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32 lines
1.1 KiB
Markdown
32 lines
1.1 KiB
Markdown
---
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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<Key extends keyof EventsWithWildcard<Events>>(
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type: Key,
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handler: Handler<EventsWithWildcard<Events>[Key]>
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): this;
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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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| type | Key | the event you'd like to listen to |
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| handler | [Handler](./puppeteer.handler.md)<[EventsWithWildcard](./puppeteer.eventswithwildcard.md)<Events>\[Key\]> | the handler function to run when the event occurs |
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**Returns:**
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this
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`this` to enable you to chain method calls.
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