node.js - 未处理的拒绝: Headers cant be set after they are sent

Question

我正在 Dialogflow 中创建一个聊天机器人。当我尝试将数据添加到数据库时，它抛出了“未处理的拒绝”错误。

这是我的 index.js 文件。

'use strict';

const functions = require('firebase-functions');
const {WebhookClient} = require('dialogflow-fulfillment');
//const {Card, Suggestion} = require('dialogflow-fulfillment');
var admin = require('firebase-admin');
//require("firebase/firestore");
admin.initializeApp(functions.config().firebase);
var firestore = admin.firestore();
//var db = firebase.firestore();
process.env.DEBUG = 'dialogflow:debug'; // enables lib debugging statements

var addRef = firestore.collection('Admission');
exports.dialogflowFirebaseFulfillment = functions.https.onRequest((request, response) => {
  const agent = new WebhookClient({ request, response });
  console.log('Dialogflow Request headers: ' + JSON.stringify(request.headers));
  console.log('Dialogflow Request body: ' + JSON.stringify(request.body));
  console.log("request.body.queryResult.parameters: ", request.body.queryResult.parameters);
  let params = request.body.queryResult.parameters;


  /* function welcome (agent) {
    agent.add(`Welcome to my agent!`);
  } */

  /* function fallback (agent) {
    agent.add(`I didn't understand`);
    agent.add(`I'm sorry, can you try again?`);
  } */

  let responseJson ={};

  function yourFunctionHandler(agent) {
    var docRef = firestore.collection('users');
    name = request.body.queryResult.parameters['myname'];
    coll = request.body.queryResult.parameters['college_name'];
    name = name.charAt(0).toUpperCase() + name.slice(1);
    let balanceresponse = {};
    console.log(name);
    return docRef.add({
      myname: name,
      college: coll
    })
    .then((querySnapshot)=>{
      balanceresponse = {
        "fulfillmentText": 'Sure '+name+', Do you want to know about Admissions, Fees, Graduates and PG, Contact information, Media or Testimonials?'

      }
      console.log('before response.send()');
      response.send(balanceresponse); 
     /*  console.log('before response.send()');
      response.send({
        fulfillmentText:  
             'Sure '+name+', Do you want to know about Admissions, Fees, Graduates and PG, Contact information, Media or Testimonials?'
        //response.json(responseJson);
        }); */
        console.log('after response.send()');
      return 1;
    })
    .catch(error => {
      response.send({
        fulfillmentText:  
          'Something went wrong with the database'
        });
    });
  }

  function AdmissionHandler(agent) {
      console.log("inside Admission Handler");
      let balanceresponse = {};
      let Question = request.body.queryResult.parameters['question'];
      addRef.where("Question", "==", Question)
      .get().then((querySnapshot)=>{
      if (querySnapshot) {
          console.log("Document data:");
          const tips = querySnapshot.docs;
          const tipIndex = Math.floor(Math.random() * tips.length);
          const tip = tips[0];
          balanceresponse = {
            "fulfillmentText": ' Anything else you wanna know?'

         }
         console.log('before response.send()');
         response.send(balanceresponse); 
          /*  response.send({
            fulfillmentText:  
            //firestore.collection(addRef.Answer)+ 
            ' Anything else you wanna know?'
          });  */
          return 1;
      } else {
          // doc.data() will be undefined in this case
          console.log("No such document!");
      }
    return 1;
    })
    .catch(function(error) {
      console.log("Error getting document:", error);
     });


  } 


  // Run the proper function handler based on the matched Dialogflow intent name
  let intentMap = new Map();
 // intentMap.set('Default Welcome Intent', welcome);
 // intentMap.set('Default Fallback Intent', fallback);
  intentMap.set('GetName', yourFunctionHandler);
  intentMap.set('AdmissionCustom', AdmissionHandler);
  agent.handleRequest(intentMap);
});

这是我收到的错误:

我在这里看到了一些类似的问题，但没有一个得到解答。有人可以帮忙吗？我已经被困在这个问题上一个多星期了。

Answer 1

问题是yourFunctionHandler(agent)函数正在异步执行操作，但不返回 Promise。相反，它不会返回任何内容，因此处理会立即返回，而不会发送消息。

因为它看起来像 myDoc.add()返回一个 Promise，这很容易通过 return myDoc.add(...).then(...) 来处理等等。它可能看起来像这样:

  function yourFunctionHandler(agent) {
    return docRef.add({
      myname: name,
      college: coll
    })
    .then(()=>{
      response.send({
        fulfillmentText:  
          'Sure '+name+', Do you want to know about Admissions, Fees, Graduates and PG, Contact information, Media or Testimonials?'
      });
      return 1;
    })
    .catch(error => {
      //console.log('érror',e);
      response.send({
        fulfillmentText:  
          'Something went wrong with the database'
        });
    });
  }

此外，您还自己混合处理响应(通过调用 response.send() )并使用 Dialogflow agent.handleRequest() ，这将为您创建一个响应。

您应该使用 Dialogflow 方法来生成类似于

的回复

agent.add("No such document found.");

或者自己使用 JSON 中的值来确定要调用哪个处理程序，例如

const intentName = request.body.queryResult.intent.name;
const handler = intentMap[intentName];
handler();

(您可能需要改变这一点。从您的代码看来，您正在使用 Dialogflow v1(我已经反射(reflect)过)，并且 v2 的意图名称的路径发生了变化。您还应该检查处理程序是否不存在，可能要发送参数等)