Event.md

Event

Namespace: SpawnDev.SpawnJS.JSObjects
Inheritance: SpawnJSObject -> Event
MDN Reference: Event on MDN
Source: SpawnDev.SpawnJS/JSObjects/DOM/Event.cs

The Event interface represents an event which takes place on an EventTarget. It is the base class for all event types in SpawnDev.SpawnJS - MouseEvent, KeyboardEvent, TouchEvent, CustomEvent, etc. all inherit from Event. It provides common properties like type, target, and bubbling behavior, plus methods for controlling event propagation.

Constructor

// From existing reference (deserialization)
public Event(SpawnJSObjectReference _ref)

Properties

Property	Type	Description
Type	string	The name of the event (e.g., "click", "keydown", "resize").
Target	EventTarget	The original target that dispatched the event.
CurrentTarget	EventTarget?	The target currently processing the event (during bubbling/capture).
EventPhase	int	The phase of the event flow: 0=NONE, 1=CAPTURING, 2=AT_TARGET, 3=BUBBLING.
Bubbles	bool	Whether the event bubbles up through the DOM.
Cancelable	bool	Whether the event can be cancelled via preventDefault().
DefaultPrevented	bool	Whether preventDefault() was called.
Composed	bool	Whether the event can cross shadow DOM boundaries.
IsTrusted	bool	True if the event was initiated by the browser (not by script).
TimeStamp	double	The time the event was created (milliseconds).

Typed Target Accessors

Method	Return Type	Description
TargetAs<T>()	T	Get Target cast to a specific EventTarget subclass.
CurrentTargetAs<T>()	T	Get CurrentTarget cast to a specific EventTarget subclass.

Methods

Method	Return Type	Description
PreventDefault()	void	Cancel the event's default action (if cancelable).
StopPropagation()	void	Stop the event from propagating to parent elements. Does not prevent other listeners on the current element.
StopImmediatePropagation()	void	Stop propagation AND prevent remaining listeners on the current element from being called.
ComposedPath()	Array<EventTarget>	Get the event's propagation path (array of EventTargets).

Generic Variant: Event<TTarget>

public class Event<TTarget> : Event where TTarget : EventTarget

Overrides the Target property to return the specific target type directly.

Property	Type	Description
Target	TTarget	The event target, strongly typed.

Example

void HandleClick(Event e)
{
    Console.WriteLine($"Event type: {e.Type}");         // "click"
    Console.WriteLine($"Bubbles: {e.Bubbles}");          // true
    Console.WriteLine($"Trusted: {e.IsTrusted}");        // true (if user-initiated)
    Console.WriteLine($"Timestamp: {e.TimeStamp}ms");

    // Get target as specific type
    using var target = e.TargetAs<HTMLElement>();
    Console.WriteLine($"Target tag: {target.TagName}");

    // Cancel default behavior
    if (e.Cancelable)
    {
        e.PreventDefault();
    }

    // Stop bubbling
    e.StopPropagation();
}

element.OnClick += HandleClick;

Example - Event<TTarget>

// When the target type is known
void HandleInput(Event<HTMLInputElement> e)
{
    // Target is already typed - no casting needed
    string value = e.Target.Value;
    Console.WriteLine($"Input value: {value}");
}