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Questions tagged [erc-721]

Relating to ERC-721, the standard for Non-Fungible Tokens (also known as Deeds)

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ERC721 Token - Burn and mint again

I didn't try yet, but let's suppose the following: I have an ERC721 contract token with a total Supply of 101 My contract can mint and burn The first token has id 0 and the last one has id 100 I burned the token with id 50. Can I mint again the…
Giuseppe
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Store ERC721 token metadata

I am new to ERC721 tokens so this may be a stupid question. I want to create my own ERC721 which can be integrated with opensea using the metadata, as far as I understand you have to store the tokenUri which is an HTTP link in a server or using…
strangethingspy
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How can there be a balance for an ERC721 contract?

Look at this implementation, I can see that ERC721 contracts keep track of an owner (identified by its address) for each single token (identified by its token ID, a 256 bit number): mapping (uint256 => address) internal tokenOwner; So when there's…
Capn Sparrow
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What is the difference between approval and ownership in ERC721?

I saw the contract as getApproved and ownerOf functions. What is the difference between owning the token under ERC721 and having approval? When the tokenid is transferred does that transfer ownership or approval? /** * @dev Gets the approved…
Trevor Lee Oakley
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Can erc721 belong to another erc721 token?

I learnt somewhere today that an erc721 token doesn't have to belong to an account, it could belong to another erc721! How can this be implemented? where can I read more of this? Thanks
Zhen Liu
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ERC standard: possible to set upper price limit for NFT?

Let's say I want to create a non-fungible token which represents a ticket to a venue. And I don't want ticket scalpers to buy tickets and resell these tickets for a higher price. It should only be possible to resell the ticket for the same or a…
Simon Bachmann
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Bitwise XOR used as signature

In a sample ERC721 contract linked from a loom-network medium post, I saw this code: bytes4 constant InterfaceSignature_ERC721 = bytes4(keccak256('name()')) ^ bytes4(keccak256('symbol()')) ^ bytes4(keccak256('totalSupply()')) ^ …
bee
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ERC721 Metadata Creation (Newbie Question)

Complete newbie here so thanks in advance for tolerating the ignorance that follows. Working on creating a little card game to learn solidity and have reached the part where I need to assign metadata to the token. I understand that the tokenURI…
Kevin Phillips
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How are ERC-721 protocol tokens different from Ardor assets? Is there a pro/con data sheet?

ERC-721 protocol is used to create unique tokens like crypto kitties, but I'm curious has anyone compared it to the Ardor Ignis singleton assets as it seems like it does something similar. Is there a pro/cons data sheet?
Patoshi パトシ
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What Are Good Specific Reasons The onERC721Received Function Returns A Magic Value?

The ERC721 standard says the following: The onERC721Received function specifically works around old deployed contracts which may inadvertently return 1 (true) in certain circumstances even if they don't implement a function (see Solidity…
mudgen
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erc721 token uniqueness

I am doing research on using the erc721 interface to represent a digital good on an exchange. For simplicity's sake, let's say that these goods are a digital representation of a collectible card game (e.g. Magic the Gathering). It is my…
Soliditer
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ERC721 Token unique string

I am trying to understand how to use the ERC721 token. I want to change the function mint with a parameter of type uint256 to the parameter of type string and create a unique string, it's possible to replace uint256 tokenid to string…
Ron Berreby
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How exactly is ERC721 tokens non-fungible?

What makes them unique as compared to the ERC20? Is it the owner's address as included in the form of token id? So what makes them unique is the historical chain of addresses attached to it?
Danny
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ERC721 - getting the list of all token owners (all addresses)

I have an ERC721 compliant contract with multiple NFT tokens. I'm looking for a way to randomly select one of the token owners. Is there a way to get the current list or all token owners from ERC721 or do I need to create the mapping myself? If…
marteenas
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Avoiding async minting errors

Im learning Solidity and I found an ERC721 contract that seems to have a very dangerous minting process. Am I correct in assuming that if User_a tries to mint 20 at the exact same time as User_b tries to mint 20, one of the transactions could fail…
farlord
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