies.npm WARN deprecated swig@1.4.2: This package is no longer maintainednpm WARN deprecated jade@1.11.0: Jade has been renamed to pug, please install the latest version of pug instead of jadenpm WARN deprecated constantinople@3.0.2: Please update to at least constantinople 3.1.1npm WARN deprecated transformers@2.1.0: Deprecated, use jstransformernpm WARN deprecated native-or-bluebird@1.2.0: 'native-or-bluebird' is deprecated. Please use 'any-promise' instead.> nodemon@1.19.4 postinstall C:\Users\Administrator\Desktop\ming\koa_demo\node_modules\nodemon> node bin/postinstall || exit 0npm notice created a lockfile as package-lock.json. You should commit this file.npm WARN optional SKIPPING OPTIONAL DEPENDENCY: fsevents@1.2.13 (node_modules\fsevents):npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for fsevents@1.2.13: wanted {"os":"darwin","arch":"any"} (current: {"os":"win32","arch":"x64"})added 367 packages from 208 contributors in 21.748s1 package is looking for funding run `npm fund` for detailsPS C:\Users\Administrator\Desktop\ming\koa_demo>启动我的项目
npm start