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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nofollow" target="_blank" href="https://github.com/mzabriskie/axios">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:

rush:bash;"> $ npm install axios

bower:

rush:bash;"> $ bower install axios

Using cdn:

rush:xhtml;">

基本使用方法

GET请求

rush:js;"> // 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

rush:js;"> 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

rush:js;"> 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)

rush:js;"> axios({ method: 'post',url: '/user/12345',data: { firstName: 'Fred',lastName: 'Flintstone' } });

axios(url,[config])

rush:js;"> // 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[,config]])
  • axios.patch(url[,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])

rush:js;"> 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[,config]])
  • axios#put(url[,config]])
  • axios#patch(url[,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没有指定方法认为GET。

// 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',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).
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&param2=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,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

rush:plain;"> { // `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方法获取,具体使用方法如下:

rush:plain;"> 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,谢谢大家对编程之家的支持

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