Mtf.Permissions 2.0.4

Mtf.Permissions Library Documentation

Overview

The Mtf.Permissions library simplifies permission management in .NET applications by providing tools to define, enforce, and apply permissions to UI controls and methods. It ensures secure access control based on user roles and permissions.

Installation

1. Add the Package:
   Install the library using the following command:

   dotnet add package Mtf.Permissions
   

2. Include the Namespace:
   Add the necessary namespace:

   using Mtf.Permissions;
   

Core Components

1. Class: PermissionManager

The PermissionManager class provides methods to manage permissions dynamically and validate user access to specific methods or UI components.

Properties

Methods

Example Usage

var permissionManager = new PermissionManager();
permissionManager.SetUser(mainForm, currentUser);
permissionManager.ApplyPermissionsOnControls(mainForm);

2. Attribute: RequirePermissionAttribute

Annotates methods that require specific permissions.

Properties

Example Usage

[RequirePermission(PermissionType.Admin)]
private void PerformAdminAction()
{
    // Admin-only logic
    MessageBox.Show("Admin action executed.");
}

3. Class: User

Represents a system user and their associated permissions.

Properties

4. Class: Permission

Defines a specific permission that can be assigned to users or groups.

Properties

5. Enum: PermissionType

An enumeration defining various permission types for your application. Extend this enum to add custom permission types.

Example Application

Scenario

A Windows Forms application with three user roles: Guest, Member, and Admin, each having varying levels of access to UI controls and functionality.

Code Example: MainForm

public partial class MainForm : Form
{
    private PermissionManager permissionManager;
    private User currentUser;

    public MainForm()
    {
        InitializeComponent();
        permissionManager = new PermissionManager();

        // Define users and their permissions
        var guest = new User { Username = "Guest", IndividualPermissions = new() };
        var member = new User { Username = "Member", IndividualPermissions = new() { new Permission { PermissionType = PermissionType.View } } };
        var admin = new User { Username = "Admin", IndividualPermissions = new() { new Permission { PermissionType = PermissionType.Admin } } };

        // Assign current user
        currentUser = admin;

        // Assign permissions to controls via the Tag property
        adminButton.Tag = nameof(AdminAction);
        viewButton.Tag = nameof(ViewAction);

        // Apply permissions
        permissionManager.SetUser(this, currentUser);
    }

    [RequirePermission(PermissionType.Admin)]
    private void AdminAction()
    {
        MessageBox.Show("Admin action executed.");
    }

    [RequirePermission(PermissionType.View)]
    private void ViewAction()
    {
        MessageBox.Show("View action executed.");
    }
}

Dynamic Permissions for UI Components

1. Controls (Control.Tag)
   Assign method names to the Tag property of controls. These methods must be decorated with [RequirePermission].

2. Menu Items
   Use ToolStripItem.Tag for menu items. The library dynamically enables or disables them based on the user's permissions.

3. Example: Dynamic ToolStrip Menu

fileMenuItem.Tag = nameof(OpenFile);
settingsMenuItem.Tag = nameof(ConfigureSettings);

[RequirePermission(PermissionType.View)]
private void OpenFile() { /* Logic */ }

[RequirePermission(PermissionType.Admin)]
private void ConfigureSettings() { /* Logic */ }

Error Handling

• Permission Validation:
  Use EnsurePermissions() to validate user permissions for critical operations. If the user lacks the necessary permissions, an UnauthorizedAccessException is thrown.

  permissionManager.EnsurePermissions();
  

• Null Checks:
  Ensure all methods handle null inputs gracefully (e.g., ArgumentNullException).

Best Practices

1. Use RequirePermissionAttribute:
   Clearly define required permissions for all restricted methods.

2. Leverage Groups:
   Organize permissions hierarchically using groups for better scalability.

3. Control Tags:
   Ensure all UI controls have meaningful Tag values pointing to their associated methods.

4. Caching:
   Cache user permissions for large applications to optimize performance.

Extensibility

• Add custom PermissionType values.
• Extend User and Group models to support additional metadata.