> Documentation index: https://www.gooddata.ai/docs/gooddata-ui/llms.txt lists every page of these docs as Markdown.

# IHeaderPredicate

- Package: [@gooddata/sdk-ui](https://www.gooddata.ai/docs/gooddata-ui/latest/api-reference/sdk-ui/index.md)
- Kind: type-alias
- Source: https://github.com/gooddata/gooddata-ui-sdk/blob/rel/11.64/libs/sdk-ui/src/base/headerMatching/HeaderPredicate.ts
- Guides: [Make visualizations drillable](https://www.gooddata.ai/docs/gooddata-ui/latest/integrations/interactivity/drillable-items/index.md), [Header predicates](https://www.gooddata.ai/docs/gooddata-ui/latest/integrations/interactivity/predicates/index.md)

A function called for [IMappingHeader](https://www.gooddata.ai/docs/gooddata-ui/latest/api-reference/sdk-ui/sdk-ui.imappingheader/index.md) instances.

**Signature:**

```typescript
export type IHeaderPredicate = (header: IMappingHeader, context: IHeaderPredicateContext) => boolean;
```
**References:** [IMappingHeader](https://www.gooddata.ai/docs/gooddata-ui/latest/api-reference/sdk-ui/sdk-ui.imappingheader/index.md), [IHeaderPredicateContext](https://www.gooddata.ai/docs/gooddata-ui/latest/api-reference/sdk-ui/sdk-ui.iheaderpredicatecontext/index.md)

## Remarks

When the function returns true, it means the IMappingHeader is matched. See [documentation](https://www.gooddata.com/docs/gooddata-ui/latest/learn/add_interactivity/predicates) for more information.