// 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);

  });

axios.post('/user', {

    firstName: 'Fred',

    lastName: 'Flintstone'

  })

  .then(function (response) {

    console.log(response);

  })

  .catch(function (error) {

    console.log(error);

  });

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

  }));

// 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'))

});

// 发起一个GET请求（GET是默认的请求方法）

axios('/user/12345');

// `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headers

  transformRequest: [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catch

  transformResponse: [function (data) {

    // 可以对data做任何操作

    return data;

  }],

  // `headers` are custom headers to be sent

  headers: {'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, Buffer

  data: {

    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 token

  xsrfCookieName: 'XSRF-TOKEN', // default

  // `xsrfHeaderName` is the name of the http header that carries the xsrf token value

  xsrfHeaderName: '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.

  // 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) {

  })

}

{

  // 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: {}

}

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);

  });

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';

// 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;

// 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

});

// 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);

  });

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

axios.interceptors.request.eject(myInterceptor);

var instance = axios.create();

instance.interceptors.request.use(function () {/*...*/});

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);

  });

axios.get('/user/12345', {

  validateStatus: function (status) {

    return status < 500; // Reject only if the status code is greater than or equal to 500

  }

})

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.');

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 parameter

    cancel = c;

  })

});

// cancel the request

cancel();

var params = new URLSearchParams();

params.append('param1', 'value1');

params.append('param2', 'value2');

axios.post('/foo', params);