Impossible to count number of NFTs in large collections and get the IDs

[cybercent]

Issue to be solved

getIDs().length breaks when used on accounts with large NFT collections like 0x329feb3ab062d289.661249

failed to retrieve slab 0x329feb3ab062d289.661249: get value failed: [Error Code: 1110] computation exceeds limit (100000)

Suggested Solution

• Add way to get the count of total NFTs by avoiding getIDs().length
• Add way to get a slice of the IDs in the collection.

@joshuahannan I'm tagging you here as this might be interesting for the V2 standard.

[joshuahannan]

yeah I would love if we could find a solution for this that we could use with the standard

[turbolent]

These improvements are all related to the NFT standard, moving

[austinkline]

Can this be done with what we have currently? I'd guess we might have to tackle it with the V2 standards coming out with stable cadence. The main issue as I understand it is that getIDs has to load all IDs into memory which is just too costly for large collections

[turbolent]

To allow users to query the size of the collection, Collection should provide a getter function for it, so that users do not need to rely on the inefficient getIDs().length.

This is simple by adding:

fun getCount(): Int
    return ownedNFTs.length
}

[cybercent]

Looks good for getting ID count, any idea on getting a slice of the IDs without loading all of them with getIDs ?

Maybe a function to return:

ownedNFTs.slice(from: upTo:) , loop through them get the IDs and return them

[joshuahannan]

Yeah, I think getting a slice like that will require an update to Cadence

I added getLength to the new standard btw

[bjartek]

You could do iteration over the map and fetch the first x ones?

[joshuahannan]

getLength addresses this so I am closing