Samples

This section contains a collection of ready-to-go samples for common blockchain use cases.

Make an NFT

In Sui, everything is an NFT - Objects are unique, non-fungible, and owned. So technically, a simple type publishing is enough.

module examples::devnet_nft {
    use sui::url::{Self, Url};
    use std::string;
    use sui::object::{Self, ID, UID};
    use sui::event;
    use sui::transfer;
    use sui::tx_context::{Self, TxContext};

    /// An example NFT that can be minted by anybody
    struct DevNetNFT has key, store {
        id: UID,
        /// Name for the token
        name: string::String,
        /// Description of the token
        description: string::String,
        /// URL for the token
        url: Url,
        // TODO: allow custom attributes
    }

    // ===== Events =====

    struct NFTMinted has copy, drop {
        // The Object ID of the NFT
        object_id: ID,
        // The creator of the NFT
        creator: address,
        // The name of the NFT
        name: string::String,
    }

    // ===== Public view functions =====

    /// Get the NFT's `name`
    public fun name(nft: &DevNetNFT): &string::String {
        &nft.name
    }

    /// Get the NFT's `description`
    public fun description(nft: &DevNetNFT): &string::String {
        &nft.description
    }

    /// Get the NFT's `url`
    public fun url(nft: &DevNetNFT): &Url {
        &nft.url
    }

    // ===== Entrypoints =====

    /// Create a new devnet_nft
    public entry fun mint_to_sender(
        name: vector<u8>,
        description: vector<u8>,
        url: vector<u8>,
        ctx: &mut TxContext
    ) {
        let sender = tx_context::sender(ctx);
        let nft = DevNetNFT {
            id: object::new(ctx),
            name: string::utf8(name),
            description: string::utf8(description),
            url: url::new_unsafe_from_bytes(url)
        };

        event::emit(NFTMinted {
            object_id: object::id(&nft),
            creator: sender,
            name: nft.name,
        });

        transfer::transfer(nft, sender);
    }

    /// Transfer `nft` to `recipient`
    public entry fun transfer(
        nft: DevNetNFT, recipient: address, _: &mut TxContext
    ) {
        transfer::transfer(nft, recipient)
    }

    /// Update the `description` of `nft` to `new_description`
    public entry fun update_description(
        nft: &mut DevNetNFT,
        new_description: vector<u8>,
        _: &mut TxContext
    ) {
        nft.description = string::utf8(new_description)
    }

    /// Permanently delete `nft`
    public entry fun burn(nft: DevNetNFT, _: &mut TxContext) {
        let DevNetNFT { id, name: _, description: _, url: _ } = nft;
        object::delete(id)
    }
}

Create a coin

Publishing a coin in Sui is similar to publishing a new type; however, it's a little more complicated as it requires using a One Time Witness.

module examples::mycoin {
    use std::option;
    use sui::coin;
    use sui::transfer;
    use sui::tx_context::{Self, TxContext};

    /// The type identifier of coin. The coin will have a type
    /// tag of kind: `Coin<package_object::mycoin::MYCOIN>`
    /// Make sure that the name of the type matches the module's name.
    struct MYCOIN has drop {}

    /// Module initializer is called once on module publish. A treasury
    /// cap is sent to the publisher, who then controls minting and burning
    fun init(witness: MYCOIN, ctx: &mut TxContext) {
        let (treasury, metadata) = coin::create_currency(witness, 6, b"MYCOIN", b"", b"", option::none(), ctx);
        transfer::freeze_object(metadata);
        transfer::transfer(treasury, tx_context::sender(ctx))
    }
}

The Coin<T> is a generic implementation of a Coin on Sui. Owner of the TreasuryCap gets control over the minting and burning of coins. Further transactions can be sent directly to the sui::coin::Coin with TreasuryCap object as authorization.

Last update 1/13/2023, 10:36:31 PM

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