Additional properites of MessageActionItem

[nemethf]

ShowMessageRequestClientCapabilities of ShowMessageRequest has this:

	messageActionItem?: {
		/**
		 * Whether the client supports additional attributes which
		 * are preserved and sent back to the server in the
		 * request's response.
		 */
		additionalPropertiesSupport?: boolean;
	};

But how should I create a MessageActionItem with additional properties? I tried:

    print(types.MessageActionItem(title="title", asdf="asdf"))
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: MessageActionItem.__init__() got an unexpected keyword argument 'asdf'

Thanks

[alcarney]

It looks like the definition of MessageActionItem in lsprotocol doesn't allow for additional fields...

Does creating your own subclass of MessageActionItem work?

@attrs.define
class AsdfActionItem(types.MessageActionItem):
    asdf: str = attrs.field(default='')

print(AsdfActionItem(title="title", asdf="asdf"))

However, now that I think about it, you would probably also need to use a custom LanguageServerProtocol object so that pygls uses your custom definition when deserialsing the result

from pygls.protocol import LanguageServerProtocol
from pygls.server import LanguageServer

@attrs.define
class AsdfShowMessageResponse:
    id: Optional[Union[int, str]] = attrs.field()
    """The request id."""
    result: Optional[AsdfActionItem] = attrs.field(default=None)
    jsonrpc: str = attrs.field(default="2.0")


class AsdfServerProtocol(LanguageServerProtocol):
    def get_result_type(self, method: str) -> Optional[Type]:
        if method == types.WINDOW_SHOW_MESSAGE_REQUEST:
            return AsdfShowMessageResponse

        super().get_result_type(method)

server = LanguageServer(protocol_cls=AsdfServerProtocol)

It might also be worth opening an issue in the lsprotocol repo and see if it's possible to add support for additional fields to the MessageActionItem class

Hope that helps!

[nemethf]

@alcarney, thank you for the detailed answer. I opened an issue upstream.