EventBus API

EventBus is the publish/subscribe bus; subsystems communicate through it.

Import

const { EventBus, VjmapextEvents } = vjmapext;

Usually use mapcadLayer.eventBus; no need to construct your own.

Methods

on(event, handler)

Subscribe.

Parameter	Type	Description
event	string	Event name
handler	Function	Handler

mapcadLayer.eventBus.on('entity:added', (data) => {
  console.log('entity added:', data.entity.id);
});

off(event, handler)

Unsubscribe. Pass the same function reference as in on.

Parameter	Type	Description
event	string	Event name
handler	Function	Handler to remove

emit(event, data?)

Emit an event.

Parameter	Type	Description
event	string	Event name
data	any	Optional payload

clear()

Remove all listeners.

VjmapextEvents

Typed event name constants:

const { VjmapextEvents } = vjmapext;
mapcadLayer.eventBus.on(VjmapextEvents.EntityAdded, handler);

Event reference

Entity events

Event	Constant	When	Payload
entity:added	EntityAdded	Entity added to store	{ entity }
entity:deleted	EntityDeleted	Entity removed	{ entity }
entity:modified	EntityModified	Property change	{ entity, styleOnly?: boolean }

Tips

entity:modified with styleOnly: true means style-only change (e.g. color), not geometry—property UI can use this to refresh selectively.

Mouse events

Event	Constant	When	Payload
entity:mouseenter	EntityMouseEnter	Pointer enters entity	{ entity, originalEvent }
entity:mouseleave	EntityMouseLeave	Pointer leaves entity	{ entity, originalEvent }
entity:click	EntityClick	Click entity	{ entity, originalEvent }
entity:dblclick	EntityDblClick	Double-click entity	{ entity, originalEvent }

Selection events

Event	Constant	When	Payload
selection:changed	SelectionChanged	Selection changes	{ selected: string[], deselected: string[] }

Command and mode events

Event	Constant	When	Payload
command:started	CommandStarted	Command starts	{ name }
command:ended	CommandEnded	Command ends	{ name }
mode:changed	ModeChanged	Edit/browse toggles	{ mode }

Input events

Event	Constant	When	Payload
input:started	InputStarted	Input starts	—
input:ended	InputEnded	Input ends	—
boxselect:started	BoxSelectStarted	Box select starts	—
boxselect:ended	BoxSelectEnded	Box select ends	—

System events

Event	Constant	When	Payload
render:requested	RenderRequested	Render requested	—
store:changed	StoreChanged	Store changed	—

Example

const bus = mapcadLayer.eventBus;

bus.on(VjmapextEvents.SelectionChanged, ({ selected, deselected }) => {
  console.log(`selected ${selected.length}, deselected ${deselected.length}`);
});

bus.on(VjmapextEvents.CommandStarted, ({ name }) => {
  console.log(`command started: ${name}`);
});

bus.on(VjmapextEvents.ModeChanged, ({ mode }) => {
  console.log(`mode: ${mode}`);
});

See also

• Events overview
• Entity lifecycle events
• Mouse events