学习笔记：《Full Stack Blockchain Lesson 3：Remix Storage Factory》

Getting Started Introduction Factory Pattern Basic Solidity: Importing Contracts into other Contracts Composibility Solidity new keyword Importing Code in solidity Basic Solidity: Interacting with other Contracts To interact, you always need: ABI + Address ABI Basic Solidity: Inheritance & Overrides Inheritance Override & Virtual Keyword

Getting Started

Go to Remix

Paste the code from SimpleStorage.sol, StorageFactory.sol, and ExtraStorage.sol into a new file in Remix

Hit Compile

Hit Deploy for whatever contract you want.

SimpleStorage.sol


// SPDX-License-Identifier: MIT

pragma solidity 0.8.8;
// pragma solidity ^0.8.0;
// pragma solidity >=0.8.0 <0.9.0;

contract SimpleStorage {

    uint256 favoriteNumber;

    struct People {
        uint256 favoriteNumber;
        string name;
    }
    // uint256[] public anArray;
    People[] public people;

    mapping(string => uint256) public nameToFavoriteNumber;

    function store(uint256 _favoriteNumber) public virtual {
        favoriteNumber = _favoriteNumber;
    }
    
    function retrieve() public view returns (uint256){
        return favoriteNumber;
    }

    function addPerson(string memory _name, uint256 _favoriteNumber) public {
        people.push(People(_favoriteNumber, _name));
        nameToFavoriteNumber[_name] = _favoriteNumber;
    }
}

StorageFactory.sol


pragma solidity ^0.8.0;

import "./SimpleStorage.sol"; 

contract StorageFactory {
    
    SimpleStorage[] public simpleStorageArray;
    
    function createSimpleStorageContract() public {
        SimpleStorage simpleStorage = new SimpleStorage();
        simpleStorageArray.push(simpleStorage);
    }
    
    function sfStore(uint256 _simpleStorageIndex, uint256 _simpleStorageNumber) public {
        // Address 
        // ABI 
        // SimpleStorage(address(simpleStorageArray[_simpleStorageIndex])).store(_simpleStorageNumber);
        simpleStorageArray[_simpleStorageIndex].store(_simpleStorageNumber);
    }
    
    function sfGet(uint256 _simpleStorageIndex) public view returns (uint256) {
        // return SimpleStorage(address(simpleStorageArray[_simpleStorageIndex])).retrieve();
        return simpleStorageArray[_simpleStorageIndex].retrieve();
    }
}

ExtraStorage.sol


pragma solidity 0.8.8;

import "./SimpleStorage.sol";

contract ExtraStorage is SimpleStorage {
    function store(uint256 _favoriteNumber) public override {
        favoriteNumber = _favoriteNumber + 5;
    }
}

Introduction

Factory Pattern

Basic Solidity: Importing Contracts into other Contracts

Composibility

The ability for contracts to seamlessly interact with each other is what s known as composability.

Solidity new keyword


SimpleStorage public simpleStorage = new simpleStorage();

Importing Code in solidity


// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "./SimpleStorage.sol"

Basic Solidity: Interacting with other Contracts

To interact, you always need: ABI + Address


function sfStore(uint256 _simpleStorageIndex, uint256 _simpleStorageNumber) public {
	// Address
	// ABI - Application Binary Interface 
	simpleStorageArray[_simpleStorageIndex].store(_simpleStorageNumber);
}

function sfGet(uint256 _simpleStorageIndex) public view returns (uint256){
	return simpleStorageArray[_simpleStorageIndex].retrieve();
}

ABI

Basic Solidity: Inheritance & Overrides

Inheritance


// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0

import "./SimpleStorage.sol"

contract ExtraStorage is SimpleStorage {

}

Override & Virtual Keyword

add virtual keyword to the store function that to be override in SimpleStorage.sol


function store(uint256 _favoriteNumber) public virtual {
	favoriteNumber = _favoriteNumber;
}

add override to store function that override


function store(uint256 _favoriteNumber) public override {
	favoriteNumber = _favoriteNumber + 5;
}