Fixed the problem that cannot be opened after creating a new file(#94)

Author: ACTom

Makefile

@@ -7,7 +7,7 @@ source_dir=$(build_dir)/source
 sign_dir=$(build_dir)/sign
 package_name=$(app_name)
 cert_dir=$(CURDIR)/../../key
-version+=0.0.19
+version+=0.0.20
 
 all: appstore
 

appinfo/info.xml

@@ -5,7 +5,7 @@
 	<name>Mind Map</name>
 	<summary>A Mind map editor</summary>
 	<description><![CDATA[This application enables Nextcloud users to open, save and edit mind map files in the web browser. If enabled, an entry in the New button at the top of the web browser the Mindmap file entry appears. When clicked, a new mindmap file opens in the browser and the file can be saved into the current Nextcloud directory.]]></description>
-	<version>0.0.19</version>
+	<version>0.0.20</version>
 	<licence>agpl</licence>
 	<author mail="[email protected]" homepage="https://actom.me">Jingtao Yan</author>
 	<namespace>Files_MindMap</namespace>

js/mindmap.js

@@ -216,7 +216,7 @@ var FilesMindMap = {
 			}
 
 			plugin.decode(data.filecontents).then(function(kmdata){
-				data.filecontents = JSON.stringify(kmdata);
+				data.filecontents = typeof kmdata === 'object' ? JSON.stringify(kmdata) : kmdata;
 				data.supportedWrite = true;
 				if (plugin.encode === null) {
 					data.writeable = false;
@@ -318,7 +318,11 @@ FilesMindMap.Extensions.KM = {
 	},
 	decode: function(data) {
 		return new Promise(function(resolve, reject) {
-			resolve(JSON.parse(data));
+			try {
+				resolve(JSON.parse(data));
+			} catch (e) {
+				resolve(data);
+			}
         });
 	}
 };