API 调用和回调

Question

我正在尝试创建一个进行 2 个 API 调用的路由，第二个取决于第一个的结果，并且只有在满足某些条件时才需要调用。以下是我遇到的问题。

1. 不管怎样，finalCheck 函数似乎在 forEach 之前被调用？即使包裹在 if 语句中
2. 计数器和 userNamesAvailable 在范围之外不可用 他们被分配进来。

3. 我确信有更好的方法可以做到这一点，并且会喜欢任何相关的 建议。

   router.post('/namecheck', async function(req, res, next) {   
     var name = req.body.name;
     var counter = 0
     var domains = []
     var userNamesAvailable = []
     var dotcom = true
     var answer = ''
   
   getDomains(checkDomains)
   
   // Check domain availabilty
   function getDomains (callback) {
     var url='https://api.ote-godaddy.com/v1/domains/available?checkType=FAST'
     Unirest.post(url)
       .headers({
         "Authorization" : "sso-key ",
         "Content-Type": "application/json"
       })
       .send(
         [
           name + '.com',
           name + '.net',
           name + '.org'
         ]
       )
       .end(function(response) { 
         domains=response.body.domains
         console.log(domains)
         callback(domains)
       })
   
   }
    function checkDomains(domains) {
      var d = 0
   
   //If no data is returned send error
   if(!domains) 
   {
     console.log("No data returned")
     return next("No data returned")
   } else {
     //Check how many domains are unavailable
     for(var i=0; i < domains.length; i++) {
       if(domains[i].available == false){
         d = d + 1
         //Flag if the .com is available
         if(domains[i].domain == name + '.com') {
           dotcom = false
         }
       }
     }
   
     if (d >2) {
       console.log("d is greater than 1")
       answer = 'no'
     //If 2 domains are available and one is .com continue
     } else if (d>1 && dotcom =='false') {
       answer = 'no'
     }
   }
   getUsernames(finalCheck)
   }
   
   function getUsernames(callback){
     // Social Sites to Check
     var sitenames = [ 
       'facebook',
       'twitter',
       'instagram',
       'youtube',
       'slack',
       'blogger'
     ]
   
     // Check Usename availabitliy
     let i = 0
     sitenames.forEach(sitename => {
   
     Unirest.post('https://api.namechk.com/services/check.json')
     .headers({
       'AUTHORIZATION': 'Bearer ',
       'Accept': 'application/vnd.api.v1+json',
     }).send({
       'site': sitename, username: name,
     }).end(function(response) { 
       if(response.body.available == false){
         counter ++
       } else {
         userNamesAvailable.push(response.body)
       }
     });
     i++
   });
   console.log(counter)
   console.log(userNamesAvailable)
   if(i == sitenames.length){
     callback(counter, dotcom)
    }
   }
   
   function finalCheck(counter, dotcom) {
     console.log('Start finalCheck')
     console.log(counter)
     console.log(dotcom)
       //Final Check for is a name is a go or not
       //If one social site is not available and the 
       if(counter == 1 && dotcom =='true') {
         console.log(5-counter + ' social sites available')
         res.send("yes");
       } else {
         res.send("no")
       }
     }
    })
   

Answer 1

按照this question 上的答案。你应该可以使用Promise 来做到这一点。

您只需更改函数getUsernames。

  function getUsernames(callback) {
    // Social Sites to Check
    var sitenames = [
      'facebook',
      'twitter',
      'instagram',
      'youtube',
      'slack',
      'blogger'
    ];

    // Check Usename availabitliy
    let requests = sitenames.map((sitename) => {
      return new Promise((resolve) => {
        Unirest.post('https://api.namechk.com/services/check.json')
          .headers({
            'AUTHORIZATION': 'Bearer ',
            'Accept': 'application/vnd.api.v1+json',
          }).send({
            'site': sitename,
            username: name,
          }).end(function(response) {
            if (response.body.available == false){
              counter++;
            } else {
              userNamesAvailable.push(response.body);
            }
            resolve();
          });
      });  
    });

    Promise.all(requests).then(() => { 
      console.log(userNamesAvailable);
      callback(counter, dotcom);
    });
  }

  function finalCheck() {
    console.log('Start finalCheck')
    console.log(counter)
    console.log(dotcom)
    //Final Check for is a name is a go or not
    //If one social site is not available and the
    if (counter == 1 & dotcom == 'true') {
      console.log(5 - counter + ' social sites available')
      res.send("yes");
    } else {
      res.send("no")
    }
  }

请记住，javascript 中的异步函数是一个特性，而不是你应该与之抗争的东西（我认为你正在尝试将你的 main 函数声明为 async function）。首先尝试了解它们，您会发现它们是一个很大的优势。

那里有很多关于它们的文档... async Fucntion understanding Promises

编辑：不要将您调用的变量global作为参数发送，它们已经在被调用函数中可用。