moves json readout to seperate function with callback

- adds function to get device fingerprint
- adds readJsonFromFile function with file name in 'wgt-private' and
callback function

js/app.js

@@ -14,7 +14,8 @@
  * limitations under the License. 	
  */
 
-var events;
+var events = null;
+var deviceId = null;
 var eventsTimeStamp = 0;
 
 (function() {
@@ -24,22 +25,25 @@ var eventsTimeStamp = 0;
         ctxContent,
         center,
         watchRadius;
+    
 
-    function readJSON(path) {
-    	/* - requests permission to view media storage
-    	 * - resolves the file 'calendarevents'
-    	 * - opens stream and reads entire file as json
-    	 */
+    function getJsonFile(name, callback) {
     	
+    	/* successful resolution of wgt-private */
     	function onsuccess(dir){
-            var dirfile = dir.resolve("calendarevents");
-            console.log(dirfile);
-           
-           /* for tizen 4.0, should work on 5.5 aswell but tizen 5.5 uses 'openFile' for Filereading */
+            var dirfile = null;
+            try {
+            	dirfile = dir.resolve(name);
+            } catch (exc) {
+            	console.log(exc.message)
+            }
+            
+            if(dirfile == null)
+            	return null;
             dirfile.openStream("r", function(fs) {
-    		events = JSON.parse(fs.read(dirfile.fileSize));
-    		fs.close();
-            })
+            	callback(JSON.parse(fs.read(dirfile.fileSize)));
+        		fs.close();
+                });
     	}
         
         function onerror(e){
@@ -56,8 +60,34 @@ var eventsTimeStamp = 0;
         
     	tizen.ppm.requestPermission("http://tizen.org/privilege/mediastorage", onsuccessPermission, onErrorPermission);
     }
+    
+    function readJSON(path) {
+    	/* - requests permission to view media storage
+    	 * - resolves the file 'calendarevents'
+    	 * - opens stream and reads entire file as json
+    	 */
+    	
+    	getJsonFile("calendarevents", function(eventlist) {events = eventlist;});
+    	console.log(events);
+    }
 
+    function getDeviceID() {
+    	// check if device id set already as global, if it is return
+    	if(deviceId != null)
+    		return;
+    	
+    	// otherwise, check if there is a devicefingerprint file in wft-private 
+    	getJsonFile("devicefingerprint", function(df) {deviceId = df;})
+    	// if there is, open it up and get your device ID from it
+    	
+    	// otherwise, ask the longitude server for a device fingerprint file
+    }
+    
     function getJSON() {
+    	
+    	/*if(deviceId == null) 
+    		return;
+    	*/
         var downloadRequest = new tizen.DownloadRequest('https://longitudecalendar.com/userinfo/107971745944668140075/calendarevents.json', 'wgt-private');
             tizen.systeminfo.getPropertyValue('NETWORK', function(networkInfo) {
                 if (networkInfo.networkType === 'NONE') {
@@ -360,6 +390,7 @@ var eventsTimeStamp = 0;
         // Draw the text for date
         // renderText(ctxContent, date, center.x, center.y + (watchRadius * 0.5), 25, "#999999");
         
+        console.log(events);
         if(events == null)
         	return;