plc-sim/client/node_modules/axios

Promise based HTTP client for the browser and node.js

Website • Documentation

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Table of Contents

• Features
• Browser Support
• Installing
  • Package manager
  • CDN
• Example
• Axios API
• Request method aliases
• Concurrency 👎
• Creating an instance
• Instance methods
• Request Config
• Response Schema
• Config Defaults
  • Global axios defaults
  • Custom instance defaults
  • Config order of precedence
• Interceptors
  • Multiple Interceptors
• Handling Errors
• Cancellation
  • AbortController
  • CancelToken 👎
• Using application/x-www-form-urlencoded format
  • URLSearchParams
  • Query string
  • 🆕 Automatic serialization
• Using multipart/form-data format
  • FormData
  • 🆕 Automatic serialization
• Files Posting
• HTML Form Posting
• 🆕 Progress capturing
• 🆕 Rate limiting
• Semver
• Promises
• TypeScript
• Resources
• Credits
• License

Features

• Make XMLHttpRequests from the browser
• Make http requests from node.js
• Supports the Promise API
• Intercept request and response
• Transform request and response data
• Cancel requests
• Automatic transforms for JSON data
• 🆕 Automatic data object serialization to multipart/form-data and x-www-form-urlencoded body encodings
• Client side support for protecting against XSRF

Browser Support

Latest ✔	Latest ✔	Latest ✔	Latest ✔	Latest ✔	11 ✔

Installing

Package manager

Using npm:

$ npm install axios

Using bower:

$ bower install axios

Using yarn:

$ yarn add axios

Using pnpm:

$ pnpm add axios

Once the package is installed, you can import the library using import or require approach:

import axios, {isCancel, AxiosError} from 'axios';

You can also use the default export, since the named export is just a re-export from the Axios factory:

import axios from 'axios';

console.log(axios.isCancel('something'));
````

If you use `require` for importing, **only default export is available**:

js const axios = require('axios');

console.log(axios.isCancel('something'));

For cases where something went wrong when trying to import a module into a custom or legacy environment,
you can try importing the module package directly:

js const axios = require('axios/dist/browser/axios.cjs'); // browser commonJS bundle (ES2017) // const axios = require('axios/dist/node/axios.cjs'); // node commonJS bundle (ES2017)

### CDN

Using jsDelivr CDN (ES5 UMD browser module):

html

Using unpkg CDN:

html

## Example

> **Note** CommonJS usage
> In order to gain the TypeScript typings (for intellisense / autocomplete) while using CommonJS imports with `require()`, use the following approach:

js import axios from 'axios'; //const axios = require('axios'); // legacy way

// Make a request for a user with a given ID axios.get('/user?ID=12345') .then(function (response) {

// handle success
console.log(response);

}) .catch(function (error) {

// handle error
console.log(error);

}) .finally(function () {

// always executed

});

// 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);

}) .finally(function () {

// always executed

});

// Want to use async/await? Add the async keyword to your outer function/method. async function getUser() { try {

const response = await axios.get('/user?ID=12345');
console.log(response);

} catch (error) {

console.error(error);

} }

> **Note**: `async/await` is part of ECMAScript 2017 and is not supported in Internet
> Explorer and older browsers, so use with caution.

Performing a `POST` request

js axios.post('/user', {

firstName: 'Fred',
lastName: 'Flintstone'

}) .then(function (response) {

console.log(response);

}) .catch(function (error) {

console.log(error);

});

Performing multiple concurrent requests

js function getUserAccount() { return axios.get('/user/12345'); }

function getUserPermissions() { return axios.get('/user/12345/permissions'); }

Promise.all([getUserAccount(), getUserPermissions()]) .then(function (results) {

const acct = results[0];
const perm = results[1];

});

## axios API

Requests can be made by passing the relevant config to `axios`.

##### axios(config)

js // Send a POST request axios({ method: 'post', url: '/user/12345', data: {

firstName: 'Fred',
lastName: 'Flintstone'

} });

js // GET request for remote image in node.js axios({ method: 'get', url: 'https://bit.ly/2mTM3nY', responseType: 'stream' }) .then(function (response) {

response.data.pipe(fs.createWriteStream('ada_lovelace.jpg'))

});

##### axios(url[, config])

js // Send a GET request (default method) axios('/user/12345');

### Request method aliases

For convenience, aliases have been provided for all common request methods.

##### axios.request(config)
##### axios.get(url[, config])
##### axios.delete(url[, config])
##### axios.head(url[, config])
##### axios.options(url[, config])
##### axios.post(url[, data[, config]])
##### axios.put(url[, data[, config]])
##### axios.patch(url[, data[, config]])

###### NOTE
When using the alias methods `url`, `method`, and `data` properties don't need to be specified in config.

### Concurrency (Deprecated)
Please use `Promise.all` to replace the below functions.

Helper functions for dealing with concurrent requests.

axios.all(iterable)
axios.spread(callback)

### Creating an instance

You can create a new instance of axios with a custom config.

##### axios.create([config])

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

### Instance methods

The available instance methods are listed below. The specified config will be merged with the instance config.

##### axios#request(config)
##### axios#get(url[, config])
##### axios#delete(url[, config])
##### axios#head(url[, config])
##### axios#options(url[, config])
##### axios#post(url[, data[, config]])
##### axios#put(url[, data[, config]])
##### axios#patch(url[, data[, config]])
##### axios#getUri([config])

## Request Config

These are the available config options for making requests. Only the `url` is required. Requests will default to `GET` if `method` is not specified.

js { // 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', 'PATCH' and 'DELETE' // The last function in the array must return a string or an instance of Buffer, ArrayBuffer, // FormData or Stream // You may modify the headers object. transformRequest: [function (data, headers) {

// 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 config in charge of serializing params paramsSerializer: {

encode?: (param: string): string => { /* Do custom ops here and return transformed string */ }, // custom encoder function; sends Key/Values in an iterative fashion
serialize?: (params: Record<string, any>, options?: ParamsSerializerOptions ), // mimic pre 1.x behavior and send entire params object to a custom serializer func. Allows consumer to control how params are serialized.
indexes: false // array indexes format (null - no brackets, false (default) - empty brackets, true - brackets with indexes)

},

// data is the data to be sent as the request body // Only applicable for request methods 'PUT', 'POST', 'DELETE , 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, Buffer, FormData (form-data package) data: {

firstName: 'Fred'

},

// syntax alternative to send data into the body // method post // only the value is sent, not the key data: 'Country=Brasil&City=Belo Horizonte',

// 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, // default is 0 (no timeout)

// 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 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. // Please note that only HTTP Basic auth is configurable through this parameter. // For Bearer tokens and such, use Authorization custom headers instead. auth: {

username: 'janedoe',
password: 's00pers3cret'

},

// responseType indicates the type of data that the server will respond with // options are: 'arraybuffer', 'document', 'json', 'text', 'stream' // browser only: 'blob' responseType: 'json', // default

// responseEncoding indicates encoding to use for decoding responses (Node.js only) // Note: Ignored for responseType of 'stream' or client-side requests responseEncoding: 'utf8', // 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 // browser & node.js onUploadProgress: function ({loaded, total, progress, bytes, estimated, rate, upload = true}) {

// Do whatever you want with the Axios progress event

},

// onDownloadProgress allows handling of progress events for downloads // browser & node.js onDownloadProgress: function ({loaded, total, progress, bytes, estimated, rate, download = true}) {

// Do whatever you want with the Axios progress event

},

// maxContentLength defines the max size of the http response content in bytes allowed in node.js maxContentLength: 2000,

// maxBodyLength (Node only option) defines the max size of the http request content in bytes allowed maxBodyLength: 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: 21, // default

// beforeRedirect defines a function that will be called before redirect. // Use this to adjust the request options upon redirecting, // to inspect the latest response headers, // or to cancel the request by throwing an error // If maxRedirects is set to 0, beforeRedirect is not used. beforeRedirect: (options, { headers }) => {

if (options.hostname === "example.com") {
  options.auth = "user:password";
}

},

// socketPath defines a UNIX Socket to be used in node.js. // e.g. '/var/run/docker.sock' to send requests to the docker daemon. // Only either socketPath or proxy can be specified. // If both are specified, socketPath is used. socketPath: null, // default

// transport determines the transport method that will be used to make the request. If defined, it will be used. Otherwise, if maxRedirects is 0, the default http or https library will be used, depending on the protocol specified in protocol. Otherwise, the httpFollow or httpsFollow library will be used, again depending on the protocol, which can handle redirects. transport: undefined, // 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, port, and protocol of the proxy server. // You can also define your proxy using the conventional http_proxy and // https_proxy environment variables. If you are using environment variables // for your proxy configuration, you can also define a no_proxy environment // variable as a comma-separated list of domains that should not be proxied. // 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. // If the proxy server uses HTTPS, then you must set the protocol to https. proxy: {

protocol: 'https',
host: '127.0.0.1',
// hostname: '127.0.0.1' // Takes precedence over 'host' if both are defined
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) { }),

// an alternative way to cancel Axios requests using AbortController signal: new AbortController().signal,

// decompress indicates whether or not the response body should be decompressed // automatically. If set to true will also remove the 'content-encoding' header // from the responses objects of all decompressed responses // - Node only (XHR cannot turn off decompression) decompress: true // default

// insecureHTTPParser boolean. // Indicates where to use an insecure HTTP parser that accepts invalid HTTP headers. // This may allow interoperability with non-conformant HTTP implementations. // Using the insecure parser should be avoided. // see options https://nodejs.org/dist/latest-v12.x/docs/api/http.html#http_http_request_url_options_callback // see also https://nodejs.org/en/blog/vulnerability/february-2020-security-releases/#strict-http-header-parsing-none insecureHTTPParser: undefined // default

// transitional options for backward compatibility that may be removed in the newer versions transitional: {

// silent JSON parsing mode
// `true`  - ignore JSON parsing errors and set response.data to null if parsing failed (old behaviour)
// `false` - throw SyntaxError if JSON parsing failed (Note: responseType must be set to 'json')
silentJSONParsing: true, // default value for the current Axios version

// try to parse the response string as JSON even if `responseType` is not 'json'
forcedJSONParsing: true,

// throw ETIMEDOUT error instead of generic ECONNABORTED on request timeouts
clarifyTimeoutError: false,

},

env: {

// The FormData class to be used to automatically serialize the payload into a FormData object
FormData: window?.FormData || global?.FormData

},

formSerializer: {

  visitor: (value, key, path, helpers) => {}; // custom visitor function to serialize form values
  dots: boolean; // use dots instead of brackets format
  metaTokens: boolean; // keep special endings like {} in parameter key
  indexes: boolean; // array indexes format null - no brackets, false - empty brackets, true - brackets with indexes

},

// http adapter only (node.js) maxRate: [

100 * 1024, // 100KB/s upload limit,
100 * 1024  // 100KB/s download limit

] }

## Response Schema

The response for a request contains the following information.

js { // 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 HTTP headers that the server responded with // All header names are lowercase and can be accessed using the bracket notation. // Example: response.headers['content-type'] headers: {},

// config is the config that was provided to axios for the request config: {},

// request is the request that generated this response // It is the last ClientRequest instance in node.js (in redirects) // and an XMLHttpRequest instance in the browser request: {} }

When using `then`, you will receive the response as follows:

js 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);

});

When using `catch`, or passing a [rejection callback](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/then) as second parameter of `then`, the response will be available through the `error` object as explained in the [Handling Errors](#handling-errors) section.

## Config Defaults

You can specify config defaults that will be applied to every request.

### Global axios defaults

js axios.defaults.baseURL = 'https://api.example.com';

// Important: If axios is used with multiple domains, the AUTH_TOKEN will be sent to all of them. // See below for an example using Custom instance defaults instead. axios.defaults.headers.common['Authorization'] = AUTH_TOKEN;

axios.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded';

### Custom instance defaults

js // Set config defaults when creating the instance const instance = axios.create({ baseURL: 'https://api.example.com' });

// Alter defaults after instance has been created instance.defaults.headers.common['Authorization'] = AUTH_TOKEN;

### Config order of precedence

Config will be merged with an order of precedence. The order is library defaults found in [lib/defaults.js](https://github.com/axios/axios/blob/master/lib/defaults/index.js#L28), 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.

js // 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 const instance = axios.create();

// Override timeout default for the library // Now all requests using this instance 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 });

## Interceptors

You can intercept requests or responses before they are handled by `then` or `catch`.

js // Add a request interceptor 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);

});

// Add a response interceptor axios.interceptors.response.use(function (response) {

// Any status code that lie within the range of 2xx cause this function to trigger
// Do something with response data
return response;

}, function (error) {

// Any status codes that falls outside the range of 2xx cause this function to trigger
// Do something with response error
return Promise.reject(error);

});

If you need to remove an interceptor later you can.

js const myInterceptor = axios.interceptors.request.use(function () {/.../}); axios.interceptors.request.eject(myInterceptor);

You can also clear all interceptors for requests or responses.

js const instance = axios.create(); instance.interceptors.request.use(function () {/.../}); instance.interceptors.request.clear(); // Removes interceptors from requests instance.interceptors.response.use(function () {/.../}); instance.interceptors.response.clear(); // Removes interceptors from responses

You can add interceptors to a custom instance of axios.

js const instance = axios.create(); instance.interceptors.request.use(function () {/.../});

When you add request interceptors, they are presumed to be asynchronous by default. This can cause a delay
in the execution of your axios request when the main thread is blocked (a promise is created under the hood for
the interceptor and your request gets put on the bottom of the call stack). If your request interceptors are synchronous you can add a flag
to the options object that will tell axios to run the code synchronously and avoid any delays in request execution.

js axios.interceptors.request.use(function (config) { config.headers.test = 'I am only a header!'; return config; }, null, { synchronous: true });

If you want to execute a particular interceptor based on a runtime check,
you can add a `runWhen` function to the options object. The interceptor will not be executed **if and only if** the return
of `runWhen` is `false`. The function will be called with the config
object (don't forget that you can bind your own arguments to it as well.) This can be handy when you have an
asynchronous request interceptor that only needs to run at certain times.

js function onGetCall(config) { return config.method === 'get'; } axios.interceptors.request.use(function (config) { config.headers.test = 'special get headers'; return config; }, null, { runWhen: onGetCall });

### Multiple Interceptors

Given you add multiple response interceptors
and when the response was fulfilled
- then each interceptor is executed
- then they are executed in the order they were added
- then only the last interceptor's result is returned
- then every interceptor receives the result of its predecessor
- and when the fulfillment-interceptor throws
    - then the following fulfillment-interceptor is not called
    - then the following rejection-interceptor is called
    - once caught, another following fulfill-interceptor is called again (just like in a promise chain).

Read [the interceptor tests](./test/specs/interceptors.spec.js) for seeing all this in code.

## Error Types

There are many different axios error messages that can appear that can provide basic information about the specifics of the error and where opportunities may lie in debugging.

The general structure of axios errors is as follows:
| Property  | Definition  |
| -------- | ----------  |
| message  | A quick summary of the error message and the status it failed with. |
| name     | This defines where the error originated from. For axios, it will always be an 'AxiosError'. |
| stack    | Provides the stack trace of the error. | 
| config   | An axios config object with specific instance configurations defined by the user from when the request was made |
| code     | Represents an axios identified error. The table below lists out specific definitions for internal axios error.  |
| status   | HTTP response status code. See [here](https://en.wikipedia.org/wiki/List_of_HTTP_status_codes) for common HTTP response status code meanings. 

Below is a list of potential axios identified error
| Code  |  Definition   |
| -------- | ----------  |
| ERR_BAD_OPTION_VALUE | Invalid or unsupported value provided in axios configuration. |
| ERR_BAD_OPTION | Invalid option provided in axios configuration. |
| ECONNABORTED | Request timed out due to exceeding timeout specified in axios configuration. |
| ETIMEDOUT | Request timed out due to exceeding default axios timelimit. |
| ERR_NETWORK | Network-related issue.
| ERR_FR_TOO_MANY_REDIRECTS | Request is redirected too many times; exceeds max redirects specified in axios configuration.
| ERR_DEPRECATED | Deprecated feature or method used in axios. 
| ERR_BAD_RESPONSE | Response cannot be parsed properly or is in an unexpected format. 
| ERR_BAD_REQUEST | Requested has unexpected format or missing required parameters. |
| ERR_CANCELED | Feature or method is canceled explicitly by the user.   
| ERR_NOT_SUPPORT | Feature or method not supported in the current axios environment. 
| ERR_INVALID_URL | Invalid URL provided for axios request.

## Handling Errors

the default behavior is to reject every response that returns with a status code that falls out of the range of 2xx and treat it as an error.

js axios.get('/user/12345') .catch(function (error) {

if (error.response) {
  // The request was made and the server responded with a status code
  // that falls out of the range of 2xx
  console.log(error.response.data);
  console.log(error.response.status);
  console.log(error.response.headers);
} else if (error.request) {
  // The request was made but no response was received
  // `error.request` is an instance of XMLHttpRequest in the browser and an instance of
  // http.ClientRequest in node.js
  console.log(error.request);
} else {
  // Something happened in setting up the request that triggered an Error
  console.log('Error', error.message);
}
console.log(error.config);

});

Using the `validateStatus` config option, you can override the default condition (status >= 200 && status < 300) and define HTTP code(s) that should throw an error.

js axios.get('/user/12345', { validateStatus: function (status) {

return status < 500; // Resolve only if the status code is less than 500

} })

Using `toJSON` you get an object with more information about the HTTP error.

js axios.get('/user/12345') .catch(function (error) {

console.log(error.toJSON());

});

## Cancellation

### AbortController

Starting from `v0.22.0` Axios supports AbortController to cancel requests in fetch API way:

js const controller = new AbortController();

axios.get('/foo/bar', { signal: controller.signal }).then(function(response) { //... }); // cancel the request controller.abort()

### CancelToken `👎deprecated`

You can also cancel a request using a *CancelToken*.

> The axios cancel token API is based on the withdrawn [cancellable promises proposal](https://github.com/tc39/proposal-cancelable-promises).

> This API is deprecated since v0.22.0 and shouldn't be used in new projects

You can create a cancel token using the `CancelToken.source` factory as shown below:

js const CancelToken = axios.CancelToken; const 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

} });

axios.post('/user/12345', { name: 'new name' }, { cancelToken: source.token })

// cancel the request (the message parameter is optional) source.cancel('Operation canceled by the user.');

You can also create a cancel token by passing an executor function to the `CancelToken` constructor:

js const CancelToken = axios.CancelToken; let 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();

> **Note:** you can cancel several requests with the same cancel token/abort controller.
> If a cancellation token is already cancelled at the moment of starting an Axios request, then the request is cancelled immediately, without any attempts to make a real request.

> During the transition period, you can use both cancellation APIs, even for the same request:

## Using `application/x-www-form-urlencoded` format

### URLSearchParams

By default, axios serializes JavaScript objects to `JSON`. To send data in the [`application/x-www-form-urlencoded` format](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST) instead, you can use the [`URLSearchParams`](https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams) API, which is [supported](http://www.caniuse.com/#feat=urlsearchparams) in the vast majority of browsers,and [ Node](https://nodejs.org/api/url.html#url_class_urlsearchparams) starting with v10 (released in 2018).

js const params = new URLSearchParams({ foo: 'bar' }); params.append('extraparam', 'value'); axios.post('/foo', params);

### Query string (Older browsers)

For compatibility with very old browsers, there is a [polyfill](https://github.com/WebReflection/url-search-params) available (make sure to polyfill the global environment).

Alternatively, you can encode data using the [`qs`](https://github.com/ljharb/qs) library:

js const qs = require('qs'); axios.post('/foo', qs.stringify({ 'bar': 123 }));

Or in another way (ES6),

js import qs from 'qs'; const data = { 'bar': 123 }; const options = { method: 'POST', headers: { 'content-type': 'application/x-www-form-urlencoded' }, data: qs.stringify(data), url, }; axios(options);

### Older Node.js versions

For older Node.js engines, you can use the [`querystring`](https://nodejs.org/api/querystring.html) module as follows:

js const querystring = require('querystring'); axios.post('https://something.com/', querystring.stringify({ foo: 'bar' }));

You can also use the [`qs`](https://github.com/ljharb/qs) library.

> **Note**: The `qs` library is preferable if you need to stringify nested objects, as the `querystring` method has [known issues](https://github.com/nodejs/node-v0.x-archive/issues/1665) with that use case.

### 🆕 Automatic serialization to URLSearchParams

Axios will automatically serialize the data object to urlencoded format if the content-type header is set to "application/x-www-form-urlencoded".

js const data = { x: 1, arr: [1, 2, 3], arr2: [1, [2], 3], users: [{name: 'Peter', surname: 'Griffin'}, {name: 'Thomas', surname: 'Anderson'}], };

await axios.postForm('https://postman-echo.com/post', data, {headers: {'content-type': 'application/x-www-form-urlencoded'}} );

The server will handle it as:

js {

x: '1',
'arr[]': [ '1', '2', '3' ],
'arr2[0]': '1',
'arr2[1][0]': '2',
'arr2[2]': '3',
'arr3[]': [ '1', '2', '3' ],
'users[0][name]': 'Peter',
'users[0][surname]': 'griffin',
'users[1][name]': 'Thomas',
'users[1][surname]': 'Anderson'

}

If your backend body-parser (like `body-parser` of `express.js`) supports nested objects decoding, you will get the same object on the server-side automatically

```js
  var app = express();

  app.use(bodyParser.urlencoded({ extended: true })); // support encoded bodies

  app.post('/', function (req, res, next) {
     // echo body as JSON
     res.send(JSON.stringify(req.body));
  });

  server = app.listen(3000);
```

## Using `multipart/form-data` format

### FormData

To send the data as a `multipart/formdata` you need to pass a formData instance as a payload.
Setting the `Content-Type` header is not required as Axios guesses it based on the payload type.

```js
const formData = new FormData();
formData.append('foo', 'bar');

axios.post('https://httpbin.org/post', formData);
```

In node.js, you can use the [`form-data`](https://github.com/form-data/form-data) library as follows:

```js
const FormData = require('form-data');

const form = new FormData();
form.append('my_field', 'my value');
form.append('my_buffer', new Buffer(10));
form.append('my_file', fs.createReadStream('/foo/bar.jpg'));

axios.post('https://example.com', form)
```

### 🆕 Automatic serialization to FormData

Starting from `v0.27.0`, Axios supports automatic object serialization to a FormData object if the request `Content-Type`
header is set to `multipart/form-data`.

The following request will submit the data in a FormData format (Browser & Node.js):

```js
import axios from 'axios';

axios.post('https://httpbin.org/post', {x: 1}, {
  headers: {
    'Content-Type': 'multipart/form-data'
  }
}).then(({data}) => console.log(data));
```

In the `node.js` build, the ([`form-data`](https://github.com/form-data/form-data)) polyfill is used by default.

You can overload the FormData class by setting the `env.FormData` config variable,
but you probably won't need it in most cases:

```js
const axios = require('axios');
var FormData = require('form-data');

axios.post('https://httpbin.org/post', {x: 1, buf: new Buffer(10)}, {
  headers: {
    'Content-Type': 'multipart/form-data'
  }
}).then(({data}) => console.log(data));
```

Axios FormData serializer supports some special endings to perform the following operations:

- `{}` - serialize the value with JSON.stringify
- `[]` - unwrap the array-like object as separate fields with the same key

> **Note**: unwrap/expand operation will be used by default on arrays and FileList objects

FormData serializer supports additional options via `config.formSerializer: object` property to handle rare cases:

- `visitor: Function` - user-defined visitor function that will be called recursively to serialize the data object
to a `FormData` object by following custom rules.

- `dots: boolean = false` - use dot notation instead of brackets to serialize arrays and objects;

- `metaTokens: boolean = true` - add the special ending (e.g `user{}: '{"name": "John"}'`) in the FormData key.
The back-end body-parser could potentially use this meta-information to automatically parse the value as JSON.

- `indexes: null|false|true = false` - controls how indexes will be added to unwrapped keys of `flat` array-like objects

    - `null` - don't add brackets (`arr: 1`, `arr: 2`, `arr: 3`)
    - `false`(default) - add empty brackets (`arr[]: 1`, `arr[]: 2`, `arr[]: 3`)
    - `true` - add brackets with indexes  (`arr[0]: 1`, `arr[1]: 2`, `arr[2]: 3`)

Let's say we have an object like this one:

```js
const obj = {
  x: 1,
  arr: [1, 2, 3],
  arr2: [1, [2], 3],
  users: [{name: 'Peter', surname: 'Griffin'}, {name: 'Thomas', surname: 'Anderson'}],
  'obj2{}': [{x:1}]
};
```

The following steps will be executed by the Axios serializer internally:

```js
const formData = new FormData();
formData.append('x', '1');
formData.append('arr[]', '1');
formData.append('arr[]', '2');
formData.append('arr[]', '3');
formData.append('arr2[0]', '1');
formData.append('arr2[1][0]', '2');
formData.append('arr2[2]', '3');
formData.append('users[0][name]', 'Peter');
formData.append('users[0][surname]', 'Griffin');
formData.append('users[1][name]', 'Thomas');
formData.append('users[1][surname]', 'Anderson');
formData.append('obj2{}', '[{"x":1}]');
```

Axios supports the following shortcut methods: `postForm`, `putForm`, `patchForm`
which are just the corresponding http methods with the `Content-Type` header preset to `multipart/form-data`.

## Files Posting

You can easily submit a single file:

```js
await axios.postForm('https://httpbin.org/post', {
  'myVar' : 'foo',
  'file': document.querySelector('#fileInput').files[0]
});
```

or multiple files as `multipart/form-data`:

```js
await axios.postForm('https://httpbin.org/post', {
  'files[]': document.querySelector('#fileInput').files
});
```

`FileList` object can be passed directly:

```js
await axios.postForm('https://httpbin.org/post', document.querySelector('#fileInput').files)
```

All files will be sent with the same field names: `files[]`.

## 🆕 HTML Form Posting (browser)

Pass HTML Form element as a payload to submit it as `multipart/form-data` content.

```js
await axios.postForm('https://httpbin.org/post', document.querySelector('#htmlForm'));
```

`FormData` and `HTMLForm` objects can also be posted as `JSON` by explicitly setting the `Content-Type` header to `application/json`:

```js
await axios.post('https://httpbin.org/post', document.querySelector('#htmlForm'), {
  headers: {
    'Content-Type': 'application/json'
  }
})
```

For example, the Form

```html
<form id="form">
  <input type="text" name="foo" value="1">
  <input type="text" name="deep.prop" value="2">
  <input type="text" name="deep prop spaced" value="3">
  <input type="text" name="baz" value="4">
  <input type="text" name="baz" value="5">

  <select name="user.age">
    <option value="value1">Value 1</option>
    <option value="value2" selected>Value 2</option>
    <option value="value3">Value 3</option>
  </select>

  <input type="submit" value="Save">
</form>
```

will be submitted as the following JSON object:

```js
{
  "foo": "1",
  "deep": {
    "prop": {
      "spaced": "3"
    }
  },
  "baz": [
    "4",
    "5"
  ],
  "user": {
    "age": "value2"
  }
}

Sending Blobs/Files as JSON (base64) is not currently supported.

🆕 Progress capturing

Axios supports both browser and node environments to capture request upload/download progress.

await axios.post(url, data, {
  onUploadProgress: function (axiosProgressEvent) {
    /*{
      loaded: number;
      total?: number;
      progress?: number; // in range [0..1]
      bytes: number; // how many bytes have been transferred since the last trigger (delta)
      estimated?: number; // estimated time in seconds
      rate?: number; // upload speed in bytes
      upload: true; // upload sign
    }*/
  },

  onDownloadProgress: function (axiosProgressEvent) {
    /*{
      loaded: number;
      total?: number;
      progress?: number;
      bytes: number; 
      estimated?: number;
      rate?: number; // download speed in bytes
      download: true; // download sign
    }*/
  }
});  

You can also track stream upload/download progress in node.js:

const {data} = await axios.post(SERVER_URL, readableStream, {
   onUploadProgress: ({progress}) => {
     console.log((progress * 100).toFixed(2));
   },
  
   headers: {
    'Content-Length': contentLength
   },

   maxRedirects: 0 // avoid buffering the entire stream
});
````

> **Note:**
> Capturing FormData upload progress is currently not currently supported in node.js environments.

> **⚠️ Warning**
> It is recommended to disable redirects by setting maxRedirects: 0 to upload the stream in the **node.js** environment,
> as follow-redirects package will buffer the entire stream in RAM without following the "backpressure" algorithm.


## 🆕 Rate limiting

Download and upload rate limits can only be set for the http adapter (node.js):

js const {data} = await axios.post(LOCAL_SERVER_URL, myBuffer, { onUploadProgress: ({progress, rate}) => {

console.log(`Upload [${(progress*100).toFixed(2)}%]: ${(rate / 1024).toFixed(2)}KB/s`)

},

maxRate: [100 * 1024], // 100KB/s limit });

## Semver

Until axios reaches a `1.0` release, breaking changes will be released with a new minor version. For example `0.5.1`, and `0.5.4` will have the same API, but `0.6.0` will have breaking changes.

## Promises

axios depends on a native ES6 Promise implementation to be [supported](https://caniuse.com/promises).
If your environment doesn't support ES6 Promises, you can [polyfill](https://github.com/jakearchibald/es6-promise).

## TypeScript

axios includes [TypeScript](https://typescriptlang.org) definitions and a type guard for axios errors.

typescript let user: User = null; try { const { data } = await axios.get('/user?ID=12345'); user = data.userDetails; } catch (error) { if (axios.isAxiosError(error)) {

handleAxiosError(error);

} else {

handleUnexpectedError(error);

} } ```

Because axios dual publishes with an ESM default export and a CJS module.exports, there are some caveats. The recommended setting is to use "moduleResolution": "node16" (this is implied by "module": "node16"). Note that this requires TypeScript 4.7 or greater. If use ESM, your settings should be fine. If you compile TypeScript to CJS and you can’t use "moduleResolution": "node 16", you have to enable esModuleInterop. If you use TypeScript to type check CJS JavaScript code, your only option is to use "moduleResolution": "node16".

Online one-click setup

You can use Gitpod, an online IDE(which is free for Open Source) for contributing or running the examples online.

Resources

• Changelog
• Ecosystem
• Contributing Guide
• Code of Conduct

Credits

axios is heavily inspired by the $http service provided in AngularJS. Ultimately axios is an effort to provide a standalone $http-like service for use outside of AngularJS.

License

MIT