Update work with Data files.

server.js

@@ -39,35 +39,31 @@ app.engine('.hbs', hbs.engine);
 app.set('view engine', '.hbs');
 app.set('views', projectDir + 'layouts');
 
+const dataFiles = prepareListOfDataFiles(await fs.readdir('./data'));
+
 app.get('/', async (req, res) => {
-    let dataFiles = await fs.readdir('./data');
-    dataFiles = dataFiles
-        .filter((fileName) => fileName.split('.').pop() === 'json')
-        .map((fileName) => {
-            const splitName = fileName.split('.');
-            splitName.pop();
-            const name = splitName.join('');
-            return {
-                name,
-                active: (req.query.data) && req.query.data === name,
-            };
-        });
-
-    const jsonFileName = (req.query.data) ? req.query.data : 'default';
+    let jsonFileName = (req.query.data) ? req.query.data : 'default';
+    if (!jsonFileName || !await fsExtra.exists(`./data/${jsonFileName}.json`)) {
+        jsonFileName = 'default';
+    }
+
     const data = await fsExtra.readJson(`./data/${jsonFileName}.json`);
 
     Object.assign(data, {
         config: {
             projectDir,
-            dataFiles,
+            dataFiles: dataFiles.map((name) => {
+                return {
+                    name,
+                    active: jsonFileName === name,
+                };
+            }),
             cssUrl: config.get('cssUrl')
         }
     });
 
     data.helpers = {
-        include_partial(path) {
-            return projectDir + path;
-        }
+        include_partial: (path) => projectDir + path,
     }
 
     res.render('page-container', data);
@@ -145,6 +141,17 @@ function buildStyleFiles() {
         .pipe(gulp.dest('src/'))
 }
 
+function prepareListOfDataFiles(dataFiles) {
+    return dataFiles
+        .filter((fileName) => fileName.split('.').pop() === 'json')
+        .map((fileName) => {
+            const splitName = fileName.split('.');
+            splitName.pop();
+            return splitName.join('');
+        })
+        .sort();
+}
+
 // TODO:
 //
 // [v] Add Gulp for CSS/JS Styling