node.js Https調用返回未定義。 亞馬遜AWS

Question

編輯。 自第一篇文章以來，代碼現已更新：

“現在它的工作方式是這樣的：第一次運行pooltemp是不確定的。如果立即運行一次，我將得到pooltemp = 30（這是新的溫度）。這至少表明對Thingspeak的調用正在工作。如果運行它幾分鍾后再次出現，這是第一次未定義。似乎是AWS在函數完成后將值保留了一段時間。”

我對node.js完全陌生，但是具有以下代碼，這些代碼我大多是使用剪切和粘貼編寫的。 它正在Amazon AWS中運行，以響應Alexa調用。 我正在嘗試讀取Thingspeak通道以獲取池中的溫度。（URL返回一個帶有溫度的json。該通道由esp8266更新，該esp8266正在測量pooltemp並將其發布到該通道。不幸的是，我只得到了未定義的pooltemp我創建了函數getCall（）來獲取Thinspeak的溫度。當我在handlerinput中使用變量pooltemp時，它是未定義的。其他一切工作正常。如果我在handlerinput中對pooltemp進行硬編碼，則得到想要的響應。代碼如下。非常感謝您的幫助。謝謝：

/* eslint-disable  func-names */
/* eslint-disable  no-console */



const Alexa = require('ask-sdk');


var https = require('https');
var pooltemp;


  getCall();




//ThingSpeak Data Access

function getCall() {
  var options = {
    protocol: 'https:', 
    host: 'api.thingspeak.com',
    path: '/channels/494722/feeds.json?api_key=9HILOGJ9P2HRDPNO&results=1',
    method: 'GET'
  };

  var getReq = https.request(options, function(res) {
    console.log("\nstatus code: ", res.statusCode);
    var jsonData = '';
    res.on('data', function(data) {
        jsonData += data;
    });
    res.on('end', function() {
      console.log('We have all the data');
      var result = JSON.parse(jsonData);
      console.log('data: ', result);
      console.log('Pool temperature: ', result.feeds[0].field1);
      // Save the latest pool temperature.
      pooltemp = result.feeds[0].field1;
    });
  });

  //end the request
  getReq.end();
  getReq.on('error', function(err) {
    console.log("Error: ", err);
  });
}


const GetNewFactHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'LaunchRequest' ||
      (request.type === 'IntentRequest' &&
        request.intent.name === 'GetNewFactIntent');
  },



  handle(handlerInput) {


    //  var pooltemp = 22;
    var factIndex;
    const factArr = data;
    if (pooltemp <= 15) {
      factIndex = 0;
    }
    if (15 < pooltemp == pooltemp < 20) {
      factIndex = 1;
    }
    if (20 <= pooltemp == pooltemp < 25) {
      factIndex = 2;
    }
    if (pooltemp >= 25) {
      factIndex = 3;
    }


    const randomFact = factArr[factIndex];
    const speechOutput = 'Hold on a second, I will check for you.<break time="1s"/>Today it is ' + pooltemp + ' degrees in the pool. ' + randomFact;
    return handlerInput.responseBuilder
      .speak(speechOutput)
      .withSimpleCard(SKILL_NAME, randomFact)
      .getResponse();

  },
};

const HelpHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'IntentRequest' &&
      request.intent.name === 'AMAZON.HelpIntent';
  },
  handle(handlerInput) {
    return handlerInput.responseBuilder
      .speak(HELP_MESSAGE)
      .reprompt(HELP_REPROMPT)
      .getResponse();
  },
};

const ExitHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'IntentRequest' &&
      (request.intent.name === 'AMAZON.CancelIntent' ||
        request.intent.name === 'AMAZON.StopIntent');
  },
  handle(handlerInput) {
    return handlerInput.responseBuilder
      .speak(STOP_MESSAGE)
      .getResponse();
  },
};

const SessionEndedRequestHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'SessionEndedRequest';
  },
  handle(handlerInput) {
    console.log(`Session ended with reason: ${handlerInput.requestEnvelope.request.reason}`);

    return handlerInput.responseBuilder.getResponse();
  },
};

const ErrorHandler = {
  canHandle() {
    return true;
  },
  handle(handlerInput, error) {
    console.log(`Error handled: ${error.message}`);

    return handlerInput.responseBuilder
      .speak('Sorry, an error occurred.')
      .reprompt('Sorry, an error occurred.')
      .getResponse();
  },
};

const SKILL_NAME = 'Space Facts';
const GET_FACT_MESSAGE = 'Here\'s today temperature: ';
const HELP_MESSAGE = 'You can say tell me a space fact, or, you can say exit... What can I help you with?';
const HELP_REPROMPT = 'What can I help you with?';
const STOP_MESSAGE = 'Goodbye!';

const data = [
  'It is freezing cold. Swimming only for idiots',
  'It is not for whimps, but you may swim. Do you dare go for it?',
  'Wich is a nice temperature for a norwegian.',
  'This is quite comfortable and a swim should be really nice ',

];

const skillBuilder = Alexa.SkillBuilders.standard();

exports.handler = skillBuilder
  .addRequestHandlers(
    GetNewFactHandler,
    HelpHandler,
    ExitHandler,
    SessionEndedRequestHandler
  )
  .addErrorHandlers(ErrorHandler)
  .lambda();

Answer 1

我已經檢查了一下，並對getCall（）函數進行了一些修改，它現在應該可以工作：

function getCall() {
  var options = {
    protocol: 'https:', 
    host: 'api.thingspeak.com',
    path: '/channels/494722/feeds.json?api_key=9HILOGJ9P2HRDPNO&results=1',
    method: 'GET'
  }

  var getReq = https.request(options, function(res) {
    console.log("\nstatus code: ", res.statusCode);
    var jsonData = '';
    res.on('data', function(data) {
        jsonData += data;
    });
    res.on('end', function() {
       console.log('We have all the data');
       var result = JSON.parse(jsonData);
       console.log('data: ', result);
       console.log('Pool temperature: ', result.feeds[0].field1);
       // Save the latest pool temperature.
       poolTemp = result.feeds[0].field1;
    });
  });

  //end the request
  getReq.end();
  getReq.on('error', function(err) {
    console.log("Error: ", err);
  });
}

getCall();

您也可以在腳本開始時嘗試以下操作：

getCall();
setInterval(getCall, 10000);

這將每10秒刷新池溫度。

Answer 2

當前，您的功能getCall（）正在異步執行，因此pooltemp是未定義的。 由於成功執行getCall（）函數之前的javascript asynchrouns性質，它將繼續到if條件

在這里，我使用javascript回調對getCall函數進行了更改。 同樣，在成功執行getCall函數之后，將在GetNewFactHandler handle（）方法中執行其余條件。

/* eslint-disable  func-names */
/* eslint-disable  no-console */
const Alexa = require('ask-sdk');

var https = require('https');

//ThingSpeak Data Access
function getCall(callback) {
  //initialize options values, the value of the method can be changed to POST to make https post calls
  var options = {
    protocol: 'https:', 
    host: 'api.thingspeak.com',
    path: '/channels/494722/feeds.json?api_key=9HILOGJ9P2HRDPNO&results=1',
    method: 'GET'
  };

  //making the https get call
  https.request(options, function(res) {
    console.log("\nstatus code: ", res.statusCode);
    let data = ''

    // A chunk of data has been recieved from request stream.  
    res.on('data', function(chunk) {
        data += chunk;
    });

    // Once the whole response has been received, return response as callback
    res.on('end', () => {
      console.log('We have all the data');
      var result = JSON.parse(data);
      console.log('data: ', result);
      console.log('Pool temperature: ', result.feeds[0].field1);
      // Save the latest pool temperature.
      const poolTemp = result.feeds[0].field1;
      callback(null, poolTemp);
    });
  })
  .on('error', function(err) {
    callback(err);
  });
}

const GetNewFactHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'LaunchRequest' ||
      (request.type === 'IntentRequest' &&
        request.intent.name === 'GetNewFactIntent');
  },

  handle(handlerInput) {

    getCall((err, pooltemp) => {
        //Error handling implementation
        if(err) {
            console.log("Error: ", err);    
        }
        //Validating condition after successful response from getCall       
        //  var pooltemp = 22;
        var factIndex;
        const factArr = data;
        if (pooltemp <= 15) {
          factIndex = 0;
        }
        if (15 < pooltemp == pooltemp < 20) {
          factIndex = 1;
        }
        if (20 <= pooltemp == pooltemp < 25) {
          factIndex = 2;
        }
        if (pooltemp >= 25) {
          factIndex = 3;
        }

        const randomFact = factArr[factIndex];
        const speechOutput = 'Hold on a second, I will check for you.<break time="1s"/>Today it is ' + pooltemp + ' degrees in the pool. ' + randomFact;
        return handlerInput.responseBuilder
          .speak(speechOutput)
          .withSimpleCard(SKILL_NAME, randomFact)
          .getResponse();
    }
  },
};

const HelpHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'IntentRequest' &&
      request.intent.name === 'AMAZON.HelpIntent';
  },
  handle(handlerInput) {
    return handlerInput.responseBuilder
      .speak(HELP_MESSAGE)
      .reprompt(HELP_REPROMPT)
      .getResponse();
  },
};

const ExitHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'IntentRequest' &&
      (request.intent.name === 'AMAZON.CancelIntent' ||
        request.intent.name === 'AMAZON.StopIntent');
  },
  handle(handlerInput) {
    return handlerInput.responseBuilder
      .speak(STOP_MESSAGE)
      .getResponse();
  },
};

const SessionEndedRequestHandler = {
  canHandle(handlerInput) {
    const request = handlerInput.requestEnvelope.request;
    return request.type === 'SessionEndedRequest';
  },
  handle(handlerInput) {
    console.log(`Session ended with reason: ${handlerInput.requestEnvelope.request.reason}`);

    return handlerInput.responseBuilder.getResponse();
  },
};

const ErrorHandler = {
  canHandle() {
    return true;
  },
  handle(handlerInput, error) {
    console.log(`Error handled: ${error.message}`);

    return handlerInput.responseBuilder
      .speak('Sorry, an error occurred.')
      .reprompt('Sorry, an error occurred.')
      .getResponse();
  },
};

const SKILL_NAME = 'Space Facts';
const GET_FACT_MESSAGE = 'Here\'s today temperature: ';
const HELP_MESSAGE = 'You can say tell me a space fact, or, you can say exit... What can I help you with?';
const HELP_REPROMPT = 'What can I help you with?';
const STOP_MESSAGE = 'Goodbye!';

const data = [
  'It is freezing cold. Swimming only for idiots',
  'It is not for whimps, but you may swim. Do you dare go for it?',
  'Wich is a nice temperature for a norwegian.',
  'This is quite comfortable and a swim should be really nice ',

];

const skillBuilder = Alexa.SkillBuilders.standard();

exports.handler = skillBuilder
  .addRequestHandlers(
    GetNewFactHandler,
    HelpHandler,
    ExitHandler,
    SessionEndedRequestHandler
  )
  .addErrorHandlers(ErrorHandler)
  .lambda();