updated

added UserService and RoleService

Author: saadshams

src/model/service/RoleService.js

@@ -0,0 +1,15 @@
+//
+//  RoleService.js
+//  PureMVC JS Demo - EmployeeAdmin Microservice
+//
+//  Copyright(c) 2023 Saad Shams <[email protected]>
+//  Your reuse is governed by the Creative Commons Attribution 3.0 License
+//
+
+export class RoleService {
+
+    // See UserService
+    constructor() {
+    }
+
+}

src/model/service/UserService.js

@@ -0,0 +1,45 @@
+//
+//  UserService.js
+//  PureMVC JS Demo - EmployeeAdmin Microservice
+//
+//  Copyright(c) 2023 Saad Shams <[email protected]>
+//  Your reuse is governed by the Creative Commons Attribution 3.0 License
+//
+
+import https from "node:https";
+
+export class UserService {
+
+    constructor() {}
+
+    // Simple Use Case:
+    // If the data is sourced externally, the Proxy first checks the database (UserData) to see if the data is
+    // available. If available, it returns the cached data to the Mediator. Otherwise, it contacts the UserService.
+    // Service classes retrieve data from external sources, manage network requests and parsing, and return data to
+    // the Proxy, which then caches it in the database for future use before returning it to the Mediator.
+
+    // Complex Use Case:
+    // A Command will come into play if the data retrieval involves multiple proxies and data sources,
+    // typically if the logic spans different domains.
+    // The Command encapsulates business logic, manages data retrieval, performs data transformation, and
+    // enforces business rules before returning the final data to the Mediator and its component.
+    findAllUsers() {
+        return new Promise((resolve, reject) => {
+            https.request({
+                method: "GET", hostname: "https://jsonplaceholder.typicode.com", path: "/users"
+            }, response => {
+                let buffers = [];
+                response.on("data", data => buffers.push(data));
+                response.on("end", () => {
+                    try {
+                        if(response.statusCode === 200)
+                            resolve(JSON.parse(Buffer.concat(buffers).toString()));
+                        else
+                            reject(JSON.parse(Buffer.concat(buffers).toString()));
+                    } catch(error) { reject(error); }
+                });
+            }).on("error", reject).end();
+        });
+    }
+
+}