During activity invocation, it is possible to pass the bot context, as it is declared as a parameter in target functions.

The parameters that can be passed are:

• ProcessedUpdate (and all its subclasses) - current processing update.
• User - if present.
• TelegramBot - current bot instance.

It is also possible to add a custom type for passing.

To do this, add a class that implements Autowiring<T> and mark it with the @Injectable annotation.

After implementing the Autowiring interface - T will be available for passing in target functions and will be obtained through the method described in the interface.

@Injectable
object UserResolver : Autowiring<UserRecord> {
    override suspend fun get(update: ProcessedUpdate, bot: TelegramBot): UserRecord? {
        return userRepository.getUserByTgId(update.user.id)
    }
}

Other parameters declared in functions will be searched in parsed parameters.

Additionally, parsed parameters during passing can be cast to certain types, here is their list:

• String
• Integer
• Long
• Short
• Float
• Double

Moreover, note that if parameters are declared and missing (or in parsed parameters or for example User is missing in Update) or the declared type does not fit the received parameter in the function, null will be passed so be careful.

Summarizing everything, below here is an example of how function parameters are usually formed:

See also

• Update parsing
• Activities & Processors