Plugin Framework

The Plugin infrastructure provides a complete system for extending applications with dynamically loaded modules, including discovery, loading, lifecycle management, UI integration, and inter-plugin communication.

Overview

• Dynamic Loading — Load plugins from DLLs at runtime with dependency isolation
• Component Discovery — Automatic discovery of menu and panel components
• Lifecycle Management — Enable/disable/remove plugins at runtime
• State Management — Both transient (in-memory) and persistent storage
• Message Bus Integration — Inter-plugin and plugin-host communication
• Asset Loading — Dynamic CSS/JS injection
• Platform Support — Desktop (dynamic) and WebAssembly (static reference)

Quick Start

1. Add Plugin Framework Services

builder.Services.AddPluginFramework();

2. Load Plugins

// From a directory (Desktop)
app.Services.UsePlugins("plugins");

// From a referenced assembly (WebAssembly)
app.Services.UsePlugin(typeof(MyPlugin.PluginManifest).Assembly);

3. Create a Plugin

// PluginManifest.cs
public class MyPluginManifest : IPluginManifest
{
    public string Id => "com.example.myplugin";
    public string Name => "My Plugin";
    public Version Version => new(1, 0, 0);
    public string Developer => "Example Corp";
    public string Description => "Does something useful";
}

Architecture

┌─────────────────────┐
│   Host Application  │
├─────────────────────┤
│    PluginState      │◀──── Manages all loaded plugins
│    PluginLoader     │◀──── Discovers & loads from assemblies
│    PluginContext    │◀──── Services injected into plugins
└──────────┬──────────┘
           │
           ▼
┌─────────────────────┐     ┌─────────────────────┐
│  Plugin Assembly A  │     │  Plugin Assembly B  │
├─────────────────────┤     ├─────────────────────┤
│  IPluginManifest    │     │  IPluginManifest    │
│  PluginMenu(s)      │     │  PluginContextPanel │
│  PluginContextPanel │     │  IConsumer<T>       │
└─────────────────────┘     └─────────────────────┘

Core Components

Component	Description
IPluginManifest	Required interface defining plugin metadata
PluginState	Singleton managing all loaded plugins
PluginLoader	Discovers and loads plugins from assemblies
PluginContext	Services and utilities injected into plugin components
PluginComponentBase	Base class for plugin Blazor components
PluginMenu	Base class for menu-based plugin UI
PluginContextPanel	Base class for side-panel plugin UI
PluginGuard	Error boundary wrapping plugin components

Topics

• Creating Plugins — How to build a plugin
• Plugin Components — UI component types and patterns
• State and Storage — Managing plugin data
• Lifecycle — Plugin loading, enabling, and events