Plugin Basics

WebCAD provides a complete plugin system that supports extending commands, UI, and features.

Online Examples

Example	Description	Link
Basic Plugin	Example plugin structure	Online Demo{target="_blank"}
Validation Plugin	Data validation example	Online Demo{target="_blank"}
Standard Plugin	Standard PluginManager usage	Online Demo{target="_blank"}

Plugin Interface

import type { Plugin, PluginManifest, PluginContext } from 'vjcad';

// Plugin manifest
const manifest: PluginManifest = {
  id: 'my-plugin',              // Unique identifier
  name: 'My Plugin',            // Display name
  version: '1.0.0',             // Version
  author: 'Author Name',
  description: 'Plugin description',
  keywords: ['tool', 'CAD'],
  dependencies: [],             // Other plugin dependencies
  minEngineVersion: '1.0.0'     // Minimum engine version
};

// Plugin definition
const myPlugin: Plugin = {
  manifest,
  
  // Called when plugin is loaded (initialize, but do not activate features)
  async onLoad(context: PluginContext): Promise<void> {
    console.log('Plugin loaded');
  },
  
  // Called when plugin is activated (register commands, menus, etc.)
  async onActivate(context: PluginContext): Promise<void> {
    console.log('Plugin activated');
  },
  
  // Called when plugin is deactivated (clean up resources)
  async onDeactivate(context: PluginContext): Promise<void> {
    console.log('Plugin deactivated');
  },
  
  // Called when plugin is unloaded (final cleanup)
  async onUnload(context: PluginContext): Promise<void> {
    console.log('Plugin unloaded');
  }
};

export default myPlugin;

PluginManifest

The plugin manifest describes the plugin's basic information:

Property	Type	Required	Description
id	string	Yes	Unique identifier
name	string	Yes	Display name
version	string	Yes	Version
author	string	No	Author
description	string	No	Description
keywords	string[]	No	Keywords
dependencies	string[]	No	Dependency plugin IDs
minEngineVersion	string	No	Minimum engine version
homepage	string	No	Homepage URL
icon	string	No	Icon

PluginState

enum PluginState {
  Unloaded = 'unloaded',        // Not loaded
  Loading = 'loading',          // Loading
  Loaded = 'loaded',            // Loaded but not activated
  Activating = 'activating',    // Activating
  Active = 'active',            // Activated
  Deactivating = 'deactivating',// Deactivating
  Unloading = 'unloading',      // Unloading
  Error = 'error'               // Error
}

Lifecycle

Lifecycle Hooks

Hook	When Called	Purpose
onLoad	When plugin is loaded	Initialize, check dependencies, register resources
onActivate	When plugin is activated	Register commands, add UI, start features
onDeactivate	When plugin is deactivated	Unregister commands, remove UI, pause features
onUnload	When plugin is unloaded	Final cleanup, release resources, disconnect

Lifecycle Events

The plugin manager triggers corresponding events on each state transition:

Event	Trigger Time
PluginLoading	Before plugin loading starts
PluginLoaded	After plugin loading completes
PluginActivating	Before activation starts
PluginActivated	After activation completes
PluginDeactivating	Before deactivation starts
PluginDeactivated	After deactivation completes
PluginUnloading	Before unload starts
PluginUnloaded	After unload completes
PluginError	When a plugin error occurs

import { Engine, CadEvents } from 'vjcad';

// Listen for plugin load event
Engine.eventManager.on(CadEvents.PluginLoaded, (args) => {
  console.log('Plugin loaded:', args.pluginId);
});

// Listen for plugin unload event
Engine.eventManager.on(CadEvents.PluginUnloaded, (args) => {
  console.log('Plugin unloaded:', args.pluginId);
});

// Listen for plugin errors
Engine.eventManager.on(CadEvents.PluginError, (args) => {
  console.error('Plugin error:', args.pluginId, args.error);
});

Next Steps

• Plugin Context - PluginContext API
• Plugin Examples - complete plugin examples