Is there a way to allow user to vote for multiple proposals. For example: User A can vote for proposals :P1,P2,P3,etc. Once A has voted for P1 he should not be allowed to vote for P1 but is eligible to vote for P2 and P3. I am able to write a contract that shows which proposals the candidate has voted for. Can any one help!!
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Are you talking about Proof of Stake? – Briomkez Sep 19 '18 at 15:24
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Anything is possible! How this can be achieved depends on your implementation, however. Please enlighten us. – Henk Sep 19 '18 at 15:27
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I am unable to devise a logic for it. can anyone help me with that. I have struct for proposal: – aib92 Sep 19 '18 at 15:36
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Oh, I just answered, but forgot to ask if you actually use Solidity. – Utgarda Sep 19 '18 at 15:46
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Yes. I am using solidity – aib92 Sep 19 '18 at 15:53
You can keep users' eligibility to vote for a particular proposal in a structure like
mapping(uint => mapping(address => bool)) hasVoted;
// ^proposal IDs ^users ^already voted or not
mapping(uint => uint) votesCount;
and then check if they are eligible to vote, here's an example in Solidity:
modifier canVote(address user, uint proposal){
require(!hasVoted[proposal][user]);
_;
}
function vote(uint proposal)
public
canVote(msg.sender, proposal) //throw if user has already voted
{
hasVoted[proposal][msg.sender] = true; //make note of the fact he's voting now
votesCount[proposal]++;
//other voting logic you need
}
Take care to use a suitable type for your proposal IDs, like uint8 or whatever is enough.
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if i want to check/allow user to vote for candidate in a proposal then i would have to modify my hasVoted mapping right?? mapping(bytes32 => mapping(bytes32 => mapping(address => bool))) hasVoted;. however the user should be able to vote for candidate in other proposal say P2. – aib92 Sep 19 '18 at 16:20
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Well, naturally, the code should depend on what you want it to do. This example shows just voting for proposals, i.e. how many votes a proposal collects. If voting structure is more complex than that, it probably means you just have to change
votesCountstructure and its use.hasVotedcan stay the same. – Utgarda Sep 19 '18 at 16:24 -
I am sorry to have asked these questions. I am new to programming and solidity – aib92 Sep 19 '18 at 16:25
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No probs, questions is what this sites is all about. Clarifying the above: I think you don't have to alter
hasVoted, because a user can vote for a proposal only once, no matter which candidate he picked ( is that right? ) – Utgarda Sep 19 '18 at 16:26 -
1Yep, for this use case
hasVotedstructure and the modifier in this example stay the same. – Utgarda Sep 19 '18 at 16:32
