amend

nft.mediawiki

@@ -19,104 +19,145 @@ NFTs are required to track, exchange and enforce ownership of digital assets. A
 
 ===Methods===
 
-====balanceOf====
+====name====
+
 <pre>
-public static BigInteger balanceOf(byte[] owner)
+public static string name()
 </pre>
-Returns current total tokens owned by <code>owner</code>.
 
-====circulation====
+Returns the name of the token. e.g. <code>"MyNFT"</code>. 
+
+This method MUST always return the same value every time it is invoked. 
+
+====symbol====
 
 <pre>
-public static BigInteger circulation()
+public static string symbol()
 </pre>
+
+Returns a short string symbol of the token managed in this contract. e.g. <code>"MNFT"</code>. This symbol SHOULD be short (3-8 characters is recommended), with no whitespace characters or new-lines and SHOULD be limited to the uppercase latin alphabet (i.e. the 26 letters used in English). 
+
+This method MUST always return the same value every time it is invoked. 
+
+====totalSupply====
+
+<pre>
+public static BigInteger totalSupply()
+</pre>
+
 Returns the total token supply deployed in the system.
 
 ====decimals====
+
 <pre>
 public static byte decimals()
 </pre>
-Returns the number of decimals of tokens in the system.
 
-====mintToken====
-<pre>
-public static bool mintToken(byte[] owner, byte[] ROData, byte[] RWData, string URI)
-</pre>
-Creates a new non-fungible token. This fails and returns <code>False</code> if <code>owner</code> is not the contract owner.
+Returns the number of decimals used by the token - e.g. <code>8</code>, means to divide the token amount by <code>100,000,000</code> to get its user representation.
 
+If the token managed in this contract is indivisible, the function SHOULD return <code>0</code>.
 
-====modifyRWData====
-<pre>
-public static bool modifyRWData(byte[] tokenid, byte[] RWData)
-</pre>
-Modifies a token's read/write data. This fails and returns <code>False</code> if <code>owner</code> is not the contract owner. Read-write data represents data that can be changed in the token, i.e., the owner of a property or work of art.
+If the function returns a non-zero value, all of the ''OPTIONAL'' methods in this standard MUST be implemented.
 
-====modifyURI====
-<pre>
-public static bool modifyURI(byte[] tokenid, string URI)
-</pre>
-Modifies a token's URI. This fails and returns <code>False</code> if <code>owner</code> is not the contract owner. The URI data of a token supplies a reference to get more information about a specific token or its data.
+This method MUST always return the same value every time it is invoked. 
 
-====name====
-<pre>
-public static string name()
-</pre>
-Returns the name of the token.
+====tokens====
 
-====ownerOf====
 <pre>
-public static byte[] ownerOf(byte[] tokenid)
+public static enumerator tokens()
 </pre>
-Returns the owner of token with id <code>tokenid</code>.
 
-====symbol====
-<pre>
-public static string symbol()
-</pre>
-Returns the token symbol.
+Returns an <code>enumerator</code> that contains all the tokens that have been issued in this contract.
+
+====transfer====
 
-====tokenOfOwnerByIndex====
 <pre>
-public static byte[] tokenOfOwnerByIndex(byte[] owner, int idx)
+public static bool transfer(byte[] to, byte[] tokenid)
 </pre>
-Returns the token owned by <code>owner</code> at index <code>idx</code>.
 
-====tokenROData====
+Transfers token with id <code>tokenid</code> to address <code>to</code>.
+
+The parameter <code>tokenid</code> SHOULD be a valid NFT. If not, this method SHOULD <code>throw</code> an exception.
+
+The parameter <code>to</code> SHOULD be a 20-byte address. If not, this method SHOULD <code>throw</code> an exception.
+
+The function SHOULD return <code>false</code> if the token that will be transferred has more than one owner.
+
+If the method succeeds, it MUST fire the <code>transfer</code> event, and MUST return <code>true</code>, even if the token is sent to the owner himself.
+
+The function SHOULD check whether the owner address equals the caller contract hash. If so, the transfer SHOULD be processed; If not, the function SHOULD use the SYSCALL <code>Neo.Runtime.CheckWitness</code> to verify the transfer.
+
+If the <code>to</code> address is a deployed contract, the function SHOULD check the <code>payable</code> flag of this contract to decide whether it should transfer the tokens to this contract.
+
+If the transfer is not processed, the function SHOULD return <code>false</code>.
+
 <pre>
-public static byte[] tokenROData(byte[] tokenid)
+public static bool transfer(byte[] from, byte[] to, BigInteger amount, byte[] tokenid)
 </pre>
-Returns the read-only data for token with id <code>tokenid</code>. Read-only data represents immutable data contained in the token, i.e., a property address for a property or the artist's name for a work of art.
 
-====tokenRWData====
+''OPTIONAL'': This method MUST be implemented if <code>decimals() > 0</code>.
+
+Transfers an <code>amount</code> of tokens with id <code>tokenid</code> from address <code>from</code> to address <code>to</code>.
+
+The parameter <code>tokenid</code> SHOULD be a valid NFT. If not, this method SHOULD <code>throw</code> an exception.
+
+The parameters <code>from</code> and <code>to</code> SHOULD be 20-byte addresses. If not, this method SHOULD <code>throw</code> an exception.
+
+The parameter <code>amount</code> SHOULD be greater than or equal to <code>0</code> and SHOULD be less than or equal to <code>pow(10, decimals())</code>. If not, this method SHOULD <code>throw</code> an exception.
+
+The function SHOULD return <code>false</code> if the <code>from</code> account balance does not have enough tokens to spend.
+
+If the method succeeds, it MUST fire the <code>transfer</code> event, and MUST return <code>true</code>, even if the <code>amount</code> is <code>0</code>, or the token is sent to the owner himself.
+
+The function SHOULD check whether the <code>from</code> address equals the caller contract hash. If so, the transfer SHOULD be processed; If not, the function SHOULD use the SYSCALL <code>Neo.Runtime.CheckWitness</code> to verify the transfer.
+
+If the <code>to</code> address is a deployed contract, the function SHOULD check the <code>payable</code> flag of this contract to decide whether it should transfer the tokens to this contract.
+
+If the transfer is not processed, the function SHOULD return <code>false</code>.
+
+====ownerOf====
+
 <pre>
-public static byte[] tokenRWData(byte[] tokenid)
+public static enumerator ownerOf(byte[] tokenid)
 </pre>
-Returns the read-write data for token with id <code>tokenid</code>. Read-write data represents data that can be changed in the token, i.e., the owner of a property or work of art.
+
+Returns an <code>enumerator</code> that contains all the co-owners that own the specified token.
+
+The parameter <code>tokenid</code> SHOULD be a valid NFT. If not, this method SHOULD <code>throw</code> an exception.
 
 ====tokenURI====
+
 <pre>
 public static string tokenURI(byte[] tokenid)
 </pre>
-Returns the URI of token with id <code>tokenid</code>. The URI data of a token supplies a reference to get more information about a specific token or its data.
 
-====transfer====
-<pre>
-public static bool transfer(byte[] from, byte[] to, byte[] tokenid)
-</pre>
-Transfers token with id <code>tokenid</code> from address <code>from</code> to address <code>to</code>. If the <code>from</code> address does not equal the sender of the transaction this returns <code>False</code>, <code>True</code> otherwise.
+Returns a distinct Uniform Resource Identifier (URI) for a given asset. The URI data of a token supplies a reference to get more information about a specific token or its data.
+
+The parameter <code>tokenid</code> SHOULD be a valid NFT. If not, this method SHOULD <code>throw</code> an exception.
+
+====balanceOf====
 
-====transferFrom====
 <pre>
-public static bool transferFrom(byte[] from, byte[] to, byte[] tokenid)
+public static BigInteger balanceOf(byte[] owner, byte[] tokenid)
 </pre>
-Transfers a token with id <code>tokenid</code> from address <code>from</code> to address <code>to</code> if the from address has been approved by the <code>approve()</code> method. If the <code>from</code> address is not the owner of the token or if there is no approval this returns <code>False</code>, <code>True</code> otherwise.
 
-====approve====
+Returns the balance of the specified token for the specified owner's account.
+
+The parameter <code>tokenid</code> SHOULD be a valid NFT. If not, this method SHOULD <code>throw</code> an exception.
+
+The parameter <code>owner</code> SHOULD be a 20-byte address. If not, this method SHOULD <code>throw</code> an exception.
+
+If the <code>owner</code> is an unused address, or it's not the owner of the specified token, this method SHOULD return <code>0</code>.
+
+====tokensOfOwner====
 
 <pre>
-public static bool approve(byte[] owner, byte[] spender, byte[] tokenid, bool revoke)
+public static enumerator tokensOfOwner(byte[] owner)
 </pre>
-Approves token <code>tokenid</code> owned by <code>owner</code> to be spent by <code>spender</code> using the <code>transferFrom()</code> method. If <code>revoke</code> is set to <code>1</code> the approval is revoked. A value of <code>True</code> is returned if the operation is approved. <code>False</code> is returned if the approval is denied because of incorrect permissions (owner is not in fact the owner, for example).
+
+Returns an <code>enumerator</code> that contains all the tokens owned by the specified address.
+
+The parameter <code>owner</code> SHOULD be a 20-byte address. If not, this method SHOULD <code>throw</code> an exception.
 
 ==Rationale==