Vue.js教程之axios与网络传输的学习实践
前言
在学习了之前的路由vue-router和状态管理vuex之后,就应该是网络交互了。就学习尤大推荐的axios了。刚好本人对网络请求这块除了会get、put、post和delete这四个方法之外知之甚少,刚好补全上。
注意:Vue官方推荐的网络通信库不再是vue-resource了,推荐使用axios。
为何放弃vue-resource?
尤大的原话:
最近团队讨论了一下,Ajax 本身跟 Vue 并没有什么需要特别整合的地方,使用 fetch polyfill 或是 axios、superagent 等等都可以起到同等的效果,vue-resource 提供的价值和其维护成本相比并不划算,所以决定在不久以后取消对 vue-resource 的官方推荐。已有的用户可以继续使用,但以后不再把 vue-resource 作为官方的 ajax 方案。
axios安装
npm:
$ npm install axios
bower:
$ bower install axios
Using cdn:
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
基本使用方法
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); });
POST请求
axios.post('/user', { firstName: 'Fred', lastName: 'Flintstone' }) .then(function (response) { console.log(response); }) .catch(function (error) { console.log(error); });
同时执行多个请求
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 }));
其实和其他的ajax库一样,基本用法都是差不多的。大家一看就知道怎么用。
axios API
可以直接通过config来完成请求
axios(config)
axios({ method: 'post', url: '/user/12345', data: { firstName: 'Fred', lastName: 'Flintstone' } });
axios(url, [config])
// Send a GET request (default method) axios('/user/12345');
请求方法别名
下面是axios支持的所有请求方法别名,便于各种请求。
注: [...]中的数据表示可以为空。url是ajax请求地址;data是提交的数据对象;config是配置对象,所有ajax配置都可以在config中实现。
- 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]])
并发性
下列接口用于处理并发请求(同时处理多个多个request)
- axios.all(iterable)
- axios.spread(callback)
axios实例
可以用自定义的config创建一个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
下面是实例的所有可用方法,方法中的config会与axios实例中的config合并。(实例可以将一些通用的config先配置好)
- 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]])
Config
重点来了,来看看Config。
下面列出了config的所有配置项,其中之后url是必填的。当method没有指定方法,默认为GET。
{ // `url` is the server URL that will be used for the request // 用来向服务器发送请求的url url: '/user', // `method` is the request method to be used when making the request // 请求方法 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. // 假如`url`不是绝对路径,那么向服务器发送请求的URL将是`baseURL + url` 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, an ArrayBuffer, or a Stream 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 // Must be a plain object or a URLSearchParams object 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 of one of the following types: // - string, plain object, ArrayBuffer, ArrayBufferView, URLSearchParams // - Browser only: FormData, File, Blob // - Node only: Stream 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. // Return a promise and supply a valid response (see [response docs](#response-api)). 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' }, // `responseType` indicates the type of data that the server will respond with // options are 'arraybuffer', 'blob', 'document', 'json', 'text', 'stream' 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 // `onUploadProgress` allows handling of progress events for uploads onUploadProgress: function (progressEvent) { // Do whatever you want with the native progress event }, // `onDownloadProgress` allows handling of progress events for downloads onDownloadProgress: function (progressEvent) { // Do whatever you want with the native progress event }, // `maxContentLength` defines the max size of the http response content allowed maxContentLength: 2000, // `validateStatus` defines whether to resolve or reject the promise for a given // HTTP response status code. If `validateStatus` returns `true` (or is set to `null` // or `undefined`), the promise will be resolved; otherwise, the promise will be // rejected. validateStatus: 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. 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 to configure options 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 // `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`. 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) cancelToken: new CancelToken(function (cancel) { }) }
分析Config
配置参数很多,我们一个一个来了解它们
- url —— 用来向服务器发送请求的url
- method —— 请求方法,默认是GET方法
- baseURL —— 基础URL路径,假如url不是绝对路径,如https://some-domain.com/api/v1/login?name=jack,那么向服务器发送请求的URL将会是baseURL + url。
- transformRequest —— transformRequest方法允许在请求发送到服务器之前修改该请求,此方法只适用于PUT、POST和PATCH方法中。而且,此方法最后必须返回一个string、ArrayBuffer或者Stream。
- transformResponse —— transformResponse方法允许在数据传递到then/catch之前修改response数据。此方法最后也要返回数据。
- headers —— 发送自定义Headers头文件,头文件中包含了http请求的各种信息。
- params —— params是发送请求的查询参数对象,对象中的数据会被拼接成url?param1=value1¶m2=value2。
- paramsSerializer —— params参数序列化器。
- data —— data是在发送POST、PUT或者PATCH请求的数据对象。
- timeout —— 请求超时设置,单位为毫秒
- withCredentials —— 表明是否有跨域请求需要用到证书
- adapter —— adapter允许用户处理更易于测试的请求。返回一个Promise和一个有效的response
- auth —— auth表明提供凭证用于完成http的身份验证。这将会在headers中设置一个Authorization授权信息。自定义Authorization授权要设置在headers中。
- responseType —— 表示服务器将返回响应的数据类型,有arraybuffer、blob、document、json、text、stream这6个类型,默认是json类似数据。
- xsrfCookieName —— 用作 xsrf token 值的 cookie 名称
- xsrfHeaderName —— 带有 xsrf token 值 http head 名称
- onUploadProgress —— 允许在上传过程中的做一些操作
- onDownloadProgress —— 允许在下载过程中的做一些操作
- maxContentLength —— 定义了接收到的response响应数据的最大长度。
- validateStatus —— validateStatus定义了根据HTTP响应状态码决定是否接收或拒绝获取到的promise。如果 validateStatus 返回 true (或设置为 null 或 undefined ),promise将被接收;否则,promise将被拒绝。
- maxRedirects —— maxRedirects定义了在node.js中redirect的最大值,如果设置为0,则没有redirect。
- httpAgent —— 定义在使用http请求时的代理
- httpsAgent —— 定义在使用https请求时的代理
- proxy —— proxy定义代理服务器的主机名和端口,auth
- cancelToken —— cancelToken定义一个 cancel token 用于取消请求
Response
当我们ajax获取数据成功后会返回一个response对象,它包含了以下内容:
{ // `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: {} }
response是通过promise的then方法来获取,具体使用方法如下:
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); });
相对的,我们有时也会出现ajax报错,此时就会到我们的catch中去捕获异常error对象。
总结
以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作能带来一定的帮助,如果有疑问大家可以留言交流,谢谢大家对我们的支持。