Add getApprovedDip721

Author: dansteren

dapps/azle/dip721-nft/index.ts

@@ -227,6 +227,19 @@ export default Canister({
       return Ok(state.nextTxid());
     }
   ),
+  // Not exported as canister method because of incorrect interface.
+  // See https://github.com/Psychedelic/DIP721/issues/5
+  // getApprovedDip721: query([nat64], Result(Principal, Error), (tokenId) => {
+  //   const nft = state.nfts[Number(tokenId)];
+
+  //   if (nft === undefined) {
+  //     return Err({ InvalidTokenId: null });
+  //   }
+
+  //   return nft.approved.Some === undefined
+  //     ? Ok(ic.caller())
+  //     : Ok(nft.approved.Some);
+  // }),
   isApprovedForAllDip721: query([Principal], bool, (operator) => {
     const operators = state.operators.get(ic.caller().toText());
     const callerIsOperator =