CODEWITHSUNDEEP
node.jsfirebasefirebase-realtime-databasecallbackdialogflow-es
Rand Abu Salim
Rand Abu Salim

Reputation: 65

Getting response before firebase transaction done

I'm trying to retrieve all the child then when there's match display. I print the value in the console and my code work well there after few second, but when I print it in the agent as a message it show not available before the response because it does not wait. Here is my code:

function retrieveContact(agent) {
  var query = admin.database().ref("/contacts").orderByKey();
  query.once("value")
    .then(function(snapshot) {
        snapshot.forEach(function(childSnapshot) {
            var key = childSnapshot.key;
            var childName = childSnapshot.child('name').val();
            if (agent.parameters.name == childName) {

                console.log('find ' + childName);
                agent.add('The email address for ' + childName + ' is ' + childSnapshot.child('email').val());

            }
            // console.log('testMode'+childName);
        }); //// .then 
    }); //// .once }

SO, how can I wait my response then let the agent show the result? How can I include the promise concept in my code ?

Upvotes: 1

Views: 64

Answers (1)

Prisoner
Prisoner

Reputation: 50701

You don't show your entire Handler function, but if you're doing async operations (such as reading from the firebase db) you must return the Promise. This is how the Handler Dispatcher knows to wait for the Promise to complete before returning a response to the user.

In your case, it is probably as simple as

return query.once("value")
  // etc

Upvotes: 1

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