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# PHProjectTypeDescriptionInvalidator

A protocol that you use to tell the project when and how to invalidate type and footer text.

```
protocol PHProjectTypeDescriptionInvalidator : NSObjectProtocol
```

## Overview

An object adheres to this protocol to implement custom behavior when you invalidate project information, such as type description and footer text.

## Topics

### Invalidating a Project Type

[`func invalidateTypeDescription(for: PHProjectType)`](/documentation/PhotosUI/PHProjectTypeDescriptionInvalidator/invalidateTypeDescription(for:))

Invalidates the type description for the given project type.

[`func invalidateFooterText(forSubtypesOf: PHProjectType)`](/documentation/PhotosUI/PHProjectTypeDescriptionInvalidator/invalidateFooterText(forSubtypesOf:))

Invalidates the footer text for the subtypes of the given project type.

## Relationships

### Inherits From

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

---

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