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105 lines
1.9 KiB
Markdown
105 lines
1.9 KiB
Markdown
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---
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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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<table><thead><tr><th>
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Method
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</th><th>
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Modifiers
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</th><th>
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Description
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</th></tr></thead>
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<tbody><tr><td>
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[emit(type, event)](./puppeteer.eventemitter.emit.md)
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</td><td>
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</td><td>
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Emit an event and call any associated listeners.
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</td></tr>
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<tr><td>
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[listenerCount(type)](./puppeteer.eventemitter.listenercount.md)
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</td><td>
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</td><td>
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Gets the number of listeners for a given event.
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</td></tr>
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<tr><td>
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[off(type, handler)](./puppeteer.eventemitter.off.md)
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</td><td>
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</td><td>
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Remove an event listener from firing.
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</td></tr>
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<tr><td>
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[on(type, handler)](./puppeteer.eventemitter.on.md)
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</td><td>
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</td><td>
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Bind an event listener to fire when an event occurs.
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</td></tr>
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<tr><td>
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[once(type, handler)](./puppeteer.eventemitter.once.md)
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</td><td>
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</td><td>
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Like `on` but the listener will only be fired once and then it will be removed.
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</td></tr>
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<tr><td>
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[removeAllListeners(type)](./puppeteer.eventemitter.removealllisteners.md)
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</td><td>
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</td><td>
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Removes all listeners. If given an event argument, it will remove only listeners for that event.
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</td></tr>
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</tbody></table>
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