从promise解析调用返回数据

Passing data back from a promise resolve call

本文关键字:返回 数据 调用 promise      更新时间:2023-09-26

我试图调用一个函数,然后在返回的参数中返回一些数据,我使用promise,但我无法返回返回的数据。

我这里有电话:

  fbUserInfo(recipientId,req).then(function(){
    getSessionData(FB_ID).then(function(rowsJson){
       console.log('%%%%%%%%' + JSON.stringify(rowsJson));
    })
  })

我的功能在这里定义

/*
*  FUNCTION: getSessionData
*  PURPOSE : Get the session data into global variables
*/
function getSessionData(FB_ID){
  var gender, user_name;
  var rowsJson = {'gender': gender, 'user_name': user_name };
  console.log('START to get client data');

  return new Promise((resolve,reject) => {
    client.hmget(FB_ID,'gender',function(err,reply){
        rowsJson.gender = reply;
        console.log('^^^ gender :' + rowsJson.gender);
    });
    client.hmget(FB_ID,'name',function(err,reply){
        rowsJson.user_name = reply;
        console.log('^^^ user_name :' + rowsJson.user_name);
    });

    resolve(rowsJson);
  }); // return

} // getSessionData

/*
*  FUNCTION: fbUserInfo
*  PURPOSE : Called once when displaying the user welcome message
*            to get the Facebook user details an place them in the 
*            session if they dont already exist
*/
function fbUserInfo(id,req) {
  return new Promise((resolve, reject) => {
    var url = 'https://graph.facebook.com/v2.6/' + id; 
    console.log('^^^^ url ' + url);
    const options = {  
     method: 'GET',
    uri: url,
    qs: {
      fields: 'first_name,last_name,profile_pic,locale,timezone,gender',
      access_token: FB_PAGE_TOKEN1
    },
    json: true // JSON stringifies the body automatically
   }
   console.log('^^^ CALL RQ');
   rp(options)    
   .then((response) => {    
       console.log('Suucess' + JSON.stringify(response.gender));
       var profile_pic = JSON.stringify(response.profile_pic).replace(/'"/g, "");
       console.log('1. profile_pic:' + profile_pic);
        // Now find the position of the 6th '/'
       var startPos = nth_occurrence(profile_pic, '/', 6) + 1;
       console.log('1. Start Pos: ' + startPos);  
        // Find the position of the next '.'  
       var stopPos = profile_pic.indexOf(".",startPos) ;
       console.log('2. Stop Pos: ' + stopPos);
       FB_ID   = profile_pic.substring(startPos,stopPos);

       console.log('profile_pic :' + profile_pic);
       console.log('FB_ID :' + FB_ID); 
       var gender = JSON.stringify(response.gender).replace(/'"/g, "");

       var name = JSON.stringify(response.first_name).replace(/'"/g, "");
       console.log('name: ' + name);

        console.log('** Set session variable');

        client.exists("key",FB_ID, function (err, replies) {
        if(!err && replies===1){
          console.log("THE SESSION IS ALREADY PRESENT ");
        }else{
          console.log("THE SESSION DOES NOT EXIST");
          // Now create a session from this
          client.hmset(FB_ID, {
            'gender': gender,
            'name': name
          });
          resolve();
        }});
      })
      .catch((err) => {
       console.log(err)
       reject();
      });

    })
} // fbUserInfo

我得到的是:

1. profile_pic:https://scontent.xx.fbcdn.net/v/t1.0-1/p200x200/xxxxxxxxxx.jpg?oh=f43f7946f07e2bfb16fd0428da6a20e3&oe=5824B5F0
1. Start Pos: 48
2. Stop Pos: 96
profile_pic :https://scontent.xx.fbcdn.net/v/t1.0-1/p200x200/xxxxxxxxx.jpg?oh=f43f7946f07e2bfb16fd0428da6a20e3&oe=5824B5F0
FB_ID :13882352_10154200039865923_27612879517xxxxxxxx
name: Ethan
** Set session variable
^^^ gender :male
^^^ user_name :Ethan
THE SESSION DOES NOT EXIST
START to get client data
%%%%%%%%{}

您没有以正确的方式在promise中使用回调,并且您的promise在您的client.hmget函数完成之前就解决了。你需要承诺链来获得你需要的东西,或者你可以像这样快速修复:

return new Promise((resolve,reject) => {
    client.hmget(FB_ID,'gender',function(err,reply){
        if (err) {
           return reject(err);
        }
        rowsJson.gender = reply;
        console.log('^^^ gender :' + rowsJson.gender);
      client.hmget(FB_ID,'name',function(err,reply){
        if (err) {
           return reject(err);
        }
        rowsJson.user_name = reply;
        console.log('^^^ user_name :' + rowsJson.user_name);
        resolve(rowsJson);
      });
    });
  })