Command Basics

WebCAD's command system allows you to create and register custom commands.

Online Examples

Example	Description	Link
Simple Command	Basic command structure example	Online Demo{target="_blank"}
Register Command	CommandRegistry usage	Online Demo{target="_blank"}
Command with Preview	Preview drawing example	Online Demo{target="_blank"}
State Machine Command	Multi-step command example	Online Demo{target="_blank"}

Command Structure

A command class must have a main() method as the entry point:

// Command class must have a main() method as the entry point
export class MyCommand {
  async main(): Promise<void> {
    // Command logic
    console.log('Command executed');
  }
}

Register Command

Use CommandRegistry to register a command:

import { CommandRegistry, CommandDefinition, CommandOptions } from 'vjcad';

// Create command options
const options = new CommandOptions();
options.useAutoComplete = true;  // Enable auto-complete

// Register command
const cmdDef = new CommandDefinition(
  'MYCMD',           // Command name (uppercase)
  'My command description',  // Description
  MyCommand,          // Command class
  options             // Options
);
CommandRegistry.regist(cmdDef);

Get and Execute Command

// Get command
const cmd = CommandRegistry.item('MYCMD');

// Execute command
await Engine.editor.executerWithOp('MYCMD');

CommandOptions

Property	Type	Description
useAutoComplete	boolean	Enable command line auto-complete
transparent	boolean	Transparent command (can be called within other commands)
modal	boolean	Modal command

CommandDefinition

Property	Type	Description
name	string	Command name (uppercase)
description	string	Command description
commandClass	Class	Command class
options	CommandOptions	Command options

Command Lifecycle

Command Categories

WebCAD includes various types of built-in commands:

Type	Examples
Drawing Commands	LINE, CIRCLE, ARC, PLINE
Modify Commands	MOVE, COPY, ROTATE, SCALE
View Commands	ZOOM, PAN, REGEN
Edit Commands	ERASE, TRIM, EXTEND
Property Commands	LAYER, COLOR, LINETYPE

Next Steps

• Command Architecture - Deep dive into command system architecture
• Input System - Get user input
• Create Command - Complete command examples
• Point Picking Guide - Detailed point picking tutorial
• Entity Selection Guide - Detailed entity selection tutorial
• Command Design Patterns - Learn different command design patterns