feat: add ajax headers and post data

README.md

@@ -60,10 +60,13 @@ import { saveAs } from 'file-saver';
 ```
 
 ```js
-FileSaver saveAs(Blob/File/Url, optional DOMString filename, optional Object { autoBom })
+FileSaver saveAs(Blob/File/Url, optional DOMString filename, optional Object { autoBom, headers, postData })
 ```
+Optional Object:
 
-Pass `{ autoBom: true }` if you want FileSaver.js to automatically provide Unicode text encoding hints (see: [byte order mark](https://en.wikipedia.org/wiki/Byte_order_mark)). Note that this is only done if your blob type has `charset=utf-8` set.
+- Pass `{ autoBom: true }` if you want FileSaver.js to automatically provide Unicode text encoding hints (see: [byte order mark](https://en.wikipedia.org/wiki/Byte_order_mark)). Note that this is only done if your blob type has `charset=utf-8` set.
+- Pass `{ headers: object }` if you want append headers when fetch data from remote url.
+- Pass `{ postData: object }` if you want send data when post data from remote url.
 
 Examples
 --------

src/FileSaver.js

@@ -33,15 +33,25 @@ function bom (blob, opts) {
 
 function download (url, name, opts) {
   var xhr = new XMLHttpRequest()
-  xhr.open('GET', url)
   xhr.responseType = 'blob'
   xhr.onload = function () {
     saveAs(xhr.response, name, opts)
   }
   xhr.onerror = function () {
     console.error('could not download file')
   }
-  xhr.send()
+  if (opts && opts.headers) {
+    for (var key in opts.headers) {
+      xhr.setRequestHeader(key, opts.headers[key])
+    }
+  }
+  if (opts && opts.postData) {
+    xhr.open('POST', url)
+    xhr.send(opts.postData)
+  } else {
+    xhr.open('GET', url)
+    xhr.send()
+  }
 }
 
 function corsEnabled (url) {