Contract class entrypoints

.gitignore

@@ -1,5 +1,5 @@
-.DS_Store
 .codex
+.DS_Store
 binary_sizes_baseline.json
 baseline.json
 trigger.sh

examples/smart_contracts/always_true.py

@@ -2,5 +2,7 @@
 from opshin.prelude import *
 
 
-def validator(context: ScriptContext) -> None:
-    pass
+@dataclass()
+class AlwaysTrue(Contract):
+    def raw(self, _context: ScriptContext) -> None:
+        pass

examples/smart_contracts/assert_sum.py

@@ -2,9 +2,11 @@
 from opshin.prelude import *
 
 
-def validator(context: ScriptContext) -> None:
-    datum: int = own_datum_unsafe(context)
-    redeemer: int = context.redeemer
-    assert (
-        datum + redeemer == 42
-    ), f"Expected datum and redeemer to sum to 42, but they sum to {datum + redeemer}"
+@dataclass()
+class AssertSum(Contract):
+    def spend_with_datum(
+        self, datum: int, redeemer: int, _context: ScriptContext
+    ) -> None:
+        assert (
+            datum + redeemer == 42
+        ), f"Expected datum and redeemer to sum to 42, but they sum to {datum + redeemer}"

examples/smart_contracts/bitwise.py

@@ -1,22 +1,19 @@
 #!opshin
 from opshin.prelude import *
-from opshin.std.integrity import check_integrity
 from opshin.std.math import *
 
 
-def validator(context: ScriptContext) -> None:
-    """
-    A contract that checks whether the bitwise AND of the datum and redeemer is zero.
-    """
-    maybe_datum = own_datum(context)
-    # it is possible that no datum is attached (new in PlutusV3)
-    if isinstance(maybe_datum, NoOutputDatum):
-        # in that case, no datum was attached and we accept the transaction
+@dataclass()
+class Bitwise(Contract):
+    def spend_no_datum(self, _redeemer: int, _context: ScriptContext) -> None:
         return
-    else:
-        datum: int = maybe_datum.datum
-        # In plutus v3, the redeemer is in the script context
-        redeemer: int = context.redeemer
+
+    def spend_with_datum(
+        self, datum: int, redeemer: int, _context: ScriptContext
+    ) -> None:
+        """
+        A contract that checks whether the bitwise AND of the datum and redeemer is zero.
+        """
         datum_bytes = bytes_big_from_unsigned_int(datum)
         redeemer_bytes = bytes_big_from_unsigned_int(redeemer)
         # compute the bitwise XOR of the two byte arrays

examples/smart_contracts/gift.py

@@ -9,12 +9,15 @@ class WithdrawDatum(PlutusData):
     pubkeyhash: PubKeyHash
 
 
-def validator(context: ScriptContext) -> None:
-    datum: WithdrawDatum = own_datum_unsafe(context)
-    # check that the datum has correct structure (recommended for user inputs)
-    # can be omitted if the datum can not make its way into a permanent script state (i.e., not stored in an output)
-    check_integrity(datum)
-    sig_present = datum.pubkeyhash in context.transaction.signatories
-    assert (
-        sig_present
-    ), f"Required signature missing, expected {datum.pubkeyhash.hex()} but got {[s.hex() for s in context.transaction.signatories]}"
+@dataclass()
+class Gift(Contract):
+    def spend_with_datum(
+        self, datum: WithdrawDatum, _redeemer: Anything, context: ScriptContext
+    ) -> None:
+        # check that the datum has correct structure (recommended for user inputs)
+        # can be omitted if the datum can not make its way into a permanent script state (i.e., not stored in an output)
+        check_integrity(datum)
+        sig_present = datum.pubkeyhash in context.transaction.signatories
+        assert (
+            sig_present
+        ), f"Required signature missing, expected {datum.pubkeyhash.hex()} but got {[s.hex() for s in context.transaction.signatories]}"

examples/smart_contracts/inspect_script_context.py

@@ -2,5 +2,11 @@
 from opshin.prelude import *
 
 
-def validator(context: ScriptContext):
-    print(context.to_cbor())
+# this validator will print the datum, redeemer and script context passed from the node in a readable format
+@dataclass()
+class InspectScriptContext(Contract):
+    def raw(self, context: ScriptContext) -> None:
+        print(f"script context (CBOR hex): {context.to_cbor().hex()}")
+        print(f"script context (native): {context}")
+
+        assert False, "Failing in order to show script logs"

examples/smart_contracts/liquidity_pool.py

@@ -607,37 +607,39 @@ def get_spending_purpose(context: ScriptContext) -> Spending:
     return purpose
 
 
-def validator(context: ScriptContext) -> None:
-    """
-    Validates that the pool is spent correctly
-    DISCLAIMER: This is a simple example to demonstrate onchain based contract upgradeability and should not be used in production.
-    """
-    purpose = get_spending_purpose(context)
-    redeemer: PoolAction = context.redeemer
-    check_integrity(redeemer)
-    datum: PoolState = own_datum_unsafe(context)
-    check_integrity(datum)
-    own_input_info = context.transaction.inputs[redeemer.pool_input_index]
-    assert (
-        own_input_info.out_ref == purpose.tx_out_ref
-    ), "Index of own input does not match purpose"
-
-    own_output = context.transaction.outputs[redeemer.pool_output_index]
-    if isinstance(redeemer, AddLiquidity) or isinstance(redeemer, RemoveLiquidity):
-        check_valid_license_present(
-            redeemer.license_input_index,
-            context.transaction,
-            datum.up_pool_params.license_policy_id,
-        )
-        check_change_liquidity(datum, redeemer, context, own_input_info, own_output)
-    elif isinstance(redeemer, SwapAsset):
-        check_valid_license_present(
-            redeemer.license_input_index,
-            context.transaction,
-            datum.up_pool_params.license_policy_id,
-        )
-        check_swap(datum, redeemer, context, own_input_info, own_output)
-    elif isinstance(redeemer, PoolUpgrade):
-        check_upgrade(datum, redeemer, context, own_input_info, own_output)
-    else:
-        assert False, "Unknown redeemer"
+@dataclass()
+class LiquidityPool(Contract):
+    def spend_with_datum(
+        self, datum: PoolState, redeemer: PoolAction, context: ScriptContext
+    ) -> None:
+        """
+        Validates that the pool is spent correctly
+        DISCLAIMER: This is a simple example to demonstrate onchain based contract upgradeability and should not be used in production.
+        """
+        purpose = get_spending_purpose(context)
+        check_integrity(redeemer)
+        check_integrity(datum)
+        own_input_info = context.transaction.inputs[redeemer.pool_input_index]
+        assert (
+            own_input_info.out_ref == purpose.tx_out_ref
+        ), "Index of own input does not match purpose"
+
+        own_output = context.transaction.outputs[redeemer.pool_output_index]
+        if isinstance(redeemer, AddLiquidity) or isinstance(redeemer, RemoveLiquidity):
+            check_valid_license_present(
+                redeemer.license_input_index,
+                context.transaction,
+                datum.up_pool_params.license_policy_id,
+            )
+            check_change_liquidity(datum, redeemer, context, own_input_info, own_output)
+        elif isinstance(redeemer, SwapAsset):
+            check_valid_license_present(
+                redeemer.license_input_index,
+                context.transaction,
+                datum.up_pool_params.license_policy_id,
+            )
+            check_swap(datum, redeemer, context, own_input_info, own_output)
+        elif isinstance(redeemer, PoolUpgrade):
+            check_upgrade(datum, redeemer, context, own_input_info, own_output)
+        else:
+            assert False, "Unknown redeemer"

examples/smart_contracts/marketplace.py

@@ -53,23 +53,25 @@ def check_owner_signed(signatories: List[PubKeyHash], owner: PubKeyHash) -> None
     ), f"Owner did not sign transaction, requires {owner.hex()} but got {[s.hex() for s in signatories]}"
 
 
-def validator(context: ScriptContext) -> None:
-    purpose = context.purpose
-    datum: Listing = own_datum_unsafe(context)
-    check_integrity(datum)
-    redeemer: ListingAction = context.redeemer
-    check_integrity(redeemer)
-
-    tx_info = context.transaction
-    assert isinstance(purpose, Spending), f"Wrong script purpose: {purpose}"
-    own_utxo = resolve_spent_utxo(tx_info.inputs, purpose)
-    own_addr = own_utxo.address
-
-    check_single_utxo_spent(tx_info.inputs, own_addr)
-    # It is recommended to explicitly check all options with isinstance for user input
-    if isinstance(redeemer, Buy):
-        check_paid(tx_info.outputs, datum.vendor, datum.price)
-    elif isinstance(redeemer, Unlist):
-        check_owner_signed(tx_info.signatories, datum.owner)
-    else:
-        assert False, "Wrong redeemer"
+@dataclass()
+class Marketplace(Contract):
+    def spend_with_datum(
+        self, datum: Listing, redeemer: ListingAction, context: ScriptContext
+    ) -> None:
+        purpose = context.purpose
+        check_integrity(datum)
+        check_integrity(redeemer)
+
+        tx_info = context.transaction
+        assert isinstance(purpose, Spending), f"Wrong script purpose: {purpose}"
+        own_utxo = resolve_spent_utxo(tx_info.inputs, purpose)
+        own_addr = own_utxo.address
+
+        check_single_utxo_spent(tx_info.inputs, own_addr)
+        # It is recommended to explicitly check all options with isinstance for user input
+        if isinstance(redeemer, Buy):
+            check_paid(tx_info.outputs, datum.vendor, datum.price)
+        elif isinstance(redeemer, Unlist):
+            check_owner_signed(tx_info.signatories, datum.owner)
+        else:
+            assert False, "Wrong redeemer"