【Vue】5.vue mock数据（模拟后台）

vue实现ajax获取后台数据是通过vue-resource，首先通过npm安装vue-resource

npm install vue-resource --save

安装完成以后，把vue-resource引入到main.js文件中

src/main.js

// The Vue build version to load with the `import` command
// (runtime-only or standalone) has been set in webpack.base.conf with an alias.
import Vue from 'vue'
import App from './App'
import router from './router'
import VueResource from 'vue-resource'
import Layout from './components/layout'

Vue.use(VueResource);
/* eslint-disable no-new */
new Vue({
  el: '#app',
  router,
  template: '',
  components: { Layout }
})

把vue-resource引入项目以后，就可以在任何组件里面直接用了

上面这个就是用vue-resource来进行数据请求的大体流程，作为前端，在开发的过程，遇到这种调用后端接口调试起来还是很麻烦的，我们要找后端的一个服务器，然后关联起来 ，或者把前端代码放上去，这样都是挺麻烦的，解决的办法就是前端放mock data，主要有两种方式：

（1）json-server模拟数据

使用json-server这个工具，可以虚构出后端接口对应的数据，然后在项目里发送特定的请求，就可以发请求拿到模拟的数据，首先npm安装

npm install json-server --save

然后在build/webpack.dev.conf.js中进行配置，参考 json-server

'use strict'
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../config')
const merge = require('webpack-merge')
const baseWebpackConfig = require('./webpack.base.conf')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin')
const portfinder = require('portfinder')

const devWebpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap, usePostCSS: true })
  },
  // cheap-module-eval-source-map is faster for development
  devtool: config.dev.devtool,

  // these devServer options should be customized in /config/index.js
  devServer: {
    clientLogLevel: 'warning',
    historyApiFallback: true,
    hot: true,
    host: process.env.HOST || config.dev.host,
    port: process.env.PORT || config.dev.port,
    open: config.dev.autoOpenBrowser,
    overlay: config.dev.errorOverlay ? {
      warnings: false,
      errors: true,
    } : false,
    publicPath: config.dev.assetsPublicPath,
    proxy: config.dev.proxyTable,
    quiet: true, // necessary for FriendlyErrorsPlugin
    watchOptions: {
      poll: config.dev.poll,
    }
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env': require('../config/dev.env')
    }),
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NamedModulesPlugin(), // HMR shows correct file names in console on update.
    new webpack.NoEmitOnErrorsPlugin(),
    // https://github.com/ampedandwired/html-webpack-plugin
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'index.html',
      inject: true
    }),
  ]
})
//这里是json-server配置信息
// json-server.js
const jsonServer = require('json-server')
const apiServer = jsonServer.create()
const apiRouter = jsonServer.router('db.json') //数据关联server，db.json与index.html同级
const middlewares = jsonServer.defaults()

apiServer.use(middlewares)
apiServer.use('/api',apiRouter)
apiServer.listen(3000, () => {                 //监听端口
  console.log('JSON Server is running')
})

module.exports = new Promise((resolve, reject) => {
  portfinder.basePort = process.env.PORT || config.dev.port
  portfinder.getPort((err, port) => {
    if (err) {
      reject(err)
    } else {
      // publish the new Port, necessary for e2e tests
      process.env.PORT = port
      // add port to devServer config
      devWebpackConfig.devServer.port = port

      // Add FriendlyErrorsPlugin
      devWebpackConfig.plugins.push(new FriendlyErrorsPlugin({
        compilationSuccessInfo: {
          messages: [`Your application is running here: http://${config.dev.host}:${port}`],
        },
        onErrors: config.dev.notifyOnErrors
        ? utils.createNotifierCallback()
        : undefined
      }))

      resolve(devWebpackConfig)
    }
  })
})

配置完成以后，npm run dev 启动，浏览器输入localhost:3000，出现如下图，说明配置成功

那么现在还有一个问题，我们代码的服务端接口是8080，json-server的服务端端口是3000，由于浏览器的同源策略问题，这样请求会存在一个跨域问题，所以这里要做一个服务端代理的配置，配置build/index.js中的proxyTable:

    host: 'localhost', // can be overwritten by process.env.HOST
    port: 8080, // can be overwritten by process.env.HOST, if port is in use, a free one will be determined
    autoOpenBrowser: false,
    errorOverlay: true,
    notifyOnErrors: true,
    poll: false, // https://webpack.js.org/configuration/dev-server/#devserver-watchoptions-
    proxyTable:{
      '/api/':'http://localhost:3000/'
    },

这样就可以在localhost:8080下访问接口了

（2）express启动数据服务

在实际开发中，发现json-server只能用于get请求，不能进行post请求，在网上找的另外一种方法，express既能用于get请求，又能用于post请求，下面说一下express启动服务的配置方法：

'use strict'
const utils = require('./utils')
const webpack = require('webpack')
var express = require('express')
const config = require('../config')
const merge = require('webpack-merge')
const baseWebpackConfig = require('./webpack.base.conf')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin')
const portfinder = require('portfinder')

const devWebpackConfig = merge(baseWebpackConfig, {
  module: {
    rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap, usePostCSS: true })
  },
  // cheap-module-eval-source-map is faster for development
  devtool: config.dev.devtool,

  // these devServer options should be customized in /config/index.js
  devServer: {
    clientLogLevel: 'warning',
    historyApiFallback: true,
    hot: true,
    host: process.env.HOST || config.dev.host,
    port: process.env.PORT || config.dev.port,
    open: config.dev.autoOpenBrowser,
    overlay: config.dev.errorOverlay ? {
      warnings: false,
      errors: true,
    } : false,
    publicPath: config.dev.assetsPublicPath,
    proxy: config.dev.proxyTable,
    quiet: true, // necessary for FriendlyErrorsPlugin
    watchOptions: {
      poll: config.dev.poll,
    }
  },
  plugins: [
    new webpack.DefinePlugin({
      'process.env': require('../config/dev.env')
    }),
    new webpack.HotModuleReplacementPlugin(),
    new webpack.NamedModulesPlugin(), // HMR shows correct file names in console on update.
    new webpack.NoEmitOnErrorsPlugin(),
    // https://github.com/ampedandwired/html-webpack-plugin
    new HtmlWebpackPlugin({
      filename: 'index.html',
      template: 'index.html',
      inject: true
    }),
  ]
})

// json-server.js
//const jsonServer = require('json-server')
//const apiServer = jsonServer.create()
//const apiRouter = jsonServer.router('db.json')
//const middlewares = jsonServer.defaults()
//
//apiServer.use(middlewares)
//apiServer.use('/api',apiRouter)
//apiServer.listen(3000, () => {
//  console.log('JSON Server is running')
//})
//express 配置server
var apiServer = express()
var bodyParser = require('body-parser')
apiServer.use(bodyParser.urlencoded({ extended: true }))
apiServer.use(bodyParser.json())
var apiRouter = express.Router()
var fs = require('fs')
apiRouter.route('/:apiName') //接口路径
  .all(function (req, res) {
    fs.readFile('./db.json', 'utf8', function (err, data) {  //读取接口文件
      if (err) throw err
      var data = JSON.parse(data)
      if (data[req.params.apiName]) {
        res.json(data[req.params.apiName])
      }
      else {
        res.send('no such api name')
      }

    })
  })


apiServer.use('/api', apiRouter);
apiServer.listen(3000, function (err) {
  if (err) {
    console.log(err)
    return
  }
  console.log('Listening at http://localhost:' + 3000 + '\n')
})

module.exports = new Promise((resolve, reject) => {
  portfinder.basePort = process.env.PORT || config.dev.port
  portfinder.getPort((err, port) => {
    if (err) {
      reject(err)
    } else {
      // publish the new Port, necessary for e2e tests
      process.env.PORT = port
      // add port to devServer config
      devWebpackConfig.devServer.port = port

      // Add FriendlyErrorsPlugin
      devWebpackConfig.plugins.push(new FriendlyErrorsPlugin({
        compilationSuccessInfo: {
          messages: [`Your application is running here: http://${config.dev.host}:${port}`],
        },
        onErrors: config.dev.notifyOnErrors
        ? utils.createNotifierCallback()
        : undefined
      }))

      resolve(devWebpackConfig)
    }
  })
})

在浏览器中输入接口地址，如下：