Saving NSData Array to CoreData

Question

I'm picking an image from gallery and converting it to NSData. Later on I'm storing it in CoreData and retrieving later. But if I pick 2 images from the gallery, I want to store the `NSData info of both of them to an array and store that array to CoreData. But how an array can be saved to CoreData that I'm not able to figure out. Did go through other SO posts dealing with similar issue but they weren't of much help.

Also please note..I cannot store the array to Userdefaults or Document directory in this scenario because there are other data associated with the image like name,qty etc. and they are all stored in coredata and they should later be displayed in tableview. If just the images are stored using some other method and the other details stored using core-data, there won't be proper data populated in the tableview..

This link can help you... https://stackoverflow.com/questions/4266205/saving-pictures-in-core-data-in-to-many-relationship-environment — Alfa, Jan 18 '18 at 07:51

Alexey Kudlay · Accepted Answer · 2018-01-19T14:35:23.943

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Use entity as ImagesArray with relationship to many entities as Image. In its turn, the picture will have properties e.g. imageData (Binary Data), Name (String) etc. and relationship to one ImagesArray.

See example

Create ImagesArray entity with identifier or other properties for identification.

And then create Image entity with properties imageData (Binary Data), name (String) etc.

Entity ImagesArray will have relationship images to many entities Image.

Entity Image will have inverse relationship imagesArray to one entity ImagesArray

In code you will create set of entities Image with imageData, name etc.

Then create ImagesArray.

Add set of entities Image to ImagesArray's property (relationship) images.

Entity ImagesArray will have set of entities Image.

edited Jan 19 '18 at 14:35

answered Jan 18 '18 at 07:51

Alexey Kudlay

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can u explain in a bit more detail, @Alexey Kudlay – Jan 18 '18 at 08:01
@bvt, OK. A little bit later – Alexey Kudlay Jan 18 '18 at 08:49
Thanks for the answer, @Alexey Kudlay..I got some idea of what u said but not everything. In this case which array will hold my images..? The array of type `Image` or `Images`..? Also, how images will be stored..? in `NSData` format or as images itself..? – Jan 18 '18 at 09:30
@bvt, I did refresh answer. Also, how images will be stored..? - `NSData` – Alexey Kudlay Jan 18 '18 at 09:48
@bvt, did my decision help? – Alexey Kudlay Jan 18 '18 at 15:00
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/163456/discussion-between-bvt-and-alexey-kudlay). – Jan 19 '18 at 05:08

score 0 · Answer 2 · answered Jan 18 '18 at 07:54

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In my opinion saving an image to CoreData is not a correct approach to save images. You should save them in the app sand box and then store in CoreData the path.
Saying that you can save an Array by using NSValueTransformer, you can find an example here. but probably the best approach is to create a relation between a User entity and Image entity One-to-Many.

answered Jan 18 '18 at 07:54

Andrea

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I did see that link already @Andrea but couldn't get much help from it.. – Jan 18 '18 at 07:56

Saving NSData Array to CoreData

2 Answers2