A small xhr wrapper. Designed for use with browserify.

var xhr = require("xhr")

xhr({
    body: someJSONString,
    uri: "/foo",
    headers: {
        "Content-Type": "application/json"
    }
}, function (err, resp, body) {
    // resp === xhr
    // check resp.body or resp.statusCode
})

type XhrOptions = String | {
    useXDR: Boolean?,
    sync: Boolean?,
    uri: String,
    url: String,
    method: String?,
    timeout: Number?,
    headers: Object?,
    body: String?,
    json: Object?,
    withCredentials: Boolean?
}
xhr := (XhrOptions, Callback<Response>) => Request

the returned object is either an XMLHttpRequest instance or an XDomainRequest instance (if on IE8/IE9 && options.useXDR is set to true)

Your callback will be called once with the arguments ( Error, response , body ) where response is a response object containing { statusCode, body } and other properties of the XHR request and body will be either xhr.response, xhr.responseText or xhr.responseXML depending on the request type.

Your callback will be called with an Error if the resulting status of the request is either 0, 4xx or 5xx

If options is a string then it's a short hand for { method: "GET", uri: string }

Specify the method the XMLHttpRequest should be opened with. Passed to xhr.open. Defaults to "GET"

Specify whether this is a cross origin (CORS) request for IE<10. Switches IE to use XDomainRequest instead of XMLHttpRequest. Ignored in other browsers.

Note that headers cannot be set on an XDomainRequest instance.

Specify whether this is a synchrounous request. Note that when this is true the callback will be called synchronously. In most cases this option should not be used. Only use if you know what you are doing!

Pass in body to be send across the XMLHttpRequest. Generally should be a string. But anything that's valid as a parameter to xhr.send should work

The uri to send a request too. Passed to xhr.open. options.url and options.uri are aliases for each other.

An object of headers that should be set on the request. The key, value pair is passed to xhr.setRequestHeader

A numeric timeout to use for this xhr request. Defaults to 5 seconds. Ignored when options.sync is true.

A valid JSON serializable value to be send to the server. If this is set then we serialize the value and use that as the body. We also set the Content-Type to "application/json".

Additionally the response body is parsed as JSON

Specify whether user credentials are to be included in a cross-origin request. Sets xhr.withCredentials. Defaults to false.

For backward-compatibility defaults to true when deprecated options.cors is also true.

A wildcard * cannot be used in the Access-Control-Allow-Origin header when withCredentials is true. The header needs to specify your origin explicitly or browser will abort the request.