Hello, World!

In this smart book we are gonna see one project based on the dao appliactions .

Prerequisites 

• Kowledge of web.js
• Truffle working , Ganache  basic functionality
• metamask
• wallet knowledge 

Introduction

So  there are basically lot's of projects avialable on the internet based on the DAO application . One of them is Voting application that today we are going to see and learn in this blog . 

In that application we have many function like vote particular participant  , see the address of  each participant , count the vote , owner address . 

Let's look on  the smart contarct code and discussed various function and working . 

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.7.0 <0.9.0;

contract vote{
    string public winner;
    address public  participant1 = 0xF6C486B8A4e67b8eff4d5045C804E9be4ed39FF9;
    address public  participant2 = 0xBBDb2A08711D7b2b9c15318E77B6e026eD8fA278;
    mapping(address=>uint) user;
    mapping(address=>bool) chek;

    address public owner;
    constructor(){
        owner = msg.sender;
    }

    modifier onlyonwner(){
        require(msg.sender == owner,"You are not allowed to declare the result");
        _;
    }

    function participant1_vote()  public {
        require(msg.sender !=participant1,"You can not vote to yourself");
        require(chek[msg.sender]!=true,"You have already voted");
        user[participant1]++;
        chek[msg.sender] = true;
    }
        function participant2_vote()  public {
        require(msg.sender !=participant2,"You can not vote to yourself");
        require(chek[msg.sender]!=true,"You have already voted");
        user[participant2]+=1;
        chek[msg.sender] = true;
    }

    function pati1_cnt_VOTE() view public  returns(uint){
        return user[participant1];

    }

    function pati2_cnt_VOTE() view public  returns(uint){
        return user[participant2];

    }

    function declare_winner()  public  onlyonwner {
        if(user[participant1]>user[participant2]){
            winner = "Candidate 1 is winner";
            // winner = _winner;
        }
        else if(user[participant1]==user[participant2]){
            winner = "Draw";
            // winner = _winner;

        }
        else{
            winner = "Candidate 2 is winner";
            // winner = _winner;

        }
    }

}

 About Code 

There is one modifier which is onlyowner that is used to check whether that particular function is called by the owner or not , if not then this will revert the error message . 

• Participant1_vote : This function is usually used to gave votes to the first participant and no one can not give twice vote to any participant . 
•  
• Participant2_vote : This function is same as above . 
• Pati1_cnt_vote : This function is used to count the total vote gained by the participant 1 and it si acessible by all the  member / voter . 
• Pati2_cnt_vote : This function is same as above .
• declare_wineer : This function is only callled by the owner . After the result declared then only the voters see the result . 

Which make's this an application of the DAO as the decalre winner is only called by the owner . 

If u want to make the frontend part   for  this appllication then go through the below link provided. 

Source Code 

1 . Source code 

2 . Video tutorial .