ExpandedERC20
An ERC20 with permissioned burning and minting. The contract deployer will initially be the owner who is capable of adding new roles.
onlyRoleHolder(uint256 roleId) modifier
Reverts unless the caller is a member of the specified roleId.
onlyRoleManager(uint256 roleId) modifier
Reverts unless the caller is a member of the manager role for the specified roleId.
onlyExclusive(uint256 roleId) modifier
Reverts unless the roleId represents an initialized, exclusive roleId.
onlyShared(uint256 roleId) modifier
Reverts unless the roleId represents an initialized, shared roleId.
constructor(string _tokenName, string _tokenSymbol, uint8 _tokenDecimals) public
Constructs the ExpandedERC20.
Parameters:
-
_tokenName: The name which describes the new token. -
_tokenSymbol: The ticker abbreviation of the name. Ideally < 5 chars. -
_tokenDecimals: The number of decimals to define token precision.
mint(address recipient, uint256 value) → bool external
Mints value tokens to recipient, returning true on success.
Parameters:
-
recipient: address to mint to. -
value: amount of tokens to mint.
burn(uint256 value) external
Burns value tokens owned by msg.sender.
Parameters:
-
value: amount of tokens to burn.
addMinter(address account) external
Add Minter role to account.
The caller must have the Owner role.
Parameters:
-
account: The address to which the Minter role is added.
addBurner(address account) external
Add Burner role to account.
The caller must have the Owner role.
Parameters:
-
account: The address to which the Burner role is added.
resetOwner(address account) external
Reset Owner role to account.
The caller must have the Owner role.
Parameters:
-
account: The new holder of the Owner role.
holdsRole(uint256 roleId, address memberToCheck) → bool public
Whether memberToCheck is a member of roleId.
Reverts if roleId does not correspond to an initialized role.
Parameters:
-
roleId: the Role to check. -
memberToCheck: the address to check.
resetMember(uint256 roleId, address newMember) public
Changes the exclusive role holder of roleId to newMember.
Reverts if the caller is not a member of the managing role for roleId or if roleId is not an
initialized, ExclusiveRole.
Parameters:
-
roleId: the ExclusiveRole membership to modify. -
newMember: the new ExclusiveRole member.
getMember(uint256 roleId) → address public
Gets the current holder of the exclusive role, roleId.
Reverts if roleId does not represent an initialized, exclusive role.
Parameters:
-
roleId: the ExclusiveRole membership to check.
addMember(uint256 roleId, address newMember) public
Adds newMember to the shared role, roleId.
Reverts if roleId does not represent an initialized, SharedRole or if the caller is not a member of the
managing role for roleId.
Parameters:
-
roleId: the SharedRole membership to modify. -
newMember: the new SharedRole member.
removeMember(uint256 roleId, address memberToRemove) public
Removes memberToRemove from the shared role, roleId.
Reverts if roleId does not represent an initialized, SharedRole or if the caller is not a member of the
managing role for roleId.
Parameters:
-
roleId: the SharedRole membership to modify. -
memberToRemove: the current SharedRole member to remove.
renounceMembership(uint256 roleId) public
Removes caller from the role, roleId.
Reverts if the caller is not a member of the role for roleId or if roleId is not an
initialized, SharedRole.
Parameters:
-
roleId: the SharedRole membership to modify.
_createSharedRole(uint256 roleId, uint256 managingRoleId, address[] initialMembers) internal
Internal method to initialize a shared role, roleId, which will be managed by managingRoleId.
initialMembers will be immediately added to the role.
Should be called by derived contracts, usually at construction time. Will revert if the role is already initialized.
_createExclusiveRole(uint256 roleId, uint256 managingRoleId, address initialMember) internal
Internal method to initialize an exclusive role, roleId, which will be managed by managingRoleId.
initialMember will be immediately added to the role.
Should be called by derived contracts, usually at construction time. Will revert if the role is already initialized.
decimals() → uint8 public
Returns the number of decimals used to get its user representation.
For example, if decimals equals 2, a balance of 505 tokens should
be displayed to a user as 5,05 (505 / 10 ** 2).
Tokens usually opt for a value of 18, imitating the relationship between
Ether and Wei. This is the value {ERC20} uses, unless {setupDecimals} is
called.
NOTE: This information is only used for _display purposes: it in
no way affects any of the arithmetic of the contract, including
{IERC20-balanceOf} and {IERC20-transfer}.
transfer(address recipient, uint256 amount) → bool public
See {IERC20-transfer}.
Requirements:
- recipient cannot be the zero address.
- the caller must have a balance of at least amount.
approve(address spender, uint256 amount) → bool public
See {IERC20-approve}.
Requirements:
- spender cannot be the zero address.
transferFrom(address sender, address recipient, uint256 amount) → bool public
See {IERC20-transferFrom}.
Emits an {Approval} event indicating the updated allowance. This is not
required by the EIP. See the note at the beginning of {ERC20};
Requirements:
- sender and recipient cannot be the zero address.
- sender must have a balance of at least amount.
- the caller must have allowance for sender's tokens of at least
amount.
increaseAllowance(address spender, uint256 addedValue) → bool public
Atomically increases the allowance granted to spender by the caller.
This is an alternative to {approve} that can be used as a mitigation for
problems described in {IERC20-approve}.
Emits an {Approval} event indicating the updated allowance.
Requirements:
- spender cannot be the zero address.
decreaseAllowance(address spender, uint256 subtractedValue) → bool public
Atomically decreases the allowance granted to spender by the caller.
This is an alternative to {approve} that can be used as a mitigation for
problems described in {IERC20-approve}.
Emits an {Approval} event indicating the updated allowance.
Requirements:
- spender cannot be the zero address.
- spender must have allowance for the caller of at least
subtractedValue.
_transfer(address sender, address recipient, uint256 amount) internal
Moves tokens amount from sender to recipient.
This is internal function is equivalent to {transfer}, and can be used to
e.g. implement automatic token fees, slashing mechanisms, etc.
Emits a {Transfer} event.
Requirements:
- sender cannot be the zero address.
- recipient cannot be the zero address.
- sender must have a balance of at least amount.
_mint(address account, uint256 amount) internal
Creates amount tokens and assigns them to account, increasing
the total supply.
Emits a {Transfer} event with from set to the zero address.
Requirements
- to cannot be the zero address.
_burn(address account, uint256 amount) internal
Destroys amount tokens from account, reducing the
total supply.
Emits a {Transfer} event with to set to the zero address.
Requirements
- account cannot be the zero address.
- account must have at least amount tokens.
_approve(address owner, address spender, uint256 amount) internal
Sets amount as the allowance of spender over the owner`s tokens.
This is internal function is equivalent to `approve, and can be used to
e.g. set automatic allowances for certain subsystems, etc.
Emits an {Approval} event.
Requirements:
- owner cannot be the zero address.
- spender cannot be the zero address.
setupDecimals(uint8 decimals) internal
Sets {decimals} to a value other than the default one of 18. WARNING: This function should only be called from the constructor. Most applications that interact with token contracts will not expect {decimals} to ever change, and may work incorrectly if it does.
_beforeTokenTransfer(address from, address to, uint256 amount) internal
Hook that is called before any transfer of tokens. This includes
minting and burning.
Calling conditions:
- when from and to are both non-zero, amount of from's tokens
will be to transferred to to.
- when from is zero, amount tokens will be minted for to.
- when to is zero, amount of from's tokens will be burned.
- from and to are never both zero.
To learn more about hooks, head to Using Hooks.