Case study – crowdfunding campaign

In this section, we will implement and deploy the smart contract for the crowdfunding campaign use case.

The idea of crowd funding is a process of raising funds for a project or venture from the masses. Investors receive tokens that represent a share of the startup they invested. The project sets up a predefined goal and a deadline for reaching it. Once a project misses the goal, the investments are returned, which reduces the risk for investors. This decentralized fundraising model can supplant the fund need for startup, and there is no need for a centralized trusted platform. Investors will only pay the gas fees if the fund returns. Any project contributor gets a token, and they can trade, sell, or keep these tokens. In a certain stage, the token can be used in exchange for real products as the physical reward.

Define struct and events, shown as follows:

pragma solidity ^0.4.24;

contract CrowdFunding {

    Project public project;
    Contribution[] public...