Build Multiple Asset Picker
Learn how to request device photo library permissions from the user, then fetch the photo library's collections when authorized.
In this episode, learn how to display the various image collection titles in the asset picker's table view.
Set up the picker's table to navigate to the various photo collections, then set up the picker's collection view to load and display the collections' photos.
Persist photo selections between asset picker collections such that selection checkmarks display appropriately.
Use PHCachingImageManager to cache the images in and adjacent to the visible scrolling window, then load the collection view's images from that cache.
Manipulate Assets to Generate Collages
Create a photo album for the collages (i.e. "Stitches") or fetch the album if it already exists, then set up a collection view to display that album's images.
Create a new photo asset with a collage of the selected images, save it to the Stitches album, then load a high quality version of the image for display.
"Favorite," "unfavorite" and delete images; set the photo picker's selected image set to the assets referenced in the collage's adjustment data so the user can edit the selections to update the collage.
Implement observers to detect changes in the device's photo library, then update the app's photo preview, table view and collection view appropriately.
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