blockchain ethereum solidity fund-management fundraiser

Fund Raiser - Homework 1

Contract Requirements Breakdown

CrowdFunding

must include a funding goal
must allow users to contribute to the goal
must identify contributors by their address
may retain other info
must have a state (Unfunded, Prefunded or Funded)
state must be updated when certain conditions are met
contributors may withdraw funds during the Unfunded state
must allow the owner to notify a sponsor
must allow the owner to transfer the funds to a distribution contract when the Funded state is reached

SponsorFunding

must allow sponsoring via percent
must have its own balance
must be able to be initialized with a starting balance
must revert the sponsorship if there are not enough funds
must allow the owner to change the sponsorhip percent
must allow the owner to fund the contract
must verifiy the CrowdFunding contract's balance

DistributeFunding

must allow adding beneficiaries with certain shares
the total shares may amount to less than a hundred
must allow the CrowdFunding to transfer funds
must allow beneficiaries to withdraw their respective shares

Contract Extra Features

Mention: All the functionalities above are implemented and will not be listed again below to make reading easier

BaseFunding

base contract for the following three
comprised of the owner attribute and shared modifiers

CrowdFunding*

status implemented as enum
current funding status returned in string format
both contributors and their respective contributions are retained
custom modifiers created to avoid redundancy and make the code cleaner while enforcing security and strictness
the last contributor is allowed to withdraw its funds if the total balance accumulated exceeds the funding goal
contributors can check their respective contributions
function exposed to receive funds from sponsor
possibility to reset the crowd funding once all the funds have been transferred and the status is Funded

SponsorFunding*

numerous custom modifiers used for enforcing security
allows for choosing between sponsoring with a percentage of the funding goal or the total accumulated balance of the CrowdFunding contract
allows the owner to whitelist certain CrowdFunding contracts
checks the fund requests comes from a whitelisted contract and not an EOA
allows the owner to remove addresses from the whitelist

DistributeFunding*

allows for multiple crowdfundings to use the facilities of the contract by uniquely identifying every CrowdFunding by the address of its owner (referred to as manager below)
each manager only has access to the info that concerns them
the amount gathered by each manager is updated alongside the transfer from the CrowdFunding contract
each manager has a corresponding list of beneficiaries, each with their own respective percentages
total percentages allocated are remembered for each of the managers in order to avoid recalculating them each time a beneficiary is added/updated
beneficiaries can be added by a manager to their mapping
beneficiaries can have their shares updated by a manager
proper fund administration is thouroughly ensured by numerous checks using custom modifiers
beneficiaries can check their respective share
managers can check the amount gathered
managers can check the addresses of the paid beneficiaries

Documentation: All the contracts have been meticulously documented using NatSpec.

Team Members

About

Simulation of a Fund Raiser made up of three components: The Crowd Funding, a Sponsorship Funding and a Distribution mechanism for beneficiaries. Developed for the Introduction to Blockchain Course, part of the Master's Degree in Software Engineering.