Blockchain-attendance-system

A multiple class attendance system on the Blockchain.

Technology Stack

html,css
react
drizzle
truffle
solidity
ganache
web3

Prerequisite

npm - v6.0.0+
node - v14.0.0+

• git clone https://github.com/dynamic-entropy/blockchain-attendance-system.git #clone the project
• cd blockchain-attendance-system # move into project folder
• npm i #to install all dependencies for development

🙏 These commands may take a while, please be patient.

Terminal commands to launch the system

• Run a truffle develop instance
  • truffle develop #starts a local development blockchain
• In the truffle develop console type
  • migrate --reset #to run migrations to deploy the contracts
• (Optionally) run a test
  • test #check if contract were deployed successfully
• In a seperate instance/tab of terminal
  • cd client-app (move into client app, this was bootstrapped with create-react-app)
  • npm start (to start the client-app in development mode)

The DAPP

Every time you use Blockchain to store anything, you have to pay a gas fee. Hence, to reduce the cost paid in gas fee it is assumed that the institution will use a separate database to store the information of students in different classes. Here, we have used a hard coded Database as JSON objects for the same.

    A separate contract is written as well "BLC.sol" where the functionality of adding a class, student and then marking and saving their attendance is also implemented which can be used on Remix IDE but a separate front end is not designed for that contract (cuz money issues). 

• The teacher will be able to mark the attendance on the Blockchain of students present in the database.

• Both teacher and student will be able to see the attendance which was stored on blockchain before.

BLC.sol

This system can directly be used on the Remix. The DB is dynamic and is stored on the Blockchain itself. The teacher can create a class, add students to already created class, mark their presence and retrieve the attendance as well (class wise as well as specific student wise)

Structures used

Student structure : Contains id, name and presence of each student
Attendance List structure: Contains id and presence on that day

Mappings used and their functionality

ClassRollMap : Class -> Max Students #Keeps a track of total students in that class
School : Class -> Student_id -> Student_info #The database which can be stored on the Blockchain containing info of all students
allRecord : Class -> Date -> Student info array with presence #Maintains the attendance record of each class separately.
studentRecord : Class -> Student_id -> AttendanceList array #Maintains the attendance record of each student separately.

Functions

createClass : Create a new class.
addStudent : Inputs the class name and add student to that class.
MarkPresent : Inputs classs name and student_id to mark the presence of the given student.
MarkAbsent : Inputs classs name and student_id to mark the absence of the given student.
getRecord : Get the whole  record of a class after inputting class and date.
getStudentRecord : Get the whole previous record of a student's attendance after inputting class and student_id.
Percentage : Input the class and student_id, this function can calculate the percentage of classes attended by that student.