from typing import List, Optional, Sequence, Union
from .. import xdr as stellar_xdr
from ..muxed_account import MuxedAccount
from .operation import Operation
__all__ = ["InvokeHostFunction"]
[docs]
class InvokeHostFunction(Operation):
"""The :class:`InvokeHostFunction` object, which represents a InvokeHostFunction
operation on Stellar's network.
Threshold: Medium
See `Interacting with Soroban via Stellar <https://soroban.stellar.org/docs/fundamentals-and-concepts/invoking-contracts-with-transactions>`_.
:param host_function: The host function to invoke.
:param auth: The authorizations required to execute the host function.
:param source: The source account for the operation. Defaults to the transaction's source account.
"""
_XDR_OPERATION_TYPE: stellar_xdr.OperationType = (
stellar_xdr.OperationType.INVOKE_HOST_FUNCTION
)
def __init__(
self,
host_function: stellar_xdr.HostFunction,
auth: Sequence[stellar_xdr.SorobanAuthorizationEntry] = None,
source: Optional[Union[MuxedAccount, str]] = None,
):
super().__init__(source)
self.host_function = host_function
self.auth: List[stellar_xdr.SorobanAuthorizationEntry] = (
list(auth) if auth else []
)
def _to_operation_body(self) -> stellar_xdr.OperationBody:
invoke_host_function_op = stellar_xdr.InvokeHostFunctionOp(
host_function=self.host_function, auth=self.auth
)
body = stellar_xdr.OperationBody(
type=self._XDR_OPERATION_TYPE,
invoke_host_function_op=invoke_host_function_op,
)
return body
[docs]
@classmethod
def from_xdr_object(cls, xdr_object: stellar_xdr.Operation) -> "InvokeHostFunction":
"""Creates a :class:`InvokeHostFunction` object from an XDR Operation object."""
source = Operation.get_source_from_xdr_obj(xdr_object)
assert xdr_object.body.invoke_host_function_op is not None
host_function = xdr_object.body.invoke_host_function_op.host_function
auth = xdr_object.body.invoke_host_function_op.auth
return cls(
host_function=host_function,
auth=auth,
source=source,
)
def __str__(self):
return f"<InvokeHostFunction [host_function={self.host_function}, auth={self.auth}, source={self.source}]>"