Implemented /groups/permissions endpoint

ref #143

src/models/responses/ResponseUserGroupPermissions.ts

@@ -0,0 +1,43 @@
+import {
+    IsArray,
+    IsOptional
+} from "class-validator";
+import { UserGroup } from '../entities/UserGroup';
+import { ResponseObjectType } from '../enums/ResponseObjectType';
+import { IResponse } from './IResponse';
+import { ResponsePermission } from './ResponsePermission';
+
+/**
+ * Defines the group permission response (get /api/groups/:id/permissions).
+*/
+export class ResponseUserGroupPermissions implements IResponse {
+    /**
+    * The responseType.
+    * This contains the type of class/entity this response contains.
+    */
+    responseType: ResponseObjectType = ResponseObjectType.USERPERMISSIONS;
+
+    /**
+     * The permissions directly granted to the group.
+     */
+    @IsArray()
+    @IsOptional()
+    directlyGranted: ResponsePermission[] = new Array<ResponsePermission>();
+
+    /**
+     * Is just here for compatability.
+     */
+    @IsArray()
+    @IsOptional()
+    inherited: ResponsePermission[] = new Array<ResponsePermission>();
+
+    /**
+     * Creates a ResponseUserPermissions object from a group.
+     * @param group The group the response shall be build for.
+     */
+    public constructor(group: UserGroup) {
+        for (let permission of group.permissions) {
+            this.directlyGranted.push(permission.toResponse());
+        }
+    }
+}