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interface

events.default.NodeEventTarget

interface NodeEventTarget

The NodeEventTarget is a Node.js-specific extension to EventTarget that emulates a subset of the EventEmitter API.

  • type: string,
    callback: null | EventListenerOrEventListenerObject,
    options?: boolean | AddEventListenerOptions
    ): void;

    Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.

    The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.

    When set to true, options's capture prevents callback from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE. When false (or not present), callback will not be invoked when event's eventPhase attribute value is CAPTURING_PHASE. Either way, callback will be invoked if event's eventPhase attribute value is AT_TARGET.

    When set to true, options's passive indicates that the callback will not cancel the event by invoking preventDefault(). This is used to enable performance optimizations described in § 2.8 Observing event listeners.

    When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.

    If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.

    The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.

    MDN Reference

    type: string,
    listener: EventListener | EventListenerObject,
    options?: boolean | AddEventListenerOptions
    ): void;

    Adds a new handler for the type event. Any given listener is added only once per type and per capture option value.

    If the once option is true, the listener is removed after the next time a type event is dispatched.

    The capture option is not used by Node.js in any functional way other than tracking registered event listeners per the EventTarget specification. Specifically, the capture option is used as part of the key when registering a listener. Any individual listener may be added once with capture = false, and once with capture = true.

  • type: string,
    listener: (arg: any) => void
    ): this;

    Node.js-specific extension to the EventTarget class that emulates the equivalent EventEmitter API. The only difference between addListener() and addEventListener() is that addListener() will return a reference to the EventTarget.

  • event: Event
    ): boolean;

    Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.

  • type: string,
    arg: any
    ): boolean;

    Node.js-specific extension to the EventTarget class that dispatches the arg to the list of handlers for type.

    @returns

    true if event listeners registered for the type exist, otherwise false.

  • eventNames(): string[];

    Node.js-specific extension to the EventTarget class that returns an array of event type names for which event listeners are registered.

  • getMaxListeners(): number;

    Node.js-specific extension to the EventTarget class that returns the number of max event listeners.

  • type: string
    ): number;

    Node.js-specific extension to the EventTarget class that returns the number of event listeners registered for the type.

  • type: string,
    listener: (arg: any) => void,
    options?: EventListenerOptions
    ): this;

    Node.js-specific alias for eventTarget.removeEventListener().

  • type: string,
    listener: (arg: any) => void
    ): this;

    Node.js-specific alias for eventTarget.addEventListener().

  • type: string,
    listener: (arg: any) => void
    ): this;

    Node.js-specific extension to the EventTarget class that adds a once listener for the given event type. This is equivalent to calling on with the once option set to true.

  • type?: string
    ): this;

    Node.js-specific extension to the EventTarget class. If type is specified, removes all registered listeners for type, otherwise removes all registered listeners.

  • type: string,
    callback: null | EventListenerOrEventListenerObject,
    options?: boolean | EventListenerOptions
    ): void;

    Removes the event listener in target's event listener list with the same type, callback, and options.

    MDN Reference

    type: string,
    listener: EventListener | EventListenerObject,
    options?: boolean | EventListenerOptions
    ): void;

    Removes the event listener in target's event listener list with the same type, callback, and options.

  • type: string,
    listener: (arg: any) => void,
    options?: EventListenerOptions
    ): this;

    Node.js-specific extension to the EventTarget class that removes the listener for the given type. The only difference between removeListener() and removeEventListener() is that removeListener() will return a reference to the EventTarget.

  • n: number
    ): void;

    Node.js-specific extension to the EventTarget class that sets the number of max event listeners as n.