javascript - wit.ai 和 Node.js 入门

Question

我正在尝试使用wit.ai quickstart example 。该示例适用于硬编码值，但当我使用第三方天气 API 并尝试向用户提供响应时，它不起作用。

工作代码:

 const actions = {
         send(request, response) {
           const {sessionId, context, entities} = request;
           const {text, quickreplies} = response;
           console.log('sending...', JSON.stringify(response));
         },
         getForecast({context, entities}) {
           var location = firstEntityValue(entities, 'location');
           if (location) {
             context.forecast = 'sunny in ' + location; // we should call a weather API here
             delete context.missingLocation;
       
           } else {
             context.missingLocation = true;
             delete context.forecast;
           }
           return context;
         },
       };

现在我编写了函数 getWeather({ context,Entity }, location) 来调用第三方天气 API 并获取用户给定位置的天气信息。

非工作代码:

var getWeather = function ({ context, entities }, location) {
  console.log('Entities: ',entities)
  var url = 'http://api.openweathermap.org/data/2.5/weather?q=' + location + '&appid=myAppID';
  request.get(url, function (error, response, body) {
    if (!error && response.statusCode == 200) {
      console.log(typeof body) 
      var weatherObj = JSON.parse(body);
      console.log('weather api res: ', weatherObj.weather[0].description);
      context.forecast = weatherObj.weather[0].description + ' ' + location; // we should call a weather API here
      delete context.missingLocation;
    }
  })
}

const actions = {
  send(request, response) {
    const {sessionId, context, entities} = request;
    const {text, quickreplies} = response;
    console.log('sending...', JSON.stringify(response));
  },
  getForecast({context, entities}) {
    var location = firstEntityValue(entities, 'location');
    if (location) {
      //Call a function which calls the third party weather API and then handles the response message.
      getWeather({ context, entities }, location);
    } else {
      context.missingLocation = true;
      delete context.forecast;
    }
    return context;
  },
};

此外，如果我稍微更改 getWeather() 函数并移动 context.forecast = 'sunny in ' + location;删除 context.missingLocation; 在 request.get() 调用的回调函数之外，它将再次工作，但此时我没有来自第 3 方 api 的天气信息:

工作代码:

var getWeather = function ({ context, entities }, location) {
  //Keeping context.forecast outside the request.get() callback function is useless as we yet to get the weather info from the API
  context.forecast = 'sunny in ' + location;
  delete context.missingLocation;
  console.log('Entities: ',entities)
  var url = 'http://api.openweathermap.org/data/2.5/weather?q=' + location + '&appid=myAppID';
  request.get(url, function (error, response, body) {
    if (!error && response.statusCode == 200) {
      console.log(typeof body) 
      var weatherObj = JSON.parse(body);
      console.log('weather api res: ', weatherObj.weather[0].description);
    }
  })
}

那么如何使 context.forecast = apiRes + location; 线路在 http 调用的回调中工作？我在这里做错了什么？

注意:我从 wit.ai 得到的错误响应:

Error: Oops, I don't know what to do.

at F:\..\node-wit\lib\wit.js:87:15
at process._tickCallback (internal/process/next_tick.js:103:7)

我正在使用 npm 包 request在 Node 内进行 http 调用。

Answer 1

通过正确解决 promise 解决了问题。完整代码如下:

'use strict';

let Wit = null;
let interactive = null;

var getWeather = function ( location) {
  var url = 'http://api.openweathermap.org/data/2.5/weather?q=' + location + '&appid=myAppID';
  return fetch(url, {
    method: 'GET',
    headers: {
      'Content-Type': 'application/json',
      'Accept': 'application/json',
    }
  })
    .then(rsp => {
      var res = rsp.json();
      return res;
    })
    .then(json => {
      if (json.error && json.error.message) {
        throw new Error(json.error.message);
      }
      return json;
    });
}

try {
  // if running from repo
  Wit = require('../').Wit;
  interactive = require('../').interactive;
} catch (e) {
  Wit = require('node-wit').Wit;
  interactive = require('node-wit').interactive;
}

const accessToken = (() => {
  if (process.argv.length !== 3) {
    console.log('usage: node examples/quickstart.js <wit-access-token>');
    process.exit(1);
  }
  return process.argv[2];
})();

// Quickstart example
// See https://wit.ai/ar7hur/quickstart

const firstEntityValue = (entities, entity) => {
  const val = entities && entities[entity] &&
    Array.isArray(entities[entity]) &&
    entities[entity].length > 0 &&
    entities[entity][0].value;
  if (!val) {
    return null;
  }
  return typeof val === 'object' ? val.value : val;
};

const actions = {
  send(request, response) {
    const {sessionId, context, entities} = request;
    const {text, quickreplies} = response;
    return new Promise(function (resolve, reject) {
      console.log('sending...', JSON.stringify(response));
      return resolve();
    });
  },
  getForecast({context, entities}) {
    var location = firstEntityValue(entities, 'location');
    if (location) {
      return new Promise(function (resolve, reject) {
        return getWeather(location).then(weatherJson => {
          context.forecast = weatherJson.weather[0].description + ' in the ' + location;
          delete context.missingLocation;
          return resolve(context);
        })
      });
    } else {
      context.missingLocation = true;
      delete context.forecast;
      return Promise.reject(context);
    }
    return context;
  },
};

const client = new Wit({ accessToken, actions });
interactive(client);