axios中文文档整理

原文地址：https://4m.cn/y6u3y
学习地址：https://www.w3cschool.cn/jquti/jquti-kb3a35x1.html

axios

axios 是一个基于Promise 用于浏览器和 nodejs 的 HTTP 客户端，本质上也是对原生XHR的封装，只不过它是Promise的实现版本，符合最新的ES规范
有以下特点：

从浏览器中创建 XMLHttpRequests
从 node.js 创建 http 请求
支持 Promise API
拦截请求和响应
转换请求数据和响应数据
取消请求
自动转换 JSON 数据
客户端支持防御 XSRF

安装
npm安装

$ npm install axios

bower安装

$ bower install axios

通过cdn引入

<script src="https://unpkg.com/axios/dist/axios.min.js"></script>

例子

发起一个GET请求

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

发起一个POST请求

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

同时发起多个请求

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

可以通过导入相关配置发起请求

axios(config)

// 发起一个POST请求
axios({method: 'post',url: '/user/12345',data: {firstName: 'Fred',lastName: 'Flintstone'}
});

// 获取远程图片
axios({method:'get',url:'http://bit.ly/2mTM3nY',responseType:'stream'
}).then(function(response) {response.data.pipe(fs.createWriteStream('ada_lovelace.jpg'))
});

axios(url[, config])

// 发起一个GET请求（GET是默认的请求方法）
axios('/user/12345');

请求方法别名

为了方便我们为所有支持的请求方法均提供了别名。

axios.request(config)

axios.get(url[, config])

axios.delete(url[, config])

axios.head(url[, config])

axios.options(url[, config])

axios.post(url[, data[, config]])

axios.put(url[, data[, config]])

axios.patch(url[, data[, config]])

注释

当使用以上别名方法时，url，method和data等属性不用在config重复声明。

同时发生的请求

一下两个用来处理同时发生多个请求的辅助函数

axios.all(iterable)

axios.spread(callback)

创建一个实例

你可以创建一个拥有通用配置的axios实例

axios.creat([config])

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

实例的方法

以下是所有可用的实例方法，额外声明的配置将与实例配置合并

axios#request(config)

axios#get(url[, config])

axios#delete(url[, config])

axios#head(url[, config])

axios#options(url[, config])

axios#post(url[, data[, config]])

axios#put(url[, data[, config]])

axios#patch(url[, data[, config]])

请求配置

下面是所有可用的请求配置项，只有url是必填，默认的请求方法是GET，如果没有指定请求方法的话。

{// `url` 是请求的接口地址url: '/user',// `method` 是请求的方法method: 'get', // 默认值// 如果url不是绝对路径，那么会将baseURL和url拼接作为请求的接口地址// 用来区分不同环境，建议使用baseURL: 'https://some-domain.com/api/',// 用于请求之前对请求数据进行操作// 只用当请求方法为‘PUT’，‘POST’和‘PATCH’时可用// 最后一个函数需return出相应数据// 可以修改headerstransformRequest: [function (data, headers) {// 可以对data做任何操作return data;}],// 用于对相应数据进行处理// 它会通过then或者catchtransformResponse: [function (data) {// 可以对data做任何操作return data;}],// `headers` are custom headers to be sentheaders: {'X-Requested-With': 'XMLHttpRequest'},// URL参数// 必须是一个纯对象或者 URL参数对象params: {ID: 12345},// 是一个可选的函数负责序列化`params`// (e.g. https://www.npmjs.com/package/qs, http://api.jquery.com/jquery.param/)paramsSerializer: function(params) {return Qs.stringify(params, {arrayFormat: 'brackets'})},// 请求体数据// 只有当请求方法为'PUT', 'POST',和'PATCH'时可用// 当没有设置`transformRequest`时，必须是以下几种格式// - string, plain object, ArrayBuffer, ArrayBufferView, URLSearchParams// - Browser only: FormData, File, Blob// - Node only: Stream, Bufferdata: {firstName: 'Fred'},// 请求超时时间（毫秒）timeout: 1000,// 是否携带cookie信息withCredentials: false, // default// 统一处理request让测试更加容易// 返回一个promise并提供一个可用的response// 其实我并不知道这个是干嘛的！！！！// (see lib/adapters/README.md).adapter: function (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'},// 响应格式// 可选项 'arraybuffer', 'blob', 'document', 'json', 'text', 'stream'responseType: 'json', // 默认值是json// `xsrfCookieName` is the name of the cookie to use as a value for xsrf tokenxsrfCookieName: 'XSRF-TOKEN', // default// `xsrfHeaderName` is the name of the http header that carries the xsrf token valuexsrfHeaderName: 'X-XSRF-TOKEN', // default// 处理上传进度事件onUploadProgress: function (progressEvent) {// Do whatever you want with the native progress event},// 处理下载进度事件onDownloadProgress: function (progressEvent) {// Do whatever you want with the native progress event},// 设置http响应内容的最大长度maxContentLength: 2000,// 定义可获得的http响应状态码// return true、设置为null或者undefined，promise将resolved,否则将rejectedvalidateStatus: function (status) {return status >= 200 && status < 300; // default},// `maxRedirects` defines the maximum number of redirects to follow in node.js.// If set to 0, no redirects will be followed.// 最大重定向次数？没用过不清楚maxRedirects: 5, // default// `httpAgent` and `httpsAgent` define a custom agent to be used when performing http// and https requests, respectively, in node.js. This allows options to be added like// `keepAlive` that are not enabled by default.httpAgent: new http.Agent({ keepAlive: true }),httpsAgent: new https.Agent({ keepAlive: true }),// 'proxy' defines the hostname and port of the proxy server// Use `false` to disable proxies, ignoring environment variables.// `auth` indicates that HTTP Basic auth should be used to connect to the proxy, and// supplies credentials.// This will set an `Proxy-Authorization` header, overwriting any existing// `Proxy-Authorization` custom headers you have set using `headers`.// 代理proxy: {host: '127.0.0.1',port: 9000,auth: {username: 'mikeymike',password: 'rapunz3l'}},// `cancelToken` specifies a cancel token that can be used to cancel the request// (see Cancellation section below for details)// 用于取消请求？又是一个不知道怎么用的配置项cancelToken: new CancelToken(function (cancel) {})
}

响应组成

response由以下几部分信息组成

{// 服务端返回的数据data: {},// 服务端返回的状态码status: 200,// 服务端返回的状态信息statusText: 'OK',// 响应头// 所有的响应头名称都是小写headers: {},// axios请求配置config: {},// 请求request: {}
}

用then接收以下响应信息

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

全局修改axios默认配置

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';

实例默认配置

// 创建实例时修改配置
var instance = axios.create({baseURL: 'https://api.example.com'
});// 实例创建之后修改配置
instance.defaults.headers.common['Authorization'] = AUTH_TOKEN;

配置优先级

配置项通过一定的规则合并，request config > instance.defaults > 系统默认，优先级高的覆盖优先级低的。

// 创建一个实例，这时的超时时间为系统默认的 0
var instance = axios.create();// 通过instance.defaults重新设置超时时间为2.5s，因为优先级比系统默认高
instance.defaults.timeout = 2500;// 通过request config重新设置超时时间为5s，因为优先级比instance.defaults和系统默认都高
instance.get('/longRequest', {timeout: 5000
});

拦截器

你可以在then和catch之前拦截请求和响应。

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

如果之后想移除拦截器你可以这么做

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

你也可以为axios实例添加一个拦截器

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

错误处理

axios.get('/user/12345').catch(function (error) {if (error.response) {// 发送请求后，服务端返回的响应码不是 2xx   console.log(error.response.data);console.log(error.response.status);console.log(error.response.headers);} else if (error.request) {// 发送请求但是没有响应返回console.log(error.request);} else {// 其他错误console.log('Error', error.message);}console.log(error.config);});

你可以用validateStatus定义一个http状态码返回的范围.

axios.get('/user/12345', {validateStatus: function (status) {return status < 500; // Reject only if the status code is greater than or equal to 500}
})

取消请求

你可以通过cancel token来取消一个请求

The axios cancel token API is based on the withdrawn cancelable promises proposal.

You can create a cancel token using the CancelToken.source factory as shown below:

var CancelToken = axios.CancelToken;
var source = CancelToken.source();axios.get('/user/12345', {cancelToken: source.token
}).catch(function(thrown) {if (axios.isCancel(thrown)) {console.log('Request canceled', thrown.message);} else {// handle error}
});// cancel the request (the message parameter is optional)
source.cancel('Operation canceled by the user.');

You can also create a cancel token by passing an executor function to the CancelToken constructor:

var CancelToken = axios.CancelToken;
var cancel;axios.get('/user/12345', {cancelToken: new CancelToken(function executor(c) {// An executor function receives a cancel function as a parametercancel = c;})
});// cancel the request
cancel();

Note: you can cancel several requests with the same cancel token.

Using application/x-www-form-urlencoded format

By default, axios serializes JavaScript objects to JSON. To send data in the application/x-www-form-urlencoded format instead, you can use one of the following options.

Browser

In a browser, you can use the URLSearchParams API as follows:

var params = new URLSearchParams();
params.append('param1', 'value1');
params.append('param2', 'value2');
axios.post('/foo', params);

Note that URLSearchParams is not supported by all browsers (see caniuse.com), but there is a polyfill available (make sure to polyfill the global environment).

Alternatively, you can encode data using the qs library:

var qs = require('qs');
axios.post('/foo', qs.stringify({ 'bar': 123 }));

Node.js

In node.js, you can use the querystring module as follows:

var querystring = require('querystring');
axios.post('http://something.com/', querystring.stringify({ foo: 'bar' }));

You can also use the qs library.

Semver

Until axios reaches a 1.0 release, breaking changes will be released with a new minor version. For example 0.5.1, and 0.5.4 will have the same API, but 0.6.0 will have breaking changes.

Promises

axios depends on a native ES6 Promise implementation to be supported.
If your environment doesn’t support ES6 Promises, you can polyfill.

TypeScript

axios includes TypeScript definitions.

import axios from 'axios';
axios.get('/user?ID=12345');