From 458c0cd91ee9529d89fded923946507d82b1126a Mon Sep 17 00:00:00 2001
From: Allan Jardine <allan@stargazer>
Date: Wed, 11 Jul 2018 10:41:08 +0100
Subject: [PATCH] New - button: Download button

---
 buttons/button.download.js | 113 +++++++++++++++++++++++++++++++++++++
 1 file changed, 113 insertions(+)
 create mode 100644 buttons/button.download.js

diff --git a/buttons/button.download.js b/buttons/button.download.js
new file mode 100644
index 0000000..7d3534e
--- /dev/null
+++ b/buttons/button.download.js
@@ -0,0 +1,113 @@
+/*! Download button for Buttons
+ * 2018 SpryMedia Ltd - MIT licensed - datatables.net/license
+ */
+
+/**
+ * @summary     Download Button
+ * @author      SpryMedia Ltd (www.datatables.net)
+ * @copyright   Copyright 2018 SpryMedia Ltd.
+ *
+ * License      MIT - http://datatables.net/license/mit
+ *
+ * A button that can be used to trigger a server-side action, typically a
+ * download of a file generated by the server. If server-side processing
+ * is enabled in the host table it will automatically add the last parameters
+ * used for a table draw allowing the script to output a file with the same
+ * order / search applied as the main table.
+ * 
+ * This is particularly useful when using server-side processing and wishing
+ * to allow user export of the data in a table. The default Buttons package
+ * will only export the data available on the client-side, while this button
+ * can be used to let the server generate the required file and then download
+ * it to the client-side.
+ *
+ * @example
+ *   // Download button
+ * 	var table = $('#example').DataTable({
+ * 		dom: 'Bfrtip',
+ * 		buttons: [
+ * 			{
+ * 				extend: 'download',
+ * 				url: '/api/download'
+ * 			}
+ * 		]
+ * 	});
+ */
+(function(window, document, $, undefined) {
+	function flattenJson(data, name, flattened) {
+		if (!flattened) {
+			flattened = {};
+		}
+
+		if (!name) {
+			name = '';
+		}
+
+		if ($.isPlainObject(data)) {
+			$.each(data, function(idx, val) {
+				if (name === '') {
+					flattenJson(val, idx, flattened);
+				} else {
+					flattenJson(val, name + '[' + idx + ']', flattened);
+				}
+			});
+		} else {
+			flattened[name] = data;
+		}
+
+		return flattened;
+	}
+
+	$.fn.dataTable.ext.buttons.download = {
+		text: 'Download',
+		action: function(e, dt, node, config) {
+			// Gather information to be submitted
+			var data = {};
+
+			if (dt.page.info().serverSide) {
+				$.extend(data, dt.ajax.params());
+			}
+
+			if (typeof config.data === 'function') {
+				config.data(data);
+			} else if (typeof config.data === 'object') {
+				$.extend(data, config.data);
+			}
+
+			// Convert data to a flat structure for submission
+			var flattened = flattenJson(data);
+
+			// Create an iframe
+			var iframe = $('<iframe/>')
+				.css({
+					border: 'none',
+					height: 0,
+					width: 0
+				})
+				.appendTo(document.body);
+
+			var contentDoc = iframe[0].contentWindow.document;
+			contentDoc.open();
+			contentDoc.close();
+
+			var form = $('<form/>', contentDoc)
+				.attr('method', config.type)
+				.attr('action', config.url)
+				.appendTo(contentDoc.body);
+
+			$.each(flattened, function(name, val) {
+				$('<input/>', contentDoc)
+					.attr('type', 'text')
+					.attr('name', name)
+					.attr('autocomplete', 'no')
+					.val(val)
+					.appendTo(form);
+			});
+
+			form.submit();
+		},
+		url: '',
+		type: 'POST',
+		data: {}
+	};
+})(window, document, jQuery);