class twisted.protocols.amp.Command: (source)
Known subclasses: twisted.protocols.amp.ProtocolSwitchCommand, twisted.protocols.amp.StartTLS, twisted.trial._dist.managercommands.AddError, twisted.trial._dist.managercommands.AddExpectedFailure, twisted.trial._dist.managercommands.AddFailure, twisted.trial._dist.managercommands.AddSkip, twisted.trial._dist.managercommands.AddSuccess, twisted.trial._dist.managercommands.AddUnexpectedSuccess, twisted.trial._dist.managercommands.TestWrite, twisted.trial._dist.workercommands.Run, twisted.trial._dist.workercommands.Start
Subclass me to specify an AMP Command.
| 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 | response | A list like arguments, but instead used for the return value. |
| 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. 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. |
| Class Variable | fatalErrors | like 'errors', but errors in this list will always terminate the connection, despite being of a recognizable error type. |
| 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 | 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 response, because clients are always free to request a response if they want one. |
| Class | __metaclass__ | Metaclass hack to establish reverse-mappings for 'errors' and 'fatalErrors' as class vars. |
| Class Variable | extra | Undocumented |
| Method | __init__ | Create an instance of this command with specified values for its parameters. |
| Instance Variable | structured | Undocumented |
| Class Method | makeResponse | Serialize a mapping of arguments using this Command's response schema. |
| Class Method | makeArguments | Serialize a mapping of arguments using this Command's argument schema. |
| Class Method | parseResponse | Parse a mapping of serialized arguments using this Command's response schema. |
| Class Method | parseArguments | Parse a mapping of serialized arguments using this Command's argument schema. |
| Class Method | responder | Declare a method to be a responder for a particular command. |
| Method | _doCommand | Encode and send this Command to the given protocol. |
List[Tuple[bytes, Argument]])
arguments, but instead used for the return value.List[Tuple[bytes, Argument]])
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.Dict[Type[Exception], bytes])
response, because clients are always free to request a response if they want one.bool)
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 | kw | a dict containing an appropriate value for each name specified in the arguments attribute of my class. |
| Raises | InvalidSignature | if you forgot any required arguments. |
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 | A 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 | the methodfunc parameter. | |
Encode and send this Command to the given protocol.
| Parameters | proto | an 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). | |