35 lines
2.7 KiB
Markdown
35 lines
2.7 KiB
Markdown
---
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sidebar_label: EventEmitter
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---
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# EventEmitter class
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The EventEmitter class that many Puppeteer classes extend.
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#### Signature:
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```typescript
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export declare class EventEmitter<Events extends Record<EventType, unknown>> implements CommonEventEmitter<EventsWithWildcard<Events>>
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```
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**Implements:** [CommonEventEmitter](./puppeteer.commoneventemitter.md)<[EventsWithWildcard](./puppeteer.eventswithwildcard.md)<Events>>
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## Remarks
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This allows you to listen to events that Puppeteer classes fire and act accordingly. Therefore you'll mostly use [on](./puppeteer.eventemitter.on.md) and [off](./puppeteer.eventemitter.off.md) to bind and unbind to event listeners.
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The constructor for this class is marked as internal. Third-party code should not call the constructor directly or create subclasses that extend the `EventEmitter` class.
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## Methods
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| Method | Modifiers | Description |
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| --------------------------------------------------------------------------- | --------- | ------------------------------------------------------------------------------------------------ |
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| [addListener(type, handler)](./puppeteer.eventemitter.addlistener.md) | | Add an event listener. |
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| [emit(type, event)](./puppeteer.eventemitter.emit.md) | | Emit an event and call any associated listeners. |
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| [listenerCount(type)](./puppeteer.eventemitter.listenercount.md) | | Gets the number of listeners for a given event. |
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| [off(type, handler)](./puppeteer.eventemitter.off.md) | | Remove an event listener from firing. |
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| [on(type, handler)](./puppeteer.eventemitter.on.md) | | Bind an event listener to fire when an event occurs. |
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| [once(type, handler)](./puppeteer.eventemitter.once.md) | | Like <code>on</code> but the listener will only be fired once and then it will be removed. |
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| [removeAllListeners(type)](./puppeteer.eventemitter.removealllisteners.md) | | Removes all listeners. If given an event argument, it will remove only listeners for that event. |
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| [removeListener(type, handler)](./puppeteer.eventemitter.removelistener.md) | | Remove an event listener. |
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