ERC-721 Metadata
Extension of ERC-721 that adds the optional metadata functions from the ERC721 standard.
Usage
In order to make ERC-721 Metadata
methods “external” so that other contracts can call them, you need to add the following code to your contract:
use openzeppelin_stylus::{
token::erc721::{
self,
extensions::{Erc721Metadata, IErc721Metadata },
Erc721, IErc721,
},
utils::introspection::erc165::IErc165,
};
#[entrypoint]
#[storage]
struct Erc721MetadataExample {
erc721: Erc721,
metadata: Erc721Metadata,
}
#[public]
#[implements(IErc721<Error = erc721::Error>, IErc721Metadata<Error = erc721::Error>, IErc165)]
impl Erc721MetadataExample {
#[constructor]
fn constructor(&mut self, name: String, symbol: String, base_uri: String) {
self.metadata.constructor(name, symbol);
self.metadata.base_uri.set_str(base_uri);
}
fn mint(
&mut self,
to: Address,
token_id: U256,
) -> Result<(), erc721::Error> {
self.erc721._mint(to, token_id)
}
}
#[public]
impl IErc721 for Erc721MetadataExample {
type Error = erc721::Error;
fn balance_of(&self, owner: Address) -> Result<U256, Self::Error> {
self.erc721.balance_of(owner)
}
fn owner_of(&self, token_id: U256) -> Result<Address, Self::Error> {
self.erc721.owner_of(token_id)
}
fn safe_transfer_from(
&mut self,
from: Address,
to: Address,
token_id: U256,
) -> Result<(), Self::Error> {
self.erc721.safe_transfer_from(from, to, token_id)
}
fn safe_transfer_from_with_data(
&mut self,
from: Address,
to: Address,
token_id: U256,
data: Bytes,
) -> Result<(), Self::Error> {
self.erc721.safe_transfer_from_with_data(from, to, token_id, data)
}
fn transfer_from(
&mut self,
from: Address,
to: Address,
token_id: U256,
) -> Result<(), Self::Error> {
self.erc721.transfer_from(from, to, token_id)
}
fn approve(
&mut self,
to: Address,
token_id: U256,
) -> Result<(), Self::Error> {
self.erc721.approve(to, token_id)
}
fn set_approval_for_all(
&mut self,
to: Address,
approved: bool,
) -> Result<(), Self::Error> {
self.erc721.set_approval_for_all(to, approved)
}
fn get_approved(&self, token_id: U256) -> Result<Address, Self::Error> {
self.erc721.get_approved(token_id)
}
fn is_approved_for_all(&self, owner: Address, operator: Address) -> bool {
self.erc721.is_approved_for_all(owner, operator)
}
}
#[public]
impl IErc721Metadata for Erc721MetadataExample {
type Error = erc721::Error;
fn name(&self) -> String {
self.metadata.name()
}
fn symbol(&self) -> String {
self.metadata.symbol()
}
#[selector(name = "tokenURI")]
fn token_uri(&self, token_id: U256) -> Result<String, Self::Error> {
self.metadata.token_uri(token_id, &self.erc721)
}
}
#[public]
impl IErc165 for Erc721MetadataExample {
fn supports_interface(&self, interface_id: FixedBytes<4>) -> bool {
self.erc721.supports_interface(interface_id)
|| <Self as IErc721Metadata>::interface_id() == interface_id
}
}