then-request

A request library that returns promises and supports both browsers and node.js


Installation

npm install then-request

Usage

request(method, url, options, callback?)

The following examples all work on both client and server.

``js
var request = require('then-request');

request('GET', 'http://example.com').done(function (res) {
console.log(res.getBody());
});

request('POST', 'http://example.com/json-api', {json: {some: 'values'}}).getBody('utf8').then(JSON.parse).done(function (res) {
console.log(res);
});

var FormData = request.FormData;
var data = new FormData();

data.append('some', 'values');

request('POST', 'http://example.com/form-api', {form: data}).done(function (res) {
console.log(res.getBody());
});
`

Or with ES6

`js
import request, {FormData} from 'then-request';

request('GET', 'http://example.com').done((res) => {
console.log(res.getBody());
});

request('POST', 'http://example.com/json-api', {json: {some: 'values'}}).getBody('utf8').then(JSON.parse).done((res) => {
console.log(res);
});

var FormData = request.FormData;
var data = new FormData();

data.append('some', 'values');

request('POST', 'http://example.com/form-api', {form: data}).done((res) => {
console.log(res.getBody());
});
`

Method:

An HTTP method (e.g. GET, POST, PUT, DELETE or HEAD). It is not case sensitive.

URL:

A url as a string (e.g. http://example.com). Relative URLs are allowed in the browser.

Options:

- qs - an object containing querystring values to be appended to the uri
- headers - http headers (default: {})
- body - body for PATCH, POST and PUT requests. Must be a Buffer, ReadableStream or String (only strings are accepted client side)
- json - sets body but to JSON representation of value and adds Content-type: application/json. Does not have any affect on how the response is treated.
- form - You can pass a FormData instance to the form option, this will manage all the appropriate headers for you. Does not have any affect on how the response is treated.
- cache - only used in node.js (browsers already have their own caches) Can be 'memory', 'file' or your own custom implementaton (see https://github.com/ForbesLindesay/http-basic#implementing-a-cache).
- followRedirects - defaults to true but can be explicitly set to false on node.js to prevent then-request following redirects automatically.
- maxRedirects - sets the maximum number of redirects to follow before erroring on node.js (default: Infinity)
- allowRedirectHeaders (default: null) - an array of headers allowed for redirects (none if null).
- gzip - defaults to true but can be explicitly set to false on node.js to prevent then-request automatically supporting the gzip encoding on responses.
- agent - (default: false) - An Agent to controll keep-alive. When set to false use an Agent with default values.
- timeout (default: false) - times out if no response is returned within the given number of milliseconds.
- socketTimeout (default: false) - calls req.setTimeout internally which causes the request to timeout if no new data is seen for the given number of milliseconds. This option is ignored in the browser.
- retry (default: false) - retry GET requests. Set this to true to retry when the request errors or returns a status code greater than or equal to 400 (can also be a function that takes (err, req, attemptNo) => shouldRetry)
- retryDelay (default: 200) - the delay between retries (can also be set to a function that takes (err, res, attemptNo) => delay)
- maxRetries (default: 5) - the number of times to retry before giving up.


Returns:

A Promise is returned that eventually resolves to the Response. The resulting Promise also has an additional .getBody(encoding?) method that is equivallent to calling .then(function (res) { return res.getBody(encoding?); }).

$3

Note that even for status codes that represent an error, the promise will be resolved as the request succeeded. You can call getBody if you want to error on invalid status codes. The response has the following properties:

- statusCode - a number representing the HTTP status code
- headers - http response headers
- body - a string if in the browser or a buffer if on the server
- url - the URL that was requested (in the case of redirects on the server, this is the final url that was requested)

It also has a method getBody(encoding?) which looks like:

`js
function getBody(encoding) {
if (this.statusCode >= 300) {
var err = new Error('Server responded with status code ' + this.statusCode + ':\n' + this.body.toString(encoding));
err.statusCode = this.statusCode;
err.headers = this.headers;
err.body = this.body;
throw err;
}
return encoding ? this.body.toString(encoding) : this.body;
}
`

$3

`js
var FormData = require('then-request').FormData;
`

Form data either exposes the node.js module, form-data, or the builtin browser object FormData, as appropriate.

They have broadly the same API, with the exception that form-data handles node.js streams and Buffers, while FormData handles the browser's File` Objects.

License

MIT