CODEWITHSUNDEEP
botschatbotfacebook-chatbot
PirateApp
PirateApp

Reputation: 6230

What is the right way to save/track state inside a Facebook Messenger bot?

If my bot asks different questions and if the user answers each of them, how do I find out which answer relates to which question. There is a field called metadata that you can attach to the sendTextMessage API but when the user responds, this metadata comes in as undefined. Do you guys use any node-cache for tracking state or an FSM such as machina.js? How can I best figure out at what of the conversation we are currently stuck in?

Upvotes: 12

Views: 6070

Answers (5)

user3325400
user3325400

Reputation: 29

I've spent some time working with this. The best solution is to use a database to track the user's conversation flow. The POST object contains the senders ID. You can use this ID to make a row in the database in which you'd definitely need to store this ID, any answers to the questions, and a field to keep track of of which step in the conversation.

Then you can use if statements in your code to return the proper responses. Some example code below:

if( $currentStep == '1' ){

    // Ask Next Question
    $message_to_reply = "Thank you! What's your name?";
    $message_to_reply = '"text":"'.$message_to_reply.'"';

} elseif( $currentStep == '2' ){

    // Ask Next Question
    $message_to_reply = "Thank you! What's your email address?";
    $message_to_reply = '"text":"'.$message_to_reply.'"';


} elseif( $currentStep == '3' ){

    // Ask Next Question
    $message_to_reply = "Thank you! What's your address?";
    $message_to_reply = '"text":"'.$message_to_reply.'"';

}

Upvotes: 1

Danny Sullivan
Danny Sullivan

Reputation: 3844

When your app receives a message, there's no payload or metadata associated with it. This is as opposed to a quick-reply or post-back which can have a payload. The only way to associate a response with a question this is to manually track the conversation state in your app as suggested by @anshuman-dhamoon

To do this, it's best to maintain a state for each user, as well as the next state for each state.

// optionally store this in a database
const users = {}

// an object of state constants
const states = {
    question1: 'question1',
    question2: 'question2',
    closing: 'closing',
}

// mapping of each to state to the message associated with each state
const messages = {
    [states.question1]: 'How are you today?',
    [states.question2]: 'Where are you from?',
    [states.closing]: 'That\'s cool. It\'s nice to meet you!',
}

// mapping of each state to the next state
const nextStates = {
    [states.question1]: states.question2,
    [states.question2]: states.closing,
}

const receivedMessage = (event) => {
    // keep track of each user by their senderId
    const senderId = event.sender.id
    if (!users[senderId].currentState){
        // set the initial state
        users[senderId].currentState = states.question1
    } else {
        // store the answer and update the state
        users[senderId][users[senderId].currentState] = event.message.text
        users[senderId].currentState = nextStates[users[senderId.currentState]]
    }
    // send a message to the user via the Messenger API
    sendTextMessage(senderId, messages[users[senderId].currentState])
}

Note If you wanted, you can even make the values of nextStates into callable functions that take the answer of the current state and branch off into different conversation flows by passing the user to a different state depending on his/her response.

Upvotes: 14

srk_pathan
srk_pathan

Reputation: 396

As per my knowledge,in Facebook chatbot you can send data from user to chatbot just by setting payload from postback buttons as they have given in API reference.

And chatbot won't store your session or any states/flags.you can set status or flags or arrays but all will be lost when you update your application or restart your server.

so,if you really want to set status you should use database for that.and senderID will remain same everytime so you can handle data from database by that particular id for particular user.

For more details checkout technical referance here.

I hope this will help you.if so,kindly mark it as an answer.

Upvotes: 6

steviesh
steviesh

Reputation: 1775

I'm running into this issue myself. Though it hasn't been mentioned at all in their documentation, I don't think attaching an in-memory database is out of the question. It seems that the user_id is the same regardless of when the conversation is initiated.

Making an API call every time the user rejoins the session would probably slow down the performance of the bot. Also, I noticed that you can't really construct a "pseudo-distributed database" by using the metadata key in the API if that is what you were suggesting. The metadata tag can be sent from Server -> Client (Messenger) but not from Client -> Server from what the documentation says.

Upvotes: 1

Anshuman Dhamoon
Anshuman Dhamoon

Reputation: 87

You can have a status code in your code, to keep track of where the user conversation with the bot is.

For eg. if you have 10 questions, keep statuscode = 0 initially, and ask the first question. When you receive a message to your webhook, check if statuscode==0, and store that user message as a response to your first question. Then increment statusCode=1 and ask the next question.

You can have multiple flags and statusCodes to deal with different conversation flows.

Upvotes: 3

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