29 lines
812 B
Markdown
29 lines
812 B
Markdown
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---
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sidebar_label: EventEmitter.once
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---
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# EventEmitter.once() method
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Like `on` but the listener will only be fired once and then it will be removed.
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**Signature:**
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```typescript
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class EventEmitter {
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once(event: EventType, handler: Handler): EventEmitter;
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}
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```
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## Parameters
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| Parameter | Type | Description |
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| --------- | ------------------------------------- | ------------------------------------------------- |
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| event | [EventType](./puppeteer.eventtype.md) | the event you'd like to listen to |
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| handler | [Handler](./puppeteer.handler.md) | the handler function to run when the event occurs |
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**Returns:**
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[EventEmitter](./puppeteer.eventemitter.md)
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`this` to enable you to chain method calls.
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