edit code

-// api에서 데이터 불러오기
+  // api에서 데이터 불러오기
+  var xml2js = require('xml-js');
+  var urlencode = require('urlencode');
+  var xmlToJson;
+  
+  // 변수들
+  var City; // 도시 이름
+  var Feb_Dust_2018 =0 ;
+  var Mar_Dust_2018 =0 ;
+  var April_Dust_2018 =0 ;
+  var May_Dust_2018 =0 ;
+  var June_Dust_2018 =0 ;
+  var Feb_Dust_2019 =0 ;
+  var Mar_Dust_2019 =0 ;
+  var April_Dust_2019 =0 ;
+  var May_Dust_2019 =0 ;
+  var June_Dust_2019 =0 ;
+  var Feb_Dust_2020 =0 ;
+  var Mar_Dust_2020 =0 ;
+  var April_Dust_2020 =0 ;
+  var May_Dust_2020 =0 ;
+  var June_Dust_2020 =0 ;
+  var check = false;
+  var url;
+  var Dust_Place //측정 도시
+  const request = require('request');
+  const Dust_URL = "http://openAPI.seoul.go.kr:8088/" //미세먼지 api주소_1
+  const Dust_URL2 = "/xml/MonthlyAverageAirQuality/1/5/" //미세먼지 api주소_2
+  const Dust_ServiceKey = "73754a53586a696d38345951716b6b" //api의 key값
 
-var xml2js = require('xml-js');
-var urlencode = require('urlencode');
-var xmlToJson;
-
-//var Dust_Month=0;
-
-var City;
-var Feb_Dust_2018 =0 ;
-var Mar_Dust_2018 =0 ;
-var April_Dust_2018 =0 ;
-var May_Dust_2018 =0 ;
-var June_Dust_2018 =0 ;
-var Feb_Dust_2019 =0 ;
-var Mar_Dust_2019 =0 ;
-var April_Dust_2019 =0 ;
-var May_Dust_2019 =0 ;
-var June_Dust_2019 =0 ;
-var Feb_Dust_2020 =0 ;
-var Mar_Dust_2020 =0 ;
-var April_Dust_2020 =0 ;
-var May_Dust_2020 =0 ;
-var June_Dust_2020 =0 ;
-const request = require('request');
-var url;
-const Dust_URL = "http://openAPI.seoul.go.kr:8088/" //미세먼지 api주소_1
-const Dust_URL2 = "/xml/MonthlyAverageAirQuality/1/5/" //미세먼지 api주소_2
-const Dust_ServiceKey = "73754a53586a696d38345951716b6b" //Dust url의 key값
-const Dust_Place = '/' + urlencode("강남구") //측정한 장소
-
-
-
-//2020년 2월~6월 미세먼지 평균
-function DelayNode_2020(item)
+module.exports = function(app)
 {  
-  return new Promise(function(resolve,reject){
-        setTimeout(function(){
-        //Dust_Place ='/'+ City
-        url = Dust_URL+Dust_ServiceKey+Dust_URL2+item+Dust_Place;
-        //console.log(url)
-        request(url,function(error,res,body) {
-          if(error){
-            console.log('error=>${error}');
-          }
-          else{
-            if(res.statusCode == 200) {
-              var result = body;
-              xmlToJson = xml2js.xml2json(result, {compact: true, spaces: 4});
-              xmlToJson2 = JSON.parse(xmlToJson);
-                if(item == 202002){
-                  Feb_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 202003){
-                  Mar_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 202004){
-                  April_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 202005){
-                  May_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 202006){
-                  June_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+  app.get('/',function(req,res){
+    res.render('City_login')
+  });
+
+  app.get('/city',function(req,res){
+  //2020년 2월~6월 미세먼지 평균
+  function DelayNode_2020(item)
+  {  
+    City = req.query.city;
+    return new Promise(function(resolve,reject){
+          setTimeout(function(){
+          Dust_Place ='/'+ urlencode(req.query.city)
+          url = Dust_URL+Dust_ServiceKey+Dust_URL2+item+Dust_Place;
+          request(url,function(error,res,body) {
+            if(error){
+              console.log('error=>${error}');
+            }
+            else{
+              if(res.statusCode == 200) {
+                var result = body;
+                xmlToJson = xml2js.xml2json(result, {compact: true, spaces: 4});
+                xmlToJson2 = JSON.parse(xmlToJson);
+                  if(item == 202002){
+                    Feb_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 202003){
+                    Mar_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 202004){
+                    April_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 202005){
+                    May_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 202006){
+                    June_Dust_2020 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+              }
             }
           }
-        }
-      });
-      resolve();        
-    },500)
-  })
-}
-async function Dust_Month_2020(Dust_Month_2020){
-  for(let i=0;i<Dust_Month_2020.length;i++)
-  {
-    await DelayNode_2020(Dust_Month_2020[i]);
+        });
+        resolve();        
+      })
+    })
   }
-}
-Dust_Month_2020([202002,202003,202004,202005,202006]);
+  async function Dust_Month_2020(Dust_Month_2020){
+    for(let i=0;i<Dust_Month_2020.length;i++)
+    {
+      await DelayNode_2020(Dust_Month_2020[i]);
+    }
+  }
+  Dust_Month_2020([202002,202003,202004,202005,202006]);
 
-//2019년 2월~6월 미세먼지 평균
-function DelayNode_2019(item)
-{  
-  return new Promise(function(resolve,reject){
-        setTimeout(function(){
-        //Dust_Place ='/'+ City
-        url = Dust_URL+Dust_ServiceKey+Dust_URL2+item+Dust_Place;
-        request(url,function(error,res,body) {
-          if(error){
-            console.log('error=>${error}');
-          }
-          else{
-            if(res.statusCode == 200) {
-              var result = body;
-              xmlToJson = xml2js.xml2json(result, {compact: true, spaces: 4});
-              xmlToJson2 = JSON.parse(xmlToJson);
-                if(item == 201902){
-                  Feb_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201903){
-                  Mar_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201904){
-                  April_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201905){
-                  May_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201906){
-                  June_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+  //2019년 2월~6월 미세먼지 평균
+  function DelayNode_2019(item)
+  {  
+    return new Promise(function(resolve,reject){
+          setTimeout(function(){
+          Dust_Place ='/'+ urlencode(req.query.city)
+          url = Dust_URL+Dust_ServiceKey+Dust_URL2+item+Dust_Place;
+          console.log(url)
+          request(url,function(error,res,body) {
+            if(error){
+              console.log('error=>${error}');
+            }
+            else{
+              if(res.statusCode == 200) {
+                var result = body;
+                xmlToJson = xml2js.xml2json(result, {compact: true, spaces: 4});
+                xmlToJson2 = JSON.parse(xmlToJson);
+                  if(item == 201902){
+                    Feb_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 201903){
+                    Mar_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 201904){
+                    April_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 201905){
+                    May_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                  }
+                  else if(item == 201906){
+                    June_Dust_2019 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+              }
             }
           }
-        }
-      });
-      resolve();        
-    },500)
-  })
-}
-async function Dust_Month_2019(Dust_Month_2019){
-  for(let i=0;i<Dust_Month_2019.length;i++)
-  {
-    await DelayNode_2019(Dust_Month_2019[i]);
+        });
+        resolve();        
+      })
+    })
   }
-}
-Dust_Month_2019([201902,201903,201904,201905,201906]);
+  async function Dust_Month_2019(Dust_Month_2019){
+    for(let i=0;i<Dust_Month_2019.length;i++)
+    {
+      await DelayNode_2019(Dust_Month_2019[i]);
+    }
+  }
+  Dust_Month_2019([201902,201903,201904,201905,201906]);
 
 
-//2018년 2월~6월 미세먼지 평균
-function DelayNode_2018(item)
-{  
-  return new Promise(function(resolve,reject){
-        setTimeout(function(){
-        //Dust_Place ='/'+ City
-        url = Dust_URL+Dust_ServiceKey+Dust_URL2+item+Dust_Place;
-        request(url,function(error,res,body) {
-          if(error){
-            console.log('error=>${error}');
-          }
-          else{
-            if(res.statusCode == 200) {
-              var result = body;
-              xmlToJson = xml2js.xml2json(result, {compact: true, spaces: 4});
-              xmlToJson2 = JSON.parse(xmlToJson);
-                if(item == 201802){
-                  Feb_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201803){
-                  Mar_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201804){
-                  April_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201805){
-                  May_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
-                }
-                else if(item == 201806){
-                  June_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+  //2018년 2월~6월 미세먼지 평균
+  function DelayNode_2018(item)
+  {  
+    return new Promise(function(resolve,reject){
+          setTimeout(function(){
+          Dust_Place ='/'+ urlencode(req.query.city)
+          url = Dust_URL+Dust_ServiceKey+Dust_URL2+item+Dust_Place;
+          request(url,function(error,res,body) {
+            if(error){
+              console.log('error=>${error}');
+            }
+            else{
+              if(res.statusCode == 200) {
+                var result = body;
+                xmlToJson = xml2js.xml2json(result, {compact: true, spaces: 4});
+                xmlToJson2 = JSON.parse(xmlToJson);
+                  if(item == 201802){
+                    Feb_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                    console.log(1)
+                  }
+                  else if(item == 201803){
+                    Mar_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                    console.log(2)
+                  }
+                  else if(item == 201804){
+                    April_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                    console.log(3)
+                  }
+                  else if(item == 201805){
+                    May_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                    console.log(4)
+                  }
+                  else if(item == 201806){
+                    June_Dust_2018 = parseInt(xmlToJson2["MonthlyAverageAirQuality"]["row"]["PM10"]["_text"])
+                    console.log(5)
+                    console.log("Setting Complete!!!")
+                    check = true;
+              }
             }
           }
-        }
-      });
-      resolve();        
-    },500)
-  })
-}
-async function Dust_Month_2018(Dust_Month_2018){
-  for(let i=0;i<Dust_Month_2018.length;i++)
-  {
-    await DelayNode_2018(Dust_Month_2018[i]);
+        });
+        resolve();        
+      })
+    })
   }
-}
-Dust_Month_2018([201802,201803,201804,201805,201806]);
+  async function Dust_Month_2018(Dust_Month_2018){
+    for(let i=0;i<Dust_Month_2018.length;i++)
+    {
+      await DelayNode_2018(Dust_Month_2018[i]);
+    } 
+  }
+  Dust_Month_2018([201802,201803,201804,201805,201806]);
 
-module.exports = function(app)
-{  
-  app.get('/',function(req,res){
-    res.render('City_login')
-    City = req.query.city;
-    console.log(City)
-  });
-  app.get('/city',function(req,res){
+  //값을 다 받고난뒤 index.ejs에 값 보내주기
+  if(check == true){
     res.render('index',{
         Feb_Dust_2018,
         Mar_Dust_2018,
@@ -194,7 +200,9 @@ module.exports = function(app)
         Mar_Dust_2020,
         April_Dust_2020,
         May_Dust_2020,
-        June_Dust_2020
+        June_Dust_2020,
+        City
       })
-   });
-}
\ No newline at end of file
+    }
+  });
+}