tx.new_swap: add initializer, `swap_proto_mod` attribute

mmgen/proto/btc/tx/new_swap.py

@@ -41,10 +41,6 @@ class NewSwap(New, TxNewSwap):
 
 	async def process_swap_cmdline_args(self, cmd_args, addrfiles):
 
-		from ....protocol import init_proto
-		import importlib
-		sp = importlib.import_module(f'mmgen.swap.proto.{self.swap_proto}')
-
 		class CmdlineArgs: # listed in command-line order
 			# send_coin      # required: uppercase coin symbol
 			send_amt  = None # optional: Omit to skip change addr and send value of all inputs minus fees to vault
@@ -102,6 +98,8 @@ class NewSwap(New, TxNewSwap):
 			if args_in: # done parsing, all args consumed
 				self.cfg._usage()
 
+		from ....protocol import init_proto
+		sp = self.swap_proto_mod
 		args_in = list(cmd_args)
 		args = CmdlineArgs()
 		parse()

mmgen/tx/bump.py

@@ -42,6 +42,9 @@ class Bump(Completed, NewSwap):
 					setattr(self, attr, getattr(Base, attr))
 			self.outputs = self.OutputList(self)
 			self.cfg = kwargs['cfg'] # must use current cfg opts, not those from orig_tx
+		elif self.is_swap:
+			import importlib
+			self.swap_proto_mod = importlib.import_module(f'mmgen.swap.proto.{self.swap_proto}')
 
 		if not self.is_replaceable():
 			die(1, f'Transaction {self.txid} is not replaceable')

mmgen/tx/new.py

@@ -82,12 +82,6 @@ class New(Base):
 	chg_autoselected = False
 	_funds_available = namedtuple('funds_available', ['is_positive', 'amt'])
 
-	def __init__(self, *args, target=None, **kwargs):
-		if target == 'swaptx':
-			self.is_swap = True
-			self.swap_proto = kwargs['cfg'].swap_proto
-		super().__init__(*args, **kwargs)
-
 	def warn_insufficient_funds(self, amt, coin):
 		msg(self.msg_insufficient_funds.format(amt.hl(), coin))
 

mmgen/tx/new_swap.py

@@ -17,9 +17,15 @@ from .new import New
 class NewSwap(New):
 	desc = 'swap transaction'
 
-	def update_vault_output(self, amt):
+	def __init__(self, *args, **kwargs):
 		import importlib
-		sp = importlib.import_module(f'mmgen.swap.proto.{self.swap_proto}')
+		self.is_swap = True
+		self.swap_proto = kwargs['cfg'].swap_proto
+		self.swap_proto_mod = importlib.import_module(f'mmgen.swap.proto.{self.swap_proto}')
+		New.__init__(self, *args, **kwargs)
+
+	def update_vault_output(self, amt):
+		sp = self.swap_proto_mod
 		c = sp.rpc_client(self, amt)
 
 		from ..util import msg