Multiple Metadata Views

01 Apr 2022

Contributed by Flow Blockchain

Intermediate

Have more views you want to create for metadata? This is how you create new views in your smart contract and how you execute a transaction to display them all.

Smart Contract Example

//Structure created so that a traits view can be displayed
pub struct Traits{
    pub let power: String
    pub let will: String
    pub let determination: String


    init(
        power: String
        will: String
        determination: String
    ){
        self.power=power
        self.will=will
        self.determination=determination
    }
}

//NFT resources
pub resource NFT: NonFungibleToken.INFT, MetadataViews.Resolver {
    pub let id: UInt64

    pub let name: String
    pub let thumbnail: String
    pub let description: String
    pub let power: String
    pub let will: String
    pub let determination: String


    pub fun getViews(): [Type] {
        return [
            Type<MetadataViews.Display>(),
            Type<NewExampleNFT.Traits>()
        ]
    }

    pub fun resolveView(_ view: Type): AnyStruct? {
        switch view {
            case Type<MetadataViews.Display>():
                return MetadataViews.Display(
                    name: self.name,
                    description: self.description,
                    thumbnail: self.thumbnail
                )
            case Type<NewExampleNFT.Traits>():
                return NewExampleNFT.Traits(
                    power: self.power,
                    will: self.will,
                    determination: self.determination
                )
        }

        return nil
    }

    init(
        id: UInt64,
        name: String,
        description: String,
        thumbnail: String,
        power: String,
        will: String,
        determination: String
    ) {
        self.id = id
        self.name = name
        self.thumbnail = thumbnail
        self.description = description
        self.power = power
        self.will = will
        self.determination= determination
    }
}

To have more than just the display view, you can create your own Struct in your contract so that it may be used as a view in your NFT.

Here we create a Traits structure. We then include the Traits view in the getViews function as well as include it as an option in the resolve view function.

Transaction Example

import MetadataViews from 0x01
import NewExampleNFT from 0x02

pub fun main(): AnyStruct {
    let address: Address = 0x02
    let id: UInt64 = 0
    
    let account = getAccount(address)

    let collection = account
        .getCapability(/public/exampleNFTCollection)
        .borrow<&{MetadataViews.ResolverCollection}>()
        ?? panic("Could not borrow a reference to the collection")

    let nft = collection.borrowViewResolver(id: id)


    // Get the basic display information for this NFT
    

    let view = nft.resolveView(Type<NewExampleNFT.Traits>())
    let oview = nft.resolveView(Type<MetadataViews.Display>())

    let object = {"Traits": view, "Display": oview}

    return object
}

Now, just as we did with the Display view, we resolve the view for the Traits view and can return it as a dictionary, or however you choose.

Now we have both views and metadata available with very little code needed.

ProgressNFT Fundamentals

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