Support POST method when download is true

docs/docs.html

@@ -433,6 +433,7 @@ var csv = Papa.unparse({
 	error: undefined,
 	download: false,
 	downloadRequestHeaders: undefined,
+	downloadRequestBody: undefined,
 	skipEmptyLines: false,
 	chunk: undefined,
 	fastMode: undefined,
@@ -598,6 +599,14 @@ var csv = Papa.unparse({
 }</code>
 									</pre>
 							</tr>
+							<tr>
+								<td>
+									<code>downloadRequestBody</code>
+								</td>
+								<td>
+									If defined and the download property is true, a POST request will be made instead of a GET request and the passed argument will be set as the body of the request.
+								</td>
+							</tr>
 							<tr>
 								<td>
 									<code>skipEmptyLines</code>

papaparse.js

@@ -642,7 +642,7 @@ License: MIT
 				xhr.onerror = bindFunction(this._chunkError, this);
 			}
 
-			xhr.open('GET', this._input, !IS_WORKER);
+			xhr.open(this._config.downloadRequestBody ? 'POST' : 'GET', this._input, !IS_WORKER);
 			// Headers can only be set when once the request state is OPENED
 			if (this._config.downloadRequestHeaders)
 			{
@@ -661,7 +661,7 @@ License: MIT
 			}
 
 			try {
-				xhr.send();
+				xhr.send(this._config.downloadRequestBody);
 			}
 			catch (err) {
 				this._chunkError(err.message);