Simplify transaction signing in examples using 'build_and_sign' method

Author: cffls

docs/requirements.txt

@@ -37,7 +37,7 @@ pygments==2.11.2; python_version >= "3.6" and python_full_version < "3.0.0" or p
 pynacl==1.5.0; python_version >= "3.6"
 pyparsing==3.0.7; python_version >= "3.7"
 pytest-cov==3.0.0; python_version >= "3.6"
-pytest==7.1.0; python_version >= "3.7"
+pytest==7.1.1; python_version >= "3.7"
 pytz==2021.3; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.4.0" and python_version >= "3.6"
 requests==2.27.1; python_version >= "3.7" and python_full_version < "3.0.0" and python_version < "4" or python_version >= "3.7" and python_version < "4" and python_full_version >= "3.6.0"
 retry==0.9.2

docs/source/guides/transaction.rst

@@ -142,35 +142,22 @@ Specify output amount::
 
 Step 6
 
-Create the transaction body using transaction builder::
+Create a signed transaction using transaction builder. Unlike building a raw transaction, where we need to manually
+sign a transaction and build a transaction witness set, transaction builder can build and sign a transaction directly
+with its `build_and_sign` method. The code below tells the builder to build a transaction and sign the transaction
+with a list of signing keys (in this case, we only need the signature from one signing key, `sk`) and send the change
+back to sender's address::
 
-    >>> tx_body = builder.build(change_address=address)
+    >>> tx = builder.build_and_sign([sk], change_address=address)
 
-Transaction ID could be obtained when we are done configuring the transaction body, because is essentially the hash
-of `TransactionBody`::
+Transaction ID could be obtained from the transaction obejct::
 
-    >>> tx_body.id
+    >>> tx.id
     TransactionId(hex='1d40b950ded3a144fb4c100d1cf8b85719da91b06845530e34a0304427692ce4')
 
-Step 7
-
-Sign the transaction body hash and create a complete transaction (same as the step 4 in raw transaction example)::
-
-    >>> # Sign the transaction body hash
-    >>> signature = sk.sign(tx_body.hash())
-    >>> # Alternatively, we can sign the transaction ID as well
-    >>> signature_alternative = sk.sign(tx_body.id.payload)
-    >>> assert signature == signature_alternative
-
-    >>> # Add verification key and the signature to the witness set
-    >>> vk_witnesses = [VerificationKeyWitness(vk, signature)]
-
-    >>> # Create final signed transaction
-    >>> signed_tx = Transaction(tx_body, TransactionWitnessSet(vkey_witnesses=vk_witnesses))
-
 
 By using transaction builder, we no longer need to specify which UTxO to use as transaction input or calculate
-transaction fee, because they are taken care by the transaction builder.
+transaction fee, because they are taken care by the transaction builder. Also, the code becomes much more concise.
 
 A more complex example of using transaction builder could be found
 in this `Github example <https://github.com/cffls/pycardano/blob/main/examples/tx_builder.py>`_.

examples/delegator_loyalty_rewards.py

@@ -91,25 +91,15 @@
 
 builder.auxiliary_data = auxiliary_data
 
-tx_body = builder.build(change_address=Address.from_primitive(CHANGE_ADDRESS))
-
-# Sign the transaction body hash using the payment signing key
-signature = psk.sign(tx_body.hash())
-
-# Add verification key and the signature to the witness set
-vk_witnesses = [VerificationKeyWitness(pvk, signature)]
-
 # Create final signed transaction
-signed_tx = Transaction(
-    tx_body,
-    TransactionWitnessSet(vkey_witnesses=vk_witnesses),
-    auxiliary_data=auxiliary_data,
+signed_tx = builder.build_and_sign(
+    [psk], change_address=Address.from_primitive(CHANGE_ADDRESS)
 )
 
 # Submit signed transaction to the network
 print(signed_tx)
 
 print("#### Transaction id ####")
-print(tx_body.hash().hex())
+print(signed_tx.id)
 context.submit_tx(signed_tx.to_cbor())
 print("Transaction successfully submitted!")

examples/native_token.py

@@ -161,26 +161,8 @@ def load_or_create_key_pair(base_dir, base_name):
 # Build a finalized transaction body with the change returning to our own address
 tx_body = builder.build(change_address=address)
 
-"""Sign transaction and add witnesses"""
-# Sign the transaction body hash using the payment signing key
-payment_signature = payment_skey.sign(tx_body.hash())
-
-# Sign the transaction body hash using the policy signing key because we are minting new tokens
-policy_signature = policy_skey.sign(tx_body.hash())
-
-# Add verification keys and their signatures to the witness set
-vk_witnesses = [
-    VerificationKeyWitness(payment_vkey, payment_signature),
-    VerificationKeyWitness(policy_vkey, policy_signature),
-]
-
 # Create final signed transaction
-signed_tx = Transaction(
-    tx_body,
-    # Beside vk witnesses, We also need to add the policy script to witness set when we are minting new tokens.
-    TransactionWitnessSet(vkey_witnesses=vk_witnesses, native_scripts=native_scripts),
-    auxiliary_data=auxiliary_data,
-)
+signed_tx = builder.build_and_sign([payment_skey, policy_skey], change_address=address)
 
 print("############### Transaction created ###############")
 print(signed_tx)

examples/tx_builder.py

@@ -75,17 +75,8 @@
     )
 )
 
-# Build a finalized transaction body with the change returning to the address we own
-tx_body = builder.build(change_address=address)
-
-# Sign the transaction body hash using the payment signing key
-signature = psk.sign(tx_body.hash())
-
-# Add verification key and the signature to the witness set
-vk_witnesses = [VerificationKeyWitness(pvk, signature)]
-
 # Create final signed transaction
-signed_tx = Transaction(tx_body, TransactionWitnessSet(vkey_witnesses=vk_witnesses))
+signed_tx = builder.build_and_sign([psk], change_address=address)
 
 # Submit signed transaction to the network
 context.submit_tx(signed_tx.to_cbor())