Stats
Public Functions
21
Event Types
4
Code Size
137,076 bytes
Events (4)
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Approval
Event
Parameters
help
Event parameters list the data that an event contains.
owner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
approved |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
ApprovalForAll
Event
Parameters
help
Event parameters list the data that an event contains.
owner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
operator |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
approved |
bool help
The type of this value is other.
|
OwnershipTransferred
Event
Parameters
help
Event parameters list the data that an event contains.
previousOwner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
newOwner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
Transfer
Event
Parameters
help
Event parameters list the data that an event contains.
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Constants (5)
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_ERC721_RECEIVED
Constant
bytes4
help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
0x150b7a02
_INTERFACE_ID_ERC721
Constant
bytes4
help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
0x80ac58cd
_INTERFACE_ID_ERC721_METADATA
Constant
bytes4
help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
0x5b5e139f
_INTERFACE_ID_ERC721_ENUMERABLE
Constant
bytes4
help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
0x780e9d63
_INTERFACE_ID_ERC165
Constant
bytes4
help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
0x01ffc9a7
State Variables (10)
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_holderTokens
Variable
mapping(address => EnumerableSet.UintSet)
help
The type of this value is other.
_tokenOwners
Variable
EnumerableMap.UintToAddressMap
help
The type of this value is other.
_tokenApprovals
Variable
mapping(uint256 => address)
help
The type of this value is other.
_operatorApprovals
Variable
mapping(address => mapping(address => bool))
help
The type of this value is other.
_name
Variable
string
help
The type of this value is string, which is basically just plain text. It's called a string because it is a 'string' of letters.
_symbol
Variable
string
help
The type of this value is string, which is basically just plain text. It's called a string because it is a 'string' of letters.
_tokenURIs
Variable
mapping(uint256 => string)
help
The type of this value is other.
_baseURI
Variable
string
help
The type of this value is string, which is basically just plain text. It's called a string because it is a 'string' of letters.
_supportedInterfaces
Variable
mapping(bytes4 => bool)
help
The type of this value is other.
_owner
Variable
address
help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
owner
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function owner() public view returns (address) {
return _owner;
}
renounceOwnership
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Modifiers
help
Modifiers are additions to a function that typically make various checks before
the function is run.
onlyOwner
checks for the following:
Source Code
function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
transferOwnership
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
newOwner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Modifiers
help
Modifiers are additions to a function that typically make various checks before
the function is run.
onlyOwner
checks for the following:
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
supportsInterface
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
interfaceId |
bytes4 help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function supportsInterface(bytes4 interfaceId)
public
view
override
returns (bool)
{
return _supportedInterfaces[interfaceId];
}
balanceOf
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
owner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function balanceOf(address owner) public view override returns (uint256) {
require(owner != address(0), "ERC721: balance query for the zero address");
return _holderTokens[owner].length();
}
ownerOf
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function ownerOf(uint256 tokenId) public view override returns (address) {
return _tokenOwners.get(tokenId, "ERC721: owner query for nonexistent token");
}
name
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function name() public view override returns (string memory) {
return _name;
}
symbol
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function symbol() public view override returns (string memory) {
return _symbol;
}
tokenURI
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function tokenURI(uint256 tokenId)
public
view
override
returns (string memory)
{
require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
string memory _tokenURI = _tokenURIs[tokenId];
// If there is no base URI, return the token URI.
if (bytes(_baseURI).length == 0) {
return _tokenURI;
}
// If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
if (bytes(_tokenURI).length > 0) {
return string(abi.encodePacked(_baseURI, _tokenURI));
}
// If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
return string(abi.encodePacked(_baseURI, tokenId.toString()));
}
baseURI
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function baseURI() public view returns (string memory) {
return _baseURI;
}
tokenOfOwnerByIndex
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
owner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
index |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function tokenOfOwnerByIndex(address owner, uint256 index)
public
view
override
returns (uint256)
{
return _holderTokens[owner].at(index);
}
totalSupply
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function totalSupply() public view override returns (uint256) {
// _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds
return _tokenOwners.length();
}
tokenByIndex
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
index |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function tokenByIndex(uint256 index) public view override returns (uint256) {
(uint256 tokenId, ) = _tokenOwners.at(index);
return tokenId;
}
approve
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function approve(address to, uint256 tokenId) public virtual override {
address owner = ownerOf(tokenId);
require(to != owner, "ERC721: approval to current owner");
require(
_msgSender() == owner || isApprovedForAll(owner, _msgSender()),
"ERC721: approve caller is not owner nor approved for all"
);
_approve(to, tokenId);
}
getApproved
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function getApproved(uint256 tokenId) public view override returns (address) {
require(_exists(tokenId), "ERC721: approved query for nonexistent token");
return _tokenApprovals[tokenId];
}
setApprovalForAll
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
operator |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
approved |
bool help
The type of this value is other.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function setApprovalForAll(address operator, bool approved)
public
virtual
override
{
require(operator != _msgSender(), "ERC721: approve to caller");
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
isApprovedForAll
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
owner |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
operator |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function isApprovedForAll(address owner, address operator)
public
view
override
returns (bool)
{
return _operatorApprovals[owner][operator];
}
transferFrom
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function transferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
//solhint-disable-next-line max-line-length
require(
_isApprovedOrOwner(_msgSender(), tokenId),
"ERC721: transfer caller is not owner nor approved"
);
_transfer(from, to, tokenId);
}
safeTransferFrom
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public virtual override {
safeTransferFrom(from, to, tokenId, "");
}
safeTransferFrom
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
_data |
bytes help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes memory _data
) public virtual override {
require(
_isApprovedOrOwner(_msgSender(), tokenId),
"ERC721: transfer caller is not owner nor approved"
);
_safeTransfer(from, to, tokenId, _data);
}
mint
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
_tokenURI |
string help
The type of this value is string, which is basically just plain text. It's called a string because it is a 'string' of letters.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
public
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Modifiers
help
Modifiers are additions to a function that typically make various checks before
the function is run.
onlyOwner
checks for the following:
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function mint(
address to,
uint256 tokenId,
string memory _tokenURI
) public onlyOwner {
_mint(to, tokenId);
_setTokenURI(tokenId, _tokenURI);
}
Internal functions are parts of the contract that can't be used directly, but instead are used by
the public functions listed above.
internal ERC721._safeTransfer
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
_data |
bytes help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _safeTransfer(
address from,
address to,
uint256 tokenId,
bytes memory _data
) internal virtual {
_transfer(from, to, tokenId);
require(
_checkOnERC721Received(from, to, tokenId, _data),
"ERC721: transfer to non ERC721Receiver implementer"
);
}
internal ERC721._exists
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function _exists(uint256 tokenId) internal view returns (bool) {
return _tokenOwners.contains(tokenId);
}
internal ERC721._isApprovedOrOwner
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
spender |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _isApprovedOrOwner(address spender, uint256 tokenId)
internal
view
returns (bool)
{
require(_exists(tokenId), "ERC721: operator query for nonexistent token");
address owner = ownerOf(tokenId);
return (spender == owner ||
getApproved(tokenId) == spender ||
isApprovedForAll(owner, spender));
}
internal ERC721._safeMint
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _safeMint(address to, uint256 tokenId) internal virtual {
_safeMint(to, tokenId, "");
}
internal ERC721._safeMint
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
_data |
bytes help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _safeMint(
address to,
uint256 tokenId,
bytes memory _data
) internal virtual {
_mint(to, tokenId);
require(
_checkOnERC721Received(address(0), to, tokenId, _data),
"ERC721: transfer to non ERC721Receiver implementer"
);
}
internal ERC721._mint
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _mint(address to, uint256 tokenId) internal virtual {
require(to != address(0), "ERC721: mint to the zero address");
require(!_exists(tokenId), "ERC721: token already minted");
_beforeTokenTransfer(address(0), to, tokenId);
_holderTokens[to].add(tokenId);
_tokenOwners.set(tokenId, to);
emit Transfer(address(0), to, tokenId);
}
internal ERC721._burn
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Source Code
function _burn(uint256 tokenId) internal virtual {
address owner = ownerOf(tokenId);
_beforeTokenTransfer(owner, address(0), tokenId);
// Clear approvals
_approve(address(0), tokenId);
// Clear metadata (if any)
if (bytes(_tokenURIs[tokenId]).length != 0) {
delete _tokenURIs[tokenId];
}
_holderTokens[owner].remove(tokenId);
_tokenOwners.remove(tokenId);
emit Transfer(owner, address(0), tokenId);
}
internal ERC721._transfer
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _transfer(
address from,
address to,
uint256 tokenId
) internal virtual {
require(
ownerOf(tokenId) == from,
"ERC721: transfer of token that is not own"
);
require(to != address(0), "ERC721: transfer to the zero address");
_beforeTokenTransfer(from, to, tokenId);
// Clear approvals from the previous owner
_approve(address(0), tokenId);
_holderTokens[from].remove(tokenId);
_holderTokens[to].add(tokenId);
_tokenOwners.set(tokenId, to);
emit Transfer(from, to, tokenId);
}
internal ERC721._setTokenURI
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
_tokenURI |
string help
The type of this value is string, which is basically just plain text. It's called a string because it is a 'string' of letters.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _setTokenURI(uint256 tokenId, string memory _tokenURI)
internal
virtual
{
require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
_tokenURIs[tokenId] = _tokenURI;
}
internal ERC721._setBaseURI
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
baseURI_ |
string help
The type of this value is string, which is basically just plain text. It's called a string because it is a 'string' of letters.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Source Code
function _setBaseURI(string memory baseURI_) internal virtual {
_baseURI = baseURI_;
}
internal ERC721._checkOnERC721Received
keyboard_arrow_up
Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
_data |
bytes help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
private
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Source Code
function _checkOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory _data
) private returns (bool) {
if (!to.isContract()) {
return true;
}
bytes memory returndata = to.functionCall(
abi.encodeWithSelector(
IERC721Receiver(to).onERC721Received.selector,
_msgSender(),
from,
tokenId,
_data
),
"ERC721: transfer to non ERC721Receiver implementer"
);
bytes4 retval = abi.decode(returndata, (bytes4));
return (retval == _ERC721_RECEIVED);
}
internal ERC721._approve
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
private
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Source Code
function _approve(address to, uint256 tokenId) private {
_tokenApprovals[tokenId] = to;
emit Approval(ownerOf(tokenId), to, tokenId);
}
internal ERC721._beforeTokenTransfer
keyboard_arrow_up
Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
from |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
to |
address help
The type of this value is address, which means it stores an Ethereum address, such as a wallet address.
|
tokenId |
uint256 help
The type of this value is uint, which stands for unsigned integer. Integer means it's a whole number (such as 1, 12, 52) without fractions or decimals. Unsigned means it can't have a negative or positive sign, so it's always a positive number.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Source Code
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual {}
internal Context._msgSender
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function _msgSender() internal view virtual returns (address payable) {
return msg.sender;
}
internal Context._msgData
keyboard_arrow_up
Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
internal ERC165.constructor
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
constructor() internal {
// Derived contracts need only register support for their own interfaces,
// we register support for ERC165 itself here
_registerInterface(_INTERFACE_ID_ERC165);
}
internal ERC165._registerInterface
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
Name |
Type |
interfaceId |
bytes4 help
The type of this value is byte or bytes. Byte data is usually not intended for human reading, and stores binary data.
|
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Requirements
help
Requirements are checks that the function makes when it runs, and give you
insight on what conditions are required for the function to succeed.
Source Code
function _registerInterface(bytes4 interfaceId) internal virtual {
require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
_supportedInterfaces[interfaceId] = true;
}
internal Ownable.constructor
keyboard_arrow_up
Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
transaction
Source Code
constructor() internal {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
internal Context._msgSender
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Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function _msgSender() internal view virtual returns (address payable) {
return msg.sender;
}
internal Context._msgData
keyboard_arrow_up
Parameters
help
Function parameters list what input the function expects from the user. Each
parameter must be given a value.
This function has no parameters.
Properties
Visibility
help
Visibility determines if the function is visible to users and other contracts.
Only functions that are public can be used.
internal
Mutability
help
Mutability tells you if a function can make changes on the blockchain.
View means the function can be called by anyone without
a wallet and without submitting a transaction.
view
Source Code
function _msgData() internal view virtual returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}