在使用内联编辑器实现的 DialogFlow Messenger 中，setContext() 干扰 setFollowupEvent()

Question

I have an intent for password reset within DialogFlow using a one time password. You tell DF that you want to reset your password, it asks for your LAN ID, it sends an email with a short code to your email of record, you enter the code, and if it's correct, you can reset your password.

After you give your LAN ID, it sets context and triggers a follow up event "verifyCode" which prompts you for the code and then compares it to the stored value. If correct, then it sets context and triggers another follow up event.

It works perfectly in the web integration and the "try it now" box, all the way through, but not in the DialogFlow Messenger integration, where it looks like setting context interferes with the setFollowupEvent function, although it does send the email. I have tested it and if I disable the context setting the follow up event fires, but that's not helpful.

Below is the relevant code and console values.

  function sendOneTimePassword(agent){
    var lanIdParam = request.body.queryResult.outputContexts[0].parameters.lanId;
    var lanId = lanIdParam.toLowerCase();
    var user = userList[lanId]; 
    if (user == null){ 
      agent.add("We could not find a user with that lan ID. Please try again.");
    } else {
    var emailAddress = user.email; 
    var code = generateOneTimePassword(); 
    var deadline = generateExpirationTime();
    sendResetMail(emailAddress, code);
    agent.add("Just a moment, please...");  
      console.log("code = "+code);
    agent.setContext({
            "name": 'projects/BOTNAME/agent/sessions/STRINGOFTEXT/contexts/verify',
            "lifespan": 5,
            "parameters":{"code": code, "deadline": deadline, "lanId": lanId}
    });  
    agent.setFollowupEvent("validateCode");  
    } 
  }

If I remove the setContext method above, the follow up event fires, but then I have no context.

Answer 1

I can see that you are attempting to trigger a verification event [1] but it sometimes fails.

This may be due to how 'setFollowupEvent' works. As you can see here [2], a similar issue where 'setFollowupEvent' caused 'agent.add' to be skipped over, therefore it may not be triggering as you would expect it to.

Instead of setting context, events may instead require event parameters to be set [3].

Sample Node.js code for how to properly use events can be seen here [4].

[1]https://cloud.google.com/dialogflow/docs/events-overview#config

[2] https://github.com/dialogflow/dialogflow-fulfillment-nodejs/issues/102#issuecomment-410088688

[3] https://cloud.google.com/dialogflow/docs/events-custom#webhook

[4] https://github.com/dialogflow/dialogflow-fulfillment-nodejs/blob/master/test/webhook-v2-test.js#L348