tut3_registration.md

Adding registration/states to your bot

Версия на русском языке

Adding states

Telegram doesn't save any user state so that is the thing we should. User state determine the bot reaction. Simple example - we want to add a registration to our bot to collect any data from users. For that purpose lets create enum class of states:

public enum MyUserState {
    UNAUTHORIZED,
    SET_NAME, 
    SET_CITY,
    SET_AGE,
    AUTHORIZED
}

Let's analyze these states:

• UNAUTHORIZED - the state of user that send a message for the first time;
• SET_NAME - bot expects user to input his name;
• SET_CITY - bot expects user to enter his city;
• SET_AGE - bot expects user to input his age;
• AUTHORIZED - the state when bot expects user to enter any command.

What should we do with this enum? Let

Creating states handler

As we did our own class to add commands, we should create class that extends RegistrationBuilder:

public class MyRegistrationBuilder extends RegistrationBuilder<MyUserState> {
    @Override
    public void initialize() {
        
    }
}

Let's add some states...

public class MyRegistrationBuilder extends RegistrationBuilder<MyUserState> {
    @Override
    public void initialize() {
        add(
                MyUserState.UNAUTHORIZED,
                "Who are you?"
        );
    }
}

We added a message that will receive all the users with UNAUTHORIZED state. Let's add more states:

public class MyRegistrationBuilder extends RegistrationBuilder<MyUserState> {
    @Override
    public void initialize() {
        add(
                MyUserState.UNAUTHORIZED,
                "Who are you?"
        );

        add(
                MyUserState.SET_NAME,
                "Nice name, bro",
                "bruh",
                (input, chatId) -> { some logic with return type boolean }
        );

        add(
                MyUserState.SET_CITY,
                "I'm from the same town",
                "bruuuuuuuuuuuh",
                (input, chatId) -> { some logic with return type boolean }
        );

        add(
                MyUserState.SET_AGE,
                "Welcome to the club, buddy!",
                "bruuuuuuuuuuuuuuuuuuuuuuh",
                (input, chatId) -> { some logic with return type boolean }
        );
    }
}

Probably rn you have a lot of questions. It's fine. Coz of two reasons. First -I'm too bad at writing instructions, second - some of your answers will disappear later. One thing that should be said rn - by saying 'logic' I mean the logic, that will change user state, and will return true or false depending on whether you are satisfied with user input or no.

Adding states to our bot

To add states to our bot, we should call the method addRegistration before start method call in Bot Initialization:

public class Main {
    public static void main(String[] args) {
        IBot bot = new BotCreator(
                "token",
                "username"
        )
                .addCommands(new MyCommandsBuilder())
                .addRegistration(new MyRegistrationBuilder(), (chatId) -> { логика определения состояния пользователя }, MyUserState.AUTHORIZED)
                .start();
    }
}

We should add 3 parameters in addRegistration method:

• our class that extends RegistrationBuilder;
• lambda that returns user state by chatId. If user send message to the bot for the first time he actually can't have a state. So as solution I suggest return UNAUTHORIZED state in this expression and set to user SET_NAME state;
• commands handler state. In our case it's AUTHORIZED.

Congratulations, now our bot have registration!

to be continued...