Vue中如何发送ajax请求

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我们如何在vue项目中发送Ajax请求呢?可以借助axios来方便的实现,我们来了解一下。

axios

基于 Promise 的 HTTP 请求客户端,可同时在浏览器和 node.js 中使用

功能特性

  • 在浏览器中发送 XMLHttpRequests 请求
  • 在 node.js 中发送 http请求
  • 支持 Promise API
  • 拦截请求和响应
  • 转换请求和响应数据
  • 自动转换 JSON 数据
  • 客户端支持保护安全免受 XSRF 攻击

安装

使用 bower:

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$ bower install axios

使用 npm:

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$ npm install axios

例子

发送一个 GET 请求

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// Make a request for a user with a given ID
axios.get('/user?ID=12345')
  .then(function (response) {
    console.log(response);
  })
  .catch(function (response) {
    console.log(response);
  });
 
// Optionally the request above could also be done as
axios.get('/user', {
    params: {
      ID: 12345
    }
  })
  .then(function (response) {
    console.log(response);
  })
  .catch(function (response) {
    console.log(response);
  });

发送一个 POST 请求

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axios.post('/user', {
    firstName: 'Fred',
    lastName: 'Flintstone'
  })
  .then(function (response) {
    console.log(response);
  })
  .catch(function (response) {
    console.log(response);
  });

发送多个并发请求

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function getUserAccount() {
  return axios.get('/user/12345');
}
 
function getUserPermissions() {
  return axios.get('/user/12345/permissions');
}
 
axios.all([getUserAccount(), getUserPermissions()])
  .then(axios.spread(function (acct, perms) {
    // Both requests are now complete
  }));

axios API

可以通过给 axios传递对应的参数来定制请求:

axios(config)
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// Send a POST request
axios({
  method: 'post',
  url: '/user/12345',
  data: {
    firstName: 'Fred',
    lastName: 'Flintstone'
  }
});
axios(url[, config])
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// Sned a GET request (default method)
axios('/user/12345');

请求方法别名

为方便起见,我们为所有支持的请求方法都提供了别名

axios.get(url[, config])
axios.delete(url[, config])
axios.head(url[, config])
axios.post(url[, data[, config]])
axios.put(url[, data[, config]])
axios.patch(url[, data[, config]])
注意

当使用别名方法时, url、 method 和 data 属性不需要在 config 参数里面指定。

并发

处理并发请求的帮助方法

axios.all(iterable)
axios.spread(callback)

创建一个实例

你可以用自定义配置创建一个新的 axios 实例。

axios.create([config])
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var instance = axios.create({
  baseURL: 'https://some-domain.com/api/',
  timeout: 1000,
  headers: {'X-Custom-Header': 'foobar'}
});

实例方法

所有可用的实例方法都列在下面了,指定的配置将会和该实例的配置合并。

axios#request(config)
axios#get(url[, config])
axios#delete(url[, config])
axios#head(url[, config])
axios#post(url[, data[, config]])
axios#put(url[, data[, config]])
axios#patch(url[, data[, config]])

请求配置

下面是可用的请求配置项,只有 url 是必需的。如果没有指定 method ,默认的请求方法是 GET

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{
  // `url` is the server URL that will be used for the request
  url: '/user',
 
  // `method` is the request method to be used when making the request
  method: 'get', // default
 
  // `baseURL` will be prepended to `url` unless `url` is absolute. 
  // It can be convenient to set `baseURL` for an instance of axios to pass relative URLs 
  // to methods of that instance.
  baseURL: 'https://some-domain.com/api/',
 
  // `transformRequest` allows changes to the request data before it is sent to the server
  // This is only applicable for request methods 'PUT', 'POST', and 'PATCH'
  // The last function in the array must return a string or an ArrayBuffer
  transformRequest: [function (data) {
    // Do whatever you want to transform the data
 
    return data;
  }],
 
  // `transformResponse` allows changes to the response data to be made before
  // it is passed to then/catch
  transformResponse: [function (data) {
    // Do whatever you want to transform the data
 
    return data;
  }],
 
  // `headers` are custom headers to be sent
  headers: {'X-Requested-With': 'XMLHttpRequest'},
 
  // `params` are the URL parameters to be sent with the request
  params: {
    ID: 12345
  },
 
  // `paramsSerializer` is an optional function in charge of serializing `params`
  // (e.g. https://www.npmjs.com/package/qs, http://api.jquery.com/jquery.param/)
  paramsSerializer: function(params) {
    return Qs.stringify(params, {arrayFormat: 'brackets'})
  },
 
  // `data` is the data to be sent as the request body
  // Only applicable for request methods 'PUT', 'POST', and 'PATCH'
  // When no `transformRequest` is set, must be a string, an ArrayBuffer or a hash
  data: {
    firstName: 'Fred'
  },
 
  // `timeout` specifies the number of milliseconds before the request times out.
  // If the request takes longer than `timeout`, the request will be aborted.
  timeout: 1000,
 
  // `withCredentials` indicates whether or not cross-site Access-Control requests
  // should be made using credentials
  withCredentials: false, // default
 
  // `adapter` allows custom handling of requests which makes testing easier.
  // Call `resolve` or `reject` and supply a valid response (see [response docs](#response-api)).
  adapter: function (resolve, reject, config) {
    /* ... */
  },
 
  // `auth` indicates that HTTP Basic auth should be used, and supplies credentials.
  // This will set an `Authorization` header, overwriting any existing
  // `Authorization` custom headers you have set using `headers`.
  auth: {
    username: 'janedoe',
    password: 's00pers3cret'
  }
 
  // `responseType` indicates the type of data that the server will respond with
  // options are 'arraybuffer', 'blob', 'document', 'json', 'text'
  responseType: 'json', // default
 
  // `xsrfCookieName` is the name of the cookie to use as a value for xsrf token
  xsrfCookieName: 'XSRF-TOKEN', // default
 
  // `xsrfHeaderName` is the name of the http header that carries the xsrf token value
  xsrfHeaderName: 'X-XSRF-TOKEN', // default
 
  // `progress` allows handling of progress events for 'POST' and 'PUT uploads'
  // as well as 'GET' downloads
  progress: function(progressEvent) {
    // Do whatever you want with the native progress event
  }
}

响应的数据结构

响应的数据包括下面的信息:

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{
  // `data` is the response that was provided by the server
  data: {},
 
  // `status` is the HTTP status code from the server response
  status: 200,
 
  // `statusText` is the HTTP status message from the server response
  statusText: 'OK',
 
  // `headers` the headers that the server responded with
  headers: {},
 
  // `config` is the config that was provided to `axios` for the request
  config: {}
}

当使用 then 或者 catch 时, 你会收到下面的响应:

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axios.get('/user/12345')
  .then(function(response) {
    console.log(response.data);
    console.log(response.status);
    console.log(response.statusText);
    console.log(response.headers);
    console.log(response.config);
});

默认配置

你可以为每一个请求指定默认配置。

全局 axios 默认配置

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axios.defaults.baseURL = 'https://api.example.com';
axios.defaults.headers.common['Authorization'] = AUTH_TOKEN;
axios.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded';

自定义实例默认配置

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// Set config defaults when creating the instance
var instance = axios.create({
  baseURL: 'https://api.example.com'
});
 
// Alter defaults after instance has been created
instance.defaults.headers.common['Authorization'] = AUTH_TOKEN;

配置的优先顺序

Config will be merged with an order of precedence. The order is library defaults found in lib/defaults.js, then defaults property of the instance, and finally config argument for the request. The latter will take precedence over the former. Here's an example.

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// Create an instance using the config defaults provided by the library
// At this point the timeout config value is `0` as is the default for the library
var instance = axios.create();
 
// Override timeout default for the library
// Now all requests will wait 2.5 seconds before timing out
instance.defaults.timeout = 2500;
 
// Override timeout for this request as it's known to take a long time
instance.get('/longRequest', {
  timeout: 5000
});

拦截器

你可以在处理 then 或 catch 之前拦截请求和响应

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// 添加一个请求拦截器
axios.interceptors.request.use(function (config) {
    // Do something before request is sent
    return config;
  }, function (error) {
    // Do something with request error
    return Promise.reject(error);
  });
 
// 添加一个响应拦截器
axios.interceptors.response.use(function (response) {
    // Do something with response data
    return response;
  }, function (error) {
    // Do something with response error
    return Promise.reject(error);
  });

移除一个拦截器:

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var myInterceptor = axios.interceptors.request.use(function () {/*...*/});
axios.interceptors.request.eject(myInterceptor);

你可以给一个自定义的 axios 实例添加拦截器:

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var instance = axios.create();
instance.interceptors.request.use(function () {/*...*/});

错误处理

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axios.get('/user/12345')
  .catch(function (response) {
    if (response instanceof Error) {
      // Something happened in setting up the request that triggered an Error
      console.log('Error', response.message);
    } else {
      // The request was made, but the server responded with a status code
      // that falls out of the range of 2xx
      console.log(response.data);
      console.log(response.status);
      console.log(response.headers);
      console.log(response.config);
    }
  });

Promises

axios 依赖一个原生的 ES6 Promise 实现,如果你的浏览器环境不支持 ES6 Promises,你需要引入 polyfill

TypeScript

axios 包含一个 TypeScript 定义

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/// <reference path="axios.d.ts" />
import * as axios from 'axios';
axios.get('/user?ID=12345');

Credits

axios is heavily inspired by the $http service provided in Angular. Ultimately axios is an effort to provide a standalone $http-like service for use outside of Angular.

License

MIT

原文链接:https://www.awesomes.cn/repo/axios/axios