VRHToken.md

Virtual Rehab Token (VRH) ERC20 Token Contract (VRHToken.sol)

contract VRHToken is StandardToken, CustomPausable, BurnableToken

VRHToken

The Virtual Rehab Token (VRH) has been created as a centralized currency to be used within the Virtual Rehab network. Users will be able to purchase and sell VRH tokens in exchanges. The token follows the standards of Ethereum ERC20 Standard token. Its design follows the widely adopted token implementation standards. This allows token holders to easily store and manage their VRH tokens using existing solutions including ERC20-compatible Ethereum wallets. The VRH Token is a utility token and is core to Virtual Rehab’s end-to-end operations.

///VRH utility use cases include:

1. Order & Download Virtual Rehab programs through the Virtual Rehab Online Portal
2. Request further analysis, conducted by Virtual Rehab's unique expert system (which leverages Artificial Intelligence), of the executed programs
3. Receive incentives (VRH rewards) for seeking help and counselling from psychologists, therapists, or medical doctors
4. Allows users to pay for services received at the Virtual Rehab Therapy Center

Contract Members

Constants & Variables

//public members
uint8 public constant decimals;
string public constant name;
string public constant symbol;
uint256 public constant MAX_SUPPLY;
uint256 public constant INITIAL_SUPPLY;
bool public released;
uint256 public ICOEndDate;

//private members
mapping(bytes32 => bool) private mintingList;

Events

event Mint(address indexed to, uint256 amount);
event BulkTransferPerformed(address[] _destinations, uint256[] _amounts);
event TokenReleased(bool _state);
event ICOEndDateSet(uint256 _date);

Modifiers

• canTransfer
• whenNotMinted

canTransfer

Checks if the supplied address is able to perform transfers.

modifier canTransfer(address _from) internal

Arguments

Name	Type	Description
_from	address	The address to check against if the transfer is allowed.

whenNotMinted

Checks if the minting for the supplied key was already performed.

modifier whenNotMinted(string _key) internal

Arguments

Name	Type	Description
_key	string	The key or category name of minting.

Functions

• computeHash
• releaseTokenForTransfer
• disableTokenTransfers
• setICOEndDate
• mintTokens
• mintOnce
• mintTokensForAdvisors
• mintTokensForFounders
• mintTokensForServices
• transfer
• transferFrom
• approve
• increaseApproval
• decreaseApproval
• sumOf
• bulkTransfer
• burn

computeHash

Computes keccak256 hash of the supplied value.

function computeHash(string _key) private pure
returns(bytes32)

Arguments

Name	Type	Description
_key	string	The string value to compute hash from.

releaseTokenForTransfer

This function enables token transfers for everyone. Can only be enabled after the end of the ICO.

function releaseTokenForTransfer() public onlyAdmin whenNotPaused

disableTokenTransfers

This function disables token transfers for everyone.

function disableTokenTransfers() public onlyAdmin whenNotPaused

setICOEndDate

This function enables the whitelisted application (internal application) to set the ICO end date and can only be used once.

function setICOEndDate(uint256 _date) public onlyAdmin

Arguments

Name	Type	Description
_date	uint256	The date to set as the ICO end date.

mintTokens

function mintTokens(address _to, uint256 _value) private

Arguments

Name	Type	Description
_to	address	The address which will receive the minted tokens.
_value	uint256	The amount of tokens to mint.

mintOnce

Mints the tokens only once against the supplied key (category).

function mintOnce(string _key, address _to, uint256 _amount) private whenNotPaused whenNotMinted

Arguments

Name	Type	Description
_key	string	The key or the category of the allocation to mint the tokens for.
_to	address	The address receiving the minted tokens.
_amount	uint256	The amount of tokens to mint.

mintTokensForAdvisors

Mints the below-mentioned amount of tokens allocated to the Virtual Rehab advisors.

function mintTokensForAdvisors() public onlyAdmin

mintTokensForFounders

Mints the below-mentioned amount of tokens allocated to the Virtual Rehab founders.

function mintTokensForFounders() public onlyAdmin

mintTokensForServices

Mints the below-mentioned amount of tokens allocated to Virtual Rehab services.

function mintTokensForServices() public onlyAdmin

transfer

🔺 overrides BasicToken.transfer

function transfer(address _to, uint256 _value) public canTransfer
returns(bool)

Arguments

Name	Type	Description
_to	address	The destination wallet address to transfer funds to.
_value	uint256	The amount of tokens to send to the destination address.

transferFrom

🔺 overrides StandardToken.transferFrom

Transfers tokens from a specified wallet address.

function transferFrom(address _from, address _to, uint256 _value) public canTransfer
returns(bool)

Arguments

Name	Type	Description
_from	address	The address to transfer funds from.
_to	address	The address to transfer funds to.
_value	uint256	The amount of tokens to transfer.

approve

🔺 overrides StandardToken.approve

Approves a wallet address to spend on behalf of the sender.

function approve(address _spender, uint256 _value) public canTransfer
returns(bool)

Arguments

Name	Type	Description
_spender	address	The address which is approved to spend on behalf of the sender.
_value	uint256	The amount of tokens approve to spend.

increaseApproval

🔺 overrides StandardToken.increaseApproval

Increases the approval of the spender.

function increaseApproval(address _spender, uint256 _addedValue) public canTransfer
returns(bool)

Arguments

Name	Type	Description
_spender	address	The address which is approved to spend on behalf of the sender.
_addedValue	uint256	The added amount of tokens approved to spend.

decreaseApproval

🔺 overrides StandardToken.decreaseApproval

Decreases the approval of the spender.

function decreaseApproval(address _spender, uint256 _subtractedValue) public canTransfer
returns(bool)

Arguments

Name	Type	Description
_spender	address	The address of the spender to decrease the allocation from.
_subtractedValue	uint256	The amount of tokens to subtract from the approved allocation.

sumOf

Returns the sum of supplied values.

function sumOf(uint256[] _values) private pure
returns(uint256)

Arguments

Name	Type	Description
_values	uint256[]	The collection of values to create the sum from.

bulkTransfer

Allows only the admins and/or whitelisted applications to perform bulk transfer operation.

function bulkTransfer(address[] _destinations, uint256[] _amounts) public onlyAdmin

Arguments

Name	Type	Description
_destinations	address[]	The destination wallet addresses to send funds to.
_amounts	uint256[]	The respective amount of fund to send to the specified addresses.

burn

🔺 overrides BurnableToken.burn

Burns the coins held by the sender.

function burn(uint256 _value) public whenNotPaused

Arguments

Name	Type	Description
_value	uint256	The amount of coins to burn.

Contracts

• ERC20Basic
• SafeMath
• BasicToken
• StandardToken
• CustomPausable
• BurnableToken
• CustomAdmin
• Migrations
• Ownable
• ERC20
• VRHToken