Implemented permission getting

ref #6

src/models/responses/ResponsePermission.ts

@@ -0,0 +1,46 @@
+import {
+    IsInt,
+    IsNotEmpty,
+    IsObject
+} from "class-validator";
+import { Permission } from '../entities/Permission';
+import { Principal } from '../entities/Principal';
+import { PermissionAction } from '../enums/PermissionAction';
+import { PermissionTarget } from '../enums/PermissionTargets';
+
+/**
+ * Defines a track of given length.
+*/
+export class ResponsePermission {
+    /**
+     * Autogenerated unique id (primary key).
+     */
+    @IsInt()
+    id: number;;
+
+    /**
+     * The permissions's principal.
+     */
+    @IsObject()
+    @IsNotEmpty()
+    principal: Principal;
+
+    /**
+     * The permissions's target.
+     */
+    @IsNotEmpty()
+    target: PermissionTarget;
+
+    /**
+     * The permissions's action.
+     */
+    @IsNotEmpty()
+    action: PermissionAction;
+
+    public constructor(permission: Permission) {
+        this.id = permission.id;
+        this.principal = permission.principal;
+        this.target = permission.target;
+        this.action = permission.action;
+    }
+}