Vue进阶（三）：Axios使用详解
介绍
Axios 是一个基于 promise 的 HTTP 库，可以用在浏览器和 node.js 中。
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；
- 浏览器支持；
安装
使用 bower:
$ bower install axios
使用 npm:
$ npm install axios
示例
发送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 (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 POST 请求
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
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
}));
可以通过给 axios传递对应的参数来定制请求：
axios(config)
// Send a POST request
axios({
method: 'post',
url: '/user/12345',
data: {
firstName: 'Fred',
lastName: 'Flintstone'
}
});
axios(url[, config])
// 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])
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。
{
// `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：
{
// `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：
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
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
// 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.
// 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
添加拦截器
你可以在处理 then 或 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 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
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：
var instance = axios.create();
instance.interceptors.request.use(function () {/*...*/});
错误处理
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
/// <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.
