def decode_contract_call(contract_abi: list, call_data: str):
call_data_bin = decode_hex(call_data)
method_signature = call_data_bin[:4]
for description in contract_abi:
if description.get('type') != 'function':
continue
method_name = normalize_abi_method_name(description['name'])
arg_types = [item['type'] for item in description['inputs']]
method_id = get_abi_method_id(method_name, arg_types)
if zpad(encode_int(method_id), 4) == method_signature:
args = decode_abi(arg_types, call_data_bin[4:])
return method_name, args
def decode_contract_call(contract_abi, call_data):
call_data = call_data.lower().replace("0x", "")
call_data_bin = decode_hex(call_data)
method_signature = call_data_bin[:4]
for description in contract_abi:
if description.get('type') != 'function':
continue
method_name = normalize_abi_method_name(description['name'])
arg_types = [item['type'] for item in description['inputs']]
method_id = get_abi_method_id(method_name, arg_types)
if zpad(encode_int(method_id), 4) == method_signature:
try:
# TODO: ethereum.abi.decode_abi vs eth_abi.decode_abi
args = decode_abi(arg_types, call_data_bin[4:])
except AssertionError:
# Invalid args
continue
return method_name, args
def decode_contract_call(self, contract_abi: list, TID: str):
Transaction = self.w3.eth.getTransaction(TID)
call_data = str(Transaction.input)
call_data_bin = decode_hex(call_data)
method_signature = call_data_bin[:4]
for description in contract_abi:
if description.get('type') != 'function':
continue
method_name = normalize_abi_method_name(description['name'])
arg_types = [item['type'] for item in description['inputs']]
method_id = get_abi_method_id(method_name, arg_types)
if zpad(encode_int(method_id), 4) == method_signature:
try:
args = decode_abi(arg_types, call_data_bin[4:])
except AssertionError:
# Invalid args
continue
return method_name, args
def _decode_input(contract_abi, call_data):
"""
Decode input data of a transaction according to a contract ABI
Solution from https://ethereum.stackexchange.com/questions/20897/how-to-decode-input-data-from-tx-using-python3?rq=1
Parameters
----------
contract_abi : list
List of contract methods specifications
call_data : str
Input of transaction in a form of 0x(4 bytes of method)(arguments),
i.e. 0x12345678000000000000....
Returns
-------
dict
Name and parsed parameters extracted from the input
None, if there is no such method in ABI, or there was a problem with method arguments
"""
call_data_bin = decode_hex(call_data)
method_signature = call_data_bin[:4]
for description in contract_abi:
if description.get('type') not in ['function', 'event']:
continue
method_name = normalize_abi_method_name(description['name'])
arg_types = [item['type'] for item in description['inputs']]
method_id = get_abi_method_id(method_name, arg_types)
if zpad(encode_int(method_id), 4) == method_signature:
try:
args = decode_abi(arg_types, call_data_bin[4:])
args = [{'type': arg_types[index], 'value': str(value)} for index, value in enumerate(args)]
except AssertionError:
continue
return {
'name': method_name,
'params.type': [arg["type"] for arg in args],
'params.value': [arg["value"] for arg in args]
}