ERC721 101

Introduction

Welcome! This is an automated workshop that will explain how to deploy an ERC721 token, and customize it to perform specific functions. It is aimed at developpers that have never written code in Solidity, but who understand its syntax.

How to work on this TD

Introduction

The TD has two components:

• An ERC20 token, ticker TD-ERC721-101, that is used to keep track of points
• An evaluator contract, that is able to mint and distribute TD-ERC721-101 points

Your objective is to gather as many TD-ERC721-101 points as possible. Please note :

• The 'transfer' function of TD-ERC721-101 has been disabled to encourage you to finish the TD with only one address
• You can answer the various questions of this workshop with different ERC721 contracts. However, an evaluated address has only one evaluated ERC721 contract at a time. To change the evaluated ERC721 contract associated with your address, call submitExercice() with that specific address.
• In order to receive points, you will have to do execute code in Evaluator.sol such that the function TDERC20.distributeTokens(msg.sender, n); is triggered, and distributes n points.
• This repo contains an interface IExerciceSolution.sol. Your ERC721 contract will have to conform to this interface in order to validate the exercice; that is, your contract needs to implement all the functions described in IExerciceSolution.sol.
• A high level description of what is expected for each exercice is in this readme. A low level description of what is expected can be inferred by reading the code in Evaluator.sol.
• The Evaluator contract sometimes needs to make payments to buy your tokens. Make sure he has enough ETH to do so! If not, you can send ETH directly to the contract.

Getting to work

• Clone the repo on your machine
• Install the required packages npm install truffle, npm install @openzeppelin/[email protected] , npm install @truffle/hdwallet-provider
• Copy the content of example-truffle-config.js to your truffle config
• Configure a seed for deployment of contracts in your truffle config
• Register for an infura key and set it up in your truffle config
• Download and launch Ganache
• Test that you are able to connect to the rinkeby network with truffle console
• Test that you are able to connect to the rinkeby network with truffle console --network rinkeby
• To deploy a contract, configure a migration in the migration folder. Look at the way the TD is deploy and try to iterate
• Test your deployment in Ganache truffle migrate
• Deploy on Rinkeby truffle migrate --network rinkeby --skip-dry-run

Points list

Setting up

• Create a git repository and share it with the teacher
• Install truffle and create an empty truffle project (2 pts). Create an infura API key to be able to deploy to the Rinkeby testnet These points will be attributed manually if you do not manage to have your contract interact with the evaluator, or automatically when calling submitExercice() for the first time.

ERC721 basics

• Create an ERC721 token contract wand give token 1 to Evaluator contract
• Deploy it to the Rinkeby testnet
• Call submitExercice() in the Evaluator to configure the contract you want evaluated (2 pts)
• Call ex1_testERC721() in the evaluator to receive your points (2 pts)
• Call ex2a_getAnimalToCreateAttributes() to get assigned a random creature to create. Mint it and give it to the evaluator
• Call ex2b_testDeclaredAnimal() to receive points (2 pts)
• Create a function to allow breeder registration. Only allow listed breeders should be able to create animals
• Call ex3_testRegisterBreeder() to prove your function works (2pts)

Minting and burning NFTs from contracts

• Create a function to allow breeders to declare animals
• Call ex4_testDeclareAnimal() to get points (2 pts)
• Create a function to allow breeders to declare dead animals
• Call ex5_declareDeadAnimal() to get points (2 pts)

Selling and transferring

• Create a function to offer an animal on sale
• Create a getter for animal sale status and price
• Create a function to buy the animal
• Call ex6a_auctionAnimal_offer() to show your code work (1 pt)
• Call ex6b_auctionAnimal_buy() to show your code work (2 pt)

Mix and match

• The following exercices are in Evaluator2.sol .
• Create a function declareAnimalWithParents() to declare parents of an animal when creating it
• Create a getter to retrieve parents id getParents()
• Call ex7a_breedAnimalWithParents() to get points (1pt)
• Create a function to offer an animal for reproduction, against payment
• Create a getter for animal reproduction status and price
• Call ex7b_offerAnimalForReproduction() to get points (1pt)
• Create a function to pay for reproductive rights
• Call ex7c_payForReproduction() to get points (1pt)

Extra points

Extra points if you find bugs / corrections this TD can benefit from, and submit a PR to make it better. Ideas:

• Adding a way to check the code of a specific contract was only used once (no copying)
• Publish the code of the Evaluator on Etherscan using the "Verify and publish" functionnality

TD addresses

• Points contracts 0x8B7441Cb0449c71B09B96199cCE660635dE49A1D
• Evaluator 0xa0b9f62A0dC5cCc21cfB71BA70070C3E1C66510E
• Evaluator2 0x4f82f7A130821F61931C7675A40fab723b70d1B8

Installing