class documentation

Subclass me to specify an AMP Command.

Class Method makeArguments Serialize a mapping of arguments using this Command's argument schema.
Class Method makeResponse Serialize a mapping of arguments using this Command's response schema.
Class Method parseArguments Parse a mapping of serialized arguments using this Command's argument schema.
Class Method parseResponse Parse a mapping of serialized arguments using this Command's response schema.
Class Method responder Declare a method to be a responder for a particular command.
Method __init__ Create an instance of this command with specified values for its parameters.
Class Variable arguments A list of 2-tuples of (name, Argument-subclass-instance), specifying the names and values of the parameters which are required for this command.
Class Variable commandName Undocumented
Class Variable commandType The type of Box used to issue commands; useful only for protocol-modifying behavior like startTLS or protocol switching. Defaults to a plain vanilla Box.
Class Variable errors A mapping of subclasses of Exception to wire-protocol tags for errors represented as strs. Responders which raise keys from this dictionary will have the error translated to the corresponding tag on the wire...
Class Variable extra Undocumented
Class Variable fatalErrors like 'errors', but errors in this list will always terminate the connection, despite being of a recognizable error type.
Class Variable response A list like arguments, but instead used for the return value.
Class Variable responseType The type of Box used to respond to this command; only useful for protocol-modifying behavior like startTLS or protocol switching. Defaults to a plain vanilla Box.
Instance Variable requiresAnswer a boolean; defaults to True. Set it to False on your subclass if you want callRemote to return None. Note: this is a hint only to the client side of the protocol. The return-type of a command responder method must always be a dictionary adhering to the contract specified by ...
Instance Variable structured Undocumented
Method _doCommand Encode and send this Command to the given protocol.
@classmethod
def makeArguments(cls, objects, proto): (source)

Serialize a mapping of arguments using this Command's argument schema.

Parameters
objectsa dict with keys similar to the names specified in self.arguments, having values of the types that the Argument objects in self.arguments can parse.
protoan AMP.
Returns
An instance of this Command's commandType.
@classmethod
def makeResponse(cls, objects, proto): (source)

Serialize a mapping of arguments using this Command's response schema.

Parameters
objectsa dict with keys matching the names specified in self.response, having values of the types that the Argument objects in self.response can format.
protoan AMP.
Returns
an AmpBox.
@classmethod
def parseArguments(cls, box, protocol): (source)

Parse a mapping of serialized arguments using this Command's argument schema.

Parameters
boxA mapping of argument names to the seralized forms of those arguments.
protocolThe AMP protocol.
Returns
A mapping of argument names to the parsed forms.
@classmethod
def parseResponse(cls, box, protocol): (source)

Parse a mapping of serialized arguments using this Command's response schema.

Parameters
boxA mapping of response-argument names to the serialized forms of those arguments.
protocolThe AMP protocol.
Returns
A mapping of response-argument names to the parsed forms.
@classmethod
def responder(cls, methodfunc: _T_Callable) -> _T_Callable: (source)

Declare a method to be a responder for a particular command.

This is a decorator.

Use like so:

    class MyCommand(Command):
        arguments = [('a', ...), ('b', ...)]

    class MyProto(AMP):
        def myFunMethod(self, a, b):
            ...
        MyCommand.responder(myFunMethod)

Notes: Although decorator syntax is not used within Twisted, this function returns its argument and is therefore safe to use with decorator syntax.

This is not thread safe. Don't declare AMP subclasses in other threads. Don't declare responders outside the scope of AMP subclasses; the behavior is undefined.

Parameters
methodfunc:_T_CallableA function which will later become a method, which has a keyword signature compatible with this command's arguments list and returns a dictionary with a set of keys compatible with this command's response list.
Returns
_T_Callablethe methodfunc parameter.
def __init__(self, **kw): (source)

Create an instance of this command with specified values for its parameters.

In Python 3, keyword arguments MUST be Unicode/native strings whereas in Python 2 they could be either byte strings or Unicode strings.

A Command's arguments are defined in its schema using bytes names. The values for those arguments are plucked from the keyword arguments using the name returned from _wireNameToPythonIdentifier. In other words, keyword arguments should be named using the Python-side equivalent of the on-wire (bytes) name.

Parameters
**kwa dict containing an appropriate value for each name specified in the arguments attribute of my class.
Raises
InvalidSignatureif you forgot any required arguments.

Undocumented

The type of Box used to issue commands; useful only for protocol-modifying behavior like startTLS or protocol switching. Defaults to a plain vanilla Box.

A mapping of subclasses of Exception to wire-protocol tags for errors represented as strs. Responders which raise keys from this dictionary will have the error translated to the corresponding tag on the wire. Invokers which receive Deferreds from invoking this command with BoxDispatcher.callRemote will potentially receive Failures with keys from this mapping as their value. This mapping is inherited; if you declare a command which handles FooError as 'FOO_ERROR', then subclass it and specify BarError as 'BAR_ERROR', responders to the subclass may raise either FooError or BarError, and invokers must be able to deal with either of those exceptions.

Undocumented

like 'errors', but errors in this list will always terminate the connection, despite being of a recognizable error type.

The type of Box used to respond to this command; only useful for protocol-modifying behavior like startTLS or protocol switching. Defaults to a plain vanilla Box.

requiresAnswer: bool = (source)

a boolean; defaults to True. Set it to False on your subclass if you want callRemote to return None. Note: this is a hint only to the client side of the protocol. The return-type of a command responder method must always be a dictionary adhering to the contract specified by response, because clients are always free to request a response if they want one.

structured = (source)

Undocumented

def _doCommand(self, proto): (source)

Encode and send this Command to the given protocol.

Parameters
protoan AMP, representing the connection to send to.
Returns
a Deferred which will fire or error appropriately when the other side responds to the command (or error if the connection is lost before it is responded to).