Keep 10 records to create/update in Rails -

using rails 4. calling api, returns shop , photos. when returns photos, 10 photos.

everytime call api, find_or_initialize_by shop, update shop details. @ same time, want update photos. there no way know whether photos same or different, not url. different photo url same photos created previously. there's no reference id, , not saving/downloading photos in server too.

i have following code:

@shop = shop.find_or_initialize_by(source_id: shop_params[:id]) @shop.photos.build(shop_params[:photos]) 

question

let's when first creat shop a, api returns 4 photos. save 4 photos. call api again shop a, api returns 10 photos. want save these 10 photos. don't mind if previous 4 destroyed or updated. how make work? total photos should 10 after saving.

then, may call api again, returns 6 photos. don't want keep previous 10 photos, 6 photos.

in view, call @shop.photos, latest photos (up 10).

note photos returned api duplicate ones have in db. that's reason why can't keep previous photos.

you can delete previous records , create new photos.

@shop = shop.find_or_initialize_by(source_id: shop_params[:id]) @shop.save_photos(shop_params[:photos]) 

in shop.rb

def save_photos(photos)     self.photos.destroy_all     self.photos.build(photos) end 

it not robust solution work