Dialogflow + 外部 API + Google Cloud Functions *無 * Firebase：如何返回履行響應？

Question

我正在嘗試構建一個 Dialogflow 聊天機器人，它通過 Google Cloud Functions 從外部 API 獲取數據，但不使用 Firebase。 盡管進行了大量搜索，但我還沒有找到任何好的示例或模板； 似乎所有可用的示例都使用 Firebase 函數。

我是一個新手程序員，不熟悉 Node.js、Promises 和所有那些花哨的東西，但我發現即使沒有 Firebase（我使用的是付費版本的 Google Cloud）也應該可以通過 Dialogflow 訪問外部 API。

我嘗試使用這個 Dialogflow 天氣 API 示例創建我的 Google Cloud Function，這是我能找到的最接近我需要的東西，即使它也使用 Firebase： https : //github.com/dialogflow/fulfillment-weather-nodejs /blob/master/functions/index.js#L72

問題是我的代碼在“res.on('end'...”行附近的某個地方失敗了，我不知道為什么。谷歌雲 Stackdriver 日志只給出了相當無信息的消息“忽略來自已完成函數的異常"，但沒有告訴我例外是什么。

這是我的 index.js 代碼的編輯版本：

 'use strict'; const rpn = require('request-promise-native'); const http = require('http'); const hostAPI = 'my host API URL goes here'; const url = require('url'); const {WebhookClient} = require('dialogflow-fulfillment'); exports.myGoogleCloudSearch = (req, res) => { const agent = new WebhookClient({request: req, response: res}); // Dialogflow agent // These are logged in Google Cloud Functions console.log('Dialogflow Request headers: ' + JSON.stringify(req.headers)); console.log('Dialogflow Request body: ' + JSON.stringify(req.body)); // Default welcome intent, this comes through to Dialogflow function welcome(agent) { agent.add('This welcome message comes from Google Cloud Functions.'); } // Default fallback intent, this also comes through function fallback(agent) { agent.add('This is the fallback response from Google Cloud Functions.'); } function searchMyInfo(agent) { // get parameters given by user in Dialogflow const param1 = agent.parameters.param1; const param2 = agent.parameters.param2; const param3 = agent.parameters.param3 // this is logged console.log('Parameters fetched from Dialogflow: ' + param1 + ', ' + param2 + ', ' + param3); var myUrl = hostAPI + param1 + param2 + param3; // the URL is correct and also logged console.log('The URL is ' + myUrl); // Everything up to here has happened between Dialogflow and Google Cloud Functions // and inside GCF, and up to here it works // Next, contact the host API to get the requested information via myUrl // Using this as an example but *without* Firebase: // https://github.com/dialogflow/fulfillment-weather-nodejs/blob/master/functions/index.js#L41 function getMyInfo(param1, param2, param3) { console.log('Inside getMyInfo before Promise'); // this is logged return new Promise((resolve, reject) => { console.log('Inside getMyInfo after Promise'); // this is logged console.log('Should get JSON from ' + myUrl); rpn.get(myUrl, (res) => { // The code is run at least up to here, since this is logged: console.log('Inside rpn.get'); // But then the Google Cloud log just says // "Ignoring exception from a finished function" // and nothing below is logged (or run?) let body = ''; // variable to store response chunks res.on('data', (chunk) => {body += chunk;}); // store each response chunk res.on('end', () => { // this is not logged, so something must go wrong here console.log('Inside res.on end block'); // Parse the JSON for desired data var myArray = JSON.parse(body); // fetched JSON parsed into array console.log(myArray); // not logged // Here I have more parsing and filtering of the fetched JSON // to obtain my desired data. This JS works fine for my host API and returns // the correct data if I just run it in a separate html file, // so I've left it out of this example because the problem seems // to be with the Promise(?). // Create the output from the parsed data // to be passed on to the Dialogflow agent let output = agent.add('Parsed data goes here'); console.log(output); resolve(output); // resolve the promise }); // res.on end block end // In case of error res.on('error', (error) => { // this is not logged either console.log('Error calling the host API'); reject(); }); // res.on error end }); // rpn.get end }); // Promise end } // getMyInfo end // call the host API: this does not seem to work since nothing is logged // and no error message is returned getMyInfo(param1, param2, param3).then((output) => { console.log('getMyInfo call started'); // Return the results of the getMyInfo function to Dialogflow res.json({'fulfillmentText': output}); }).catch(() => { // no error message is given either res.json({'fulfillmentText' : 'There was an error in getting the information'}); console.log('getMyInfo call failed'); }); } // searchMyInfo(agent) end // Mapping functions to Dialogflow intents let intentMap = new Map(); intentMap.set('Default Welcome Intent', welcome); // this works intentMap.set('Default Fallback Intent', fallback); // this works intentMap.set('my.search', searchMyInfo); // this does not work agent.handleRequest(intentMap); }; // exports end

所以我的問題是：如何使此代碼工作以將履行響應返回給 Dialogflow？ 默認的歡迎和回退響應確實來自 Google Cloud Functions，但我的自定義意圖 webhook 響應沒有（即使在 Dialogflow 中為 my.search 設置了“啟用 webhook 調用”）。

Answer 1

我確實有同樣的問題，正如你所說，我認為這與 JavaScript 的承諾和異步行為有關。 因為當您調用雲函數時，它會執行然后響應，但該函數不會等待外部 API 調用。

我嘗試了請求客戶端，但是當我看到日志視圖時，雲函數響應后的外部api響應。

所以我選擇使用axios （用於 node.js 的基於 Promise 的 HTTP 客戶端），然后雲功能就可以工作了。

這是 Dialogflow + 外部 API + Google Cloud Functions 的簡單示例：

index.js

'use strict';

const functions = require('firebase-functions');
const { WebhookClient } = require('dialogflow-fulfillment');
const { Card, Suggestion } = require('dialogflow-fulfillment');
var axios = require("axios");

process.env.DEBUG = 'dialogflow:debug'; // enables lib debugging statements

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));

  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?`);
  }

  function helloWorld() {
    return axios({
      method: "GET",
      url: "https://run.mocky.io/v3/197de163-acc3-4c86-a13f-79314fe9da04",
      data: "",
    })
      .then((response) => {
        console.log(response.data.body.greeting); //Hello World
        agent.add(response.data.body.greeting); 
      })
      .catch((error) => {
        console.log(error);
      });
  }

  let intentMap = new Map();
  intentMap.set('Default Welcome Intent', welcome);
  intentMap.set('Default Fallback Intent', fallback);
  intentMap.set('greeting.helloWorld', helloWorld);

  agent.handleRequest(intentMap);
});

請記住還要將axios包添加到package.json ：

{
  "name": "dialogflowFirebaseFulfillment",
  "description": "This is the default fulfillment for a Dialogflow agents using Cloud Functions for Firebase",
  "version": "0.0.1",
  "private": true,
  "license": "Apache Version 2.0",
  "author": "Google Inc.",
  "engines": {
    "node": "10"
  },
  "scripts": {
    "start": "firebase serve --only functions:dialogflowFirebaseFulfillment",
    "deploy": "firebase deploy --only functions:dialogflowFirebaseFulfillment"
  },
  "dependencies": {
    "actions-on-google": "^2.2.0",
    "firebase-admin": "^5.13.1",
    "firebase-functions": "^2.0.2",
    "dialogflow": "^0.6.0",
    "dialogflow-fulfillment": "^0.5.0",
    "axios": "^0.20.0"
  }
}

最后這是我做的一個 post http 查詢，也許你覺得它很有用。

function consulta() {
  // console.log(agent.parameters.consulta);
  // console.log(agent.query);

  var consulta = agent.query.replace(/(\r\n|\n|\r)/gm, " ");

  return axios({
    method: "POST",
    url: "http://jena-fuseki-api:3030/Matricula",
    headers: {
      Accept: "application/sparql-results+json,*/*;q=0.9",
      "Content-Type": "application/x-www-form-urlencoded",
    },
    params: {
      query: consulta,
    },
  })
    .then((response) => {
      var elements = response.data.results.bindings;

      for (var i = 0; i < elements.length; i++) {
        var result = "";
        var obj = elements[i];
        var j = 0;
        var size = Object.size(obj);
        for (var key in obj) {
          var attrName = key;
          var attrValue = obj[key].value;
          result += attrName + ": " + attrValue;
          if (j < size - 1) result += " | ";
          j++;
        }
        console.log(result);
        agent.add(result);
      }
      console.log("----------------------------");
    })
    .catch((error) => {
      console.log("Failed calling jena-fuseki API");
      console.log(error);
    });
}

Dialogflow 中的一些圖片：

Answer 2

可能還有其他問題（我沒有仔細閱讀您的代碼），但其中之一是，盡管您正在執行異步操作，並在對getMyInfo()調用中返回 Promise，但您還需要擁有 Intent Handler searchMyInfo()返回一個 Promise。 這樣處理程序調度程序知道在返回響應之前等待承諾完成。

它看起來也有點......奇怪......你處理響應的方式。 一旦您使用了 dialogflow-fulfillment 庫，您可能應該使用它來生成 JSON（使用agent.add() ），而不是嘗試自己發送 JSON。 我沒有對此進行測試，但可能是因為嘗試自己發送 JSON，然后讓庫嘗試設置 JSON，可能會導致 Dialogflow 拒絕的無效 JSON。

Answer 3

經過大量的反復試驗，我想出了這個 index.js，只要我能夠測試它，它就適用於我的特定用例。 我將它包含在這里以防其他人想使用不同的 API 進行嘗試。 如果您確實測試過，請在此處發表評論！ 我很想知道它如何適用於另一個案例。

 /** * Copyright 2017 Google Inc. All Rights Reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ 'use strict'; // Include nodejs request-promise-native package as dependency // because async API calls require the use of Promises const rpn = require('request-promise-native'); const hostAPI = 'https://my.api.here/'; // root URL of the API const { WebhookClient } = require('dialogflow-fulfillment'); exports.googleCloudSearch = (req, res) => { const agent = new WebhookClient({ request: req, response: res }); // Dialogflow agent console.log('Dialogflow Request headers: ' + JSON.stringify(req.headers)); // testing console.log('Dialogflow Request body: ' + JSON.stringify(req.body)); // testing // Default welcome intent function welcome(agent) { agent.add('Welcome to my chatbot!'); } // Default fallback intent function fallback(agent) { agent.add('Sorry, I don\\'t understand.'); } // Default conversation end function endConversation(agent) { agent.add('Thank you and have a nice day!'); } // Function for passing data to the myapi.search intent in Dialogflow function searchMyApi(agent) { return new Promise((resolve, reject) => { // get parameters given by user in Dialogflow const param1 = agent.parameters.param1; const param2 = agent.parameters.param2; // and so on... console.log(`Parameters from Dialogflow: ${param1}, ${param2}`); // testing // If necessary, format the parameters passed by Dialogflow to fit the API query string. // Then construct the URL used to query the API. var myUrl = `${hostAPI}?parameter_1=${param1}&parameter_2=${param2}`; console.log('The URL is ' + myUrl); // testing // Make the HTTP request with request-promise-native // https://www.npmjs.com/package/request-promise var options = { uri: myUrl, headers: { 'User-Agent': 'Request-Promise-Native' }, json: true }; // All handling of returned JSON data goes under .then and before .catch rpn(options) .then((json) => { var result = ''; // the answer passed to Dialogflow goes here // Make a string out of the returned JSON object var myStringData = JSON.stringify(json); console.log(`This data was returned: ${myStringData}`); // testing // Make an array out of the stringified JSON var myArray = JSON.parse(myStringData); console.log(`This is my array: ${myArray}`); // testing // Code for parsing myArray goes here, for example: if (condition) { // For example, the returned JSON does not contain the data the user wants result = agent.add('Sorry, could not find any results.'); resolve(result); // Promise resolved } else { // If the desired data is found: var output = ''; // put the data here result = agent.add(`Here are the results of your search: ${output}`); resolve(result); // Promise resolved } }) // .then end .catch(() => { // if .then fails console.log('Promise rejected'); let rejectMessage = agent.add('Sorry, an error occurred.'); reject(rejectMessage); // Promise rejected }); // .catch end }); // Promise end } // searchMyApi end // Mapping functions to Dialogflow intents let intentMap = new Map(); intentMap.set('Default Welcome Intent', welcome); intentMap.set('Default Fallback Intent', fallback); intentMap.set('End Conversation', endConversation); intentMap.set('myapi.search', searchMyApi); agent.handleRequest(intentMap); }; // exports end