Allow multiple TokenNames per policy

src/Plutus/Validators/NFT.hs

@@ -9,10 +9,10 @@ import           PlutusTx
 import           PlutusTx.Prelude
 
 {-# INLINEABLE mkPolicy #-}
-mkPolicy :: TxOutRef -> TokenName -> () -> ScriptContext -> Bool
-mkPolicy oref tn () ctx =
+mkPolicy :: TxOutRef -> [TokenName] -> () -> ScriptContext -> Bool
+mkPolicy oref tns () ctx =
   traceIfFalse "Seed UTxO For NFT Not Consumed" hasUTxO
-    && traceIfFalse "Must Mint Exactly One NFT" checkMintedAmount
+    && traceIfFalse "Must Mint Exactly One NFT Per TokenName" checkMintedAmount
   where
     info :: TxInfo
     info = scriptContextTxInfo ctx
@@ -20,17 +20,21 @@ mkPolicy oref tn () ctx =
     hasUTxO :: Bool
     hasUTxO = any ((oref ==) . txInInfoOutRef) $ txInfoInputs info
 
+    ownSymbol :: CurrencySymbol
+    ownSymbol = ownCurrencySymbol ctx
+
+    minted :: Value
+    minted = txInfoMint info
+
     checkMintedAmount :: Bool
-    checkMintedAmount = case flattenValue (txInfoMint info) of
-      [(_, tn', amt)] -> tn' == tn && amt == 1
-      _               -> False
+    checkMintedAmount = and $ map (\x -> valueOf minted ownSymbol x == 1) tns
 
-policy :: TxOutRef -> TokenName -> Scripts.MintingPolicy
+policy :: TxOutRef -> [TokenName] -> Scripts.MintingPolicy
 policy oref tn =
   mkMintingPolicyScript $
     $$(PlutusTx.compile [||\oref' tn' -> Scripts.wrapMintingPolicy $ mkPolicy oref' tn'||])
       `PlutusTx.applyCode` PlutusTx.liftCode oref
       `PlutusTx.applyCode` PlutusTx.liftCode tn
 
-curSymbol :: TxOutRef -> TokenName -> CurrencySymbol
-curSymbol oref tn = scriptCurrencySymbol $ policy oref tn
+curSymbol :: TxOutRef -> [TokenName] -> CurrencySymbol
+curSymbol oref tns = scriptCurrencySymbol $ policy oref tns