Royalnet Commands

A Royalnet Command is a small script that is run whenever a specific message is sent to a Royalnet interface.

A Command code looks like this:

from royalnet.commands import Command

class PingCommand(Command):
    name = "ping"

    description = "Play ping-pong with the bot."

    def __init__(self, interface):
        # This code is run just once, while the bot is starting
        super().__init__()

    async def run(self, args, data):
        # This code is run every time the command is called
        await data.reply("Pong!")

Creating a new Command

First, think of a name for your command. It’s the name your command will be called with: for example, the “spaghetti” command will be called by typing /spaghetti in chat. Try to keep the name as short as possible, while staying specific enough so no other command will have the same name.

Next, create a new Python file with the name you have thought of. The previously mentioned “spaghetti” command should have a file called spaghetti.py.

Then, in the first row of the file, import the Command class from royalnet, and create a new class inheriting from it:

from royalnet.commands import Command

class SpaghettiCommand(Command):
    ...

Inside the class, override the attributes name and description with respectively the name of the command and a small description of what the command will do:

from royalnet.commands import Command

class SpaghettiCommand(Command):
    name = "spaghetti"

    description = "Send a spaghetti emoji in the chat."

Now override the Command.run() method, adding the code you want the bot to run when the command is called.

To send a message in the chat the command was called in, you can use the CommandData.reply() method:

from royalnet.commands import Command

class SpaghettiCommand(Command):
    name = "spaghetti"

    description = "Send a spaghetti emoji in the chat."

    async def run(self, args, data):
        await data.reply("🍝")

And… it’s done! The command is ready to be added to a bot!

Coroutines and slow operations

You may have noticed that in the previous example I wrote await data.reply("🍝") instead of just data.reply("🍝").

This is because CommandData.reply() isn’t a simple method: it is a coroutine, a special kind of function that

can be executed separately from the rest of the code, allowing the bot to do other things in the meantime.

By adding the await keyword before the data.reply("🍝"), we tell the bot that it can do other things, like

receiving new messages, while the message is being sent.

You should avoid running slow normal functions inside bot commands, as they will stop the bot from working until they

are finished and may cause bugs in other parts of the code!

async def run(self, args, data):
    # Don't do this!
    image = download_1_terabyte_of_spaghetti("right_now", from="italy")
    ...

If the slow function you want does not cause any side effect, you can wrap it with the royalnet.utils.asyncify

function:

async def run(self, args, data):
    # If the called function has no side effect, you can do this!
    image = await asyncify(download_1_terabyte_of_spaghetti, "right_now", from="italy")
    ...

Avoid using time.sleep() function, as it is considered a slow operation: use instead asyncio.sleep(),

a coroutine that does the same exact thing.