Watafan-issuers.sol

/*
Watafan issuers Smart Contract v1.0
developed by:
	MarketPay.io , 2017
	https://marketpay.io/
	http://lnked.in/blockchain
	
	v1.0 https://gist.github.com/computerphysicslab/5ef16811325fd74fc482bc556b3b9d86
		+ Owner grants new issuers and revokes them too
		+ This is a mortal contract

*/

pragma solidity ^0.4.6;


/*
 * @title Mortal
 *
 * Abstract contract that allows children to implement the functionality of killing the contract and other generic functions.
 *
 */
contract Mortal {
	address owner;
	
	// @notice Constructor sets owner
	function Mortal() { owner = msg.sender; }

	// @notice For debugging purposes when using solidity online browser
	function whoAmI() constant returns (address) {
		return msg.sender;
	}

	// @notice Get the current timestamp from last mined block
	function timestamp() constant returns (uint256) {
		return block.timestamp;
	}
	

	// **** EVENTS

	// @notice A generic error log
	event Error(string error);
	
	// @notice Triggered when owner kills the contract
	event Kill(address killer, uint256 _timestamp);


	// **** MORE FUNCTIONS

	// @notice To limit functions usage to contract owner
	modifier onlyOwner() {
	    if (msg.sender != owner) {
	    	Error('Mortal: onlyOwner function called by user that is not owner');
	    } else {
	    	_;
	    }
	}

	// @notice To kill the contract
	function kill() onlyOwner {
		Kill(msg.sender, timestamp());
		suicide(owner);
	}
}




contract Issuers is Mortal {
	// **** DATA
	
	mapping (address => bool) issuers;


	// **** METHODS


	// Checks whether a given user is an authorized issuer
	function isIssuer(address _issuer) constant returns (bool) {
		return (issuers[_issuer]);
	}
	
	function grantIssuer(address _issuer) external onlyOwner {
		issuers[_issuer] = true;
		GrantIssuer(_issuer, timestamp()); // Event log
	}

	function revokeIssuer(address _issuer) external onlyOwner {
		issuers[_issuer] = false;
		RevokeIssuer(_issuer, timestamp()); // Event log
	}

	// **** EVENTS

	// Triggered when a user is granted to become an issuer
	event GrantIssuer(address who, uint256 _timestamp);
	
	// Triggered when a user is revoked for being an issuer
	event RevokeIssuer(address who, uint256 _timestamp);
}