---
title: "photoLibraryDidChange(_:)"
framework: photos
role: symbol
role_heading: Instance Method
path: "photos/phphotolibrarychangeobserver/photolibrarydidchange(_:)"
---

# photoLibraryDidChange(_:)

Tells your observer that a set of changes has occurred in the Photos library.

## Declaration

```swift
func photoLibraryDidChange(_ changeInstance: PHChange)
```

## Parameters

- `changeInstance`: An object representing the changes.

## Discussion

Discussion Use the provided PHChange object to find out which, if any, of the albums or collections you’re interested in have changed and get detailed change information. Call the change object’s changeDetailsForObject: method to get information about changes to an asset’s contents or metadata properties or about a collection’s metadata properties. Call the change object’s changeDetails(for:) to get information about changes to a collection’s list of members (or to any other fetch result). Photos calls this method on an arbitrary queue. If you need to update your app’s UI as a result of the change, dispatch to the main queue.