Axios summary

A, install,

NPM install axios –save

Bower install axios –save

3, direct use of CDN is introduced into < script SRC = “https://unpkg.com/axios/dist/axios.min.js” > < / script >

Second, the example

1. Send a GET request

// Send the request with the given ID
axios.get('/user? ID=12345')
  .then(function(response){
    console.log(response);
  })
  .catch(function(err){
    console.log(err);
  });
// The above requests can also be sent in this way
axios.get('/user', {params: {ID:12345
  }
})
.then(function(response){
  console.log(response);
})
.catch(function(err){
  console.log(err);
});
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2. Send a POST request

axios.post('/user', {firstName:'Fred'.lastName:'Flintstone'
})
.then(function(res){
  console.log(res);
})
.catch(function(err){
  console.log(err);
});
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3. Multiple requests at a time

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){
    // This function is triggered when both requests are completed, with two arguments representing the result returned
  }))
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The AXIos API

(A) Axios can be configured (`config`) to send the request

1, axios (config)

// Send a POST request
axios({
    method:"POST",
    url:'/user/12345'.data:{
        firstName:"Fred",
        lastName:"Flintstone"}});Copy the code

2, axios ([url, config])

// Send a 'GET' request (default request)
axios('/user/12345');
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(2) Aliases for request methods. Convenient aliases are provided for all supported request methods

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]])
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Note: When we use the alias method,url,method,dataThese parameters do not need to be specified in the configuration

Concurrency. Concurrency is an auxiliary function that helps you handle concurrent requests

// Iterable is an iterable set of parameters
axios.all(iterable)
// Callback will not be executed until all requests are completed
axios.spread(callback)
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(4) create a`axios`Instance, and you can customize its configuration

1, axios. Create (/ config)

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

2. Method of instance

Here is the instance method, noting that the configuration defined will be merged with the configuration of the instance created using create

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]])
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4. Request Config

Here are the configuration options requested, onlyurlThe option is required ifmethodOption is not defined, then it defaults toGETTo make a request

{
  // 'url' is the requested server address
  url:'/user'.// 'method' is the method of requesting the resource
  method:'get'//default
  // If 'url' is not an absolute address, 'baseURL' will be appended to 'url'
  // When 'url' is a relative address, setting 'baseURL' is very convenient
  baseURL:'https://some-domain.com/api/'.// The 'transformRequest' option allows us to make some changes to the requested data before it is sent to the server
  // This option only applies to 'PUT/POST /patch' requests
  // The last function in the array must return a string, - an ArrayBuffer, or a Stream
  transformRequest: [function(data){
    // Change the data here to suit your needs
    returndata; }].// The 'transformResponse' option allows us to make changes to the data before it is sent to the 'then/catch' method
  transformResponse: [function(data){
    // Change the data here to suit your needs
    returndata; }].// The 'headers' option is a custom request header to be sent
  headers: {'X-Requested-With':'XMLHttpRequest'},
  // The 'params' option is the request parameter to be sent with the request ---- is usually linked after the URL
  // Its type must be a pure object or URLSearchParams object
  params: {
    ID:12345
  },
  // 'paramsSerializer' is an optional function that serializes parameters (params)
  / / (https://www.npmjs.com/package/qs, http://api.jquery.com/jquery.param, for example)
  paramsSerializer: function(params){
    return Qs.stringify(params,{arrayFormat:'brackets'})},// The 'data' option is the data to be sent as a request body
  // This option applies only to methods: 'PUT/POST /patch'
  // DADA must be one of the following types when the 'transformRequest' option is not set
  //string/plain/object/ArrayBuffer/ArrayBufferView/URLSearchParams
  // Only browser: FormData/File/Bold
  / / the node only: the Stream
  data {
    firstName:"Fred"
  },
  // The 'timeout' option defines the number of milliseconds the request will be delayed
  // If the request takes longer than the delay, the request is aborted

  timeout:1000.// The 'withCredentails' option indicates whether the request is cross-domain
  
  withCredentials:false.//default
  The adapter option allows you to customize processing requests, which makes testing easier
  // Return a promise and provide a validation return
  adapter: function(config){
    / *... * /
  },
  // 'auth' indicates that HTTP-based authentication should be used and certificates provided
  // This sets an authorization header and overwrites the authorization header you set in the header
  auth: {
    username:"zhangsan".password: "s00sdkf"
  },
  // The format of the returned data
  / / its option is arraybuffer, blob, document, json, text, stream
  responseType:'json'.//default
  //
  xsrfCookieName: 'XSRF-TOKEN'.//default
  xsrfHeaderName:'X-XSRF-TOKEN'.//default
  // 'onUploadProgress' upload progress event
  onUploadProgress:function(progressEvent){
    // Download progress events
onDownloadProgress:function(progressEvent){}},// The maximum value of the corresponding content
  maxContentLength:2000.// 'validateStatus' defines whether to resolve or reject a promise according to the corresponding HTTP status code
  // If 'validateStatus' returns true(or set to' null 'or' undefined '), then the promise state will be Resolved, otherwise it will be rejected
  validateStatus:function(status){
    return status >= 200 && status <300;//default
  },
  // 'maxRedirects' defines the maximum number of redirects in nodejs
  maxRedirects: 5.//default
  // 'httpAgent/httpsAgent' defines the custom proxy to use when sending HTTP/HTTPS requests
  //keeyAlive is not activated by default in the option
  httpAgent: new http.Agent({keeyAlive:true}),
  httpsAgent: new https.Agent({keeyAlive:true}),
  //proxy defines the host name and port number,
  // 'auth' indicates that HTTP basic authentication should be linked to a proxy and provide a certificate
  // This will set a proxy-authorization header and override the existing proxy-authorization header
  proxy: {
    host:'127.0.0.1'.port: 9000.auth: {
      username:'skda'.password:'radsd'}},// 'cancelToken' defines a cancel token used to cancel a request
  // See Cancelation
  cancelToken: new cancelToken(function(cancel){})}Copy the code

Fifth, the content of the request returned

{
  data:{},
  status:200.// HTTP status text returned from the server
  statusText:'OK'.// Response header information
  headers: {},
  // 'config' is some configuration information at the time of request
  config: {}
}
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You can get response information like this

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

You can set the default configuration to work for all requests

1. Global default configuration

axios.defaults.baseURL = 'http://api.exmple.com';
axios.defaults.headers.common['Authorization'] = AUTH_TOKEN;
axios.defaults.headers.post['content-Type'] = 'appliction/x-www-form-urlencoded';
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2. Custom instance default Settings

// Configure the default configuration when creating the instance
var instance = axios.create({
    baseURL: 'https://api.example.com'
});

// Modify the configuration when the instance is created
instance.defaults.headers.common["Authorization"] = AUTH_TOKEN;
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3. The configuration has a priority

The config configuration will be combined in priority order, the default configuration in lib/defauts.js, then the default configuration in the instance, and finally the configuration of the config parameter in the request, as the hierarchy increases, and the latter overrides the previous example.

// The default configuration in the Libray directory is used when creating an instance
// In this case the value of timeout is 0, which comes from the default value of Libray
var instance = axios.create();
// Override the library defaults
// Now all requests are sent after 2.5s
instance.defaults.timeout = 2500;
// The timeout restores the previous 2.5s to 5s
instance.get('/longRequest',{
  timeout: 5000
});
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7. Interceptor

You can request and respond on arrivalthen/catchIntercept them before

// Add a request interceptor
axios.interceptors.request.use(function(config){
  // Do something before the request is issued
  return config;
},function(err){
  //Do something with request error
  return Promise.reject(error);
});
// Add a response interceptor
axios.interceptors.response.use(function(res){
  // This is where the returned data is processed
  return res;
},function(err){
  //Do something with response error
  return Promise.reject(error);
})
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2. Cancel the interceptor

var myInterceptor = axios.interceptor.request.use(function(){/ *... * /});
axios.interceptors.request.eject(myInterceptor);
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3. Add interceptors to custom AXIos instances

var instance = axios.create();
instance.interceptors.request.use(function(){})
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4. Sequence of interceptor execution

axios.interceptors.request.use(function(config) {
    / / send the token
    console.log('axios.interceptors.request - 1');
    return config;
}, function() {}); axios.interceptors.request.use(function(config) {
    console.log('axios.interceptors.request - 2');
    return config;
}, function() {});// axios => function request() => .get .post .delete

axios.interceptors.response.use(function(data) {
    console.log('axios.interceptors.response - 1');
    console.log('data', data);
    return data;
}, function() {}); axios.interceptors.response.use(function(data) {
    console.log('axios.interceptors.response - 2');
    console.log('data', data);
    return data;
}, function() {});/ / execution sequence: axios. Interceptors. Request - 2
// axios.interceptors.request-1
// axios.interceptors.response-1
// axios.interceptors.response-2
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this.interceptors.request.forEach(function unshiftRequestInterceptors(interceptor) {
	chain.unshift(interceptor.fulfilled, interceptor.rejected);
});

this.interceptors.response.forEach(function pushResponseInterceptors(interceptor) {
	chain.push(interceptor.fulfilled, interceptor.rejected);
});
Req2-req1-resp2; req2-req1-resp2; req2-req1-resp2
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Error handling

axios.get('/user/12345')
  .catch(function(error){
    if(error.response){
      // The request has been sent, but the status returned by the server response is outside the range of 2xx
      console.log(error.response.data);
      console.log(error.response.status);
      console.log(error.response.header);
    }else {
      // Some errors are triggered when setting the request
      console.log('Error',error.message);
    }
    console.log(error.config);
  });
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Nine, cancellation,

You can go through onecancel tokenTo cancel a request

You can go throughCancelToken.sourceFactory function to create onecancel token

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 (information parameters can be set)
source.cancel("Operation cancelled by user");
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CancelToken You can 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(c){
    // This executor function takes a cancel function as an argumentcancel = c; })})// Cancel the request
cancel();
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A, install,

Second, the example

The AXIos API

(A) Axios can be configured (config) to send the request

(2) Aliases for request methods. Convenient aliases are provided for all supported request methods

Concurrency. Concurrency is an auxiliary function that helps you handle concurrent requests

(4) create aaxiosInstance, and you can customize its configuration

4. Request Config

Fifth, the content of the request returned

Default configuration

7. Interceptor

Error handling

Nine, cancellation,

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(A) Axios can be configured (`config`) to send the request

(4) create a`axios`Instance, and you can customize its configuration