Update folder structure

src/app/service/nodeservice.ts

@@ -0,0 +1,34 @@
+import { HttpClient } from '@angular/common/http';
+import { Injectable } from '@angular/core';
+
+import { TreeNode } from 'primeng/api';
+
+@Injectable()
+export class NodeService {
+
+    constructor(private http: HttpClient) { }
+
+    getFiles() {
+    return this.http.get<any>('assets/demo/data/files.json')
+      .toPromise()
+      .then(res => res.data as TreeNode[]);
+    }
+
+    getLazyFiles() {
+    return this.http.get<any>('assets/demo/data/files-lazy.json')
+      .toPromise()
+      .then(res => res.data as TreeNode[]);
+    }
+
+    getFilesystem() {
+    return this.http.get<any>('assets/demo/data/filesystem.json')
+      .toPromise()
+      .then(res => res.data as TreeNode[]);
+    }
+
+    getLazyFilesystem() {
+    return this.http.get<any>('assets/demo/data/filesystem-lazy.json')
+      .toPromise()
+      .then(res => res.data as TreeNode[]);
+    }
+}