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This is my code in my js file..and the outcome stores in array result and i can see that by console.log (within js file).... i want to take the result and print in my ejs file.. could you pls guide how to take this ..

my js file contains the sorting function is written as below:

function sortEvents(){
    var MongoClient = require('mongodb').MongoClient;
    var url = "mongodb://localhost:27017/";


    MongoClient.connect(url, function(err, db)
     {
        if (err) throw err;
        var dbo = db.db("mydb");
        var mysort = { entryfees: -1 };
        dbo.collection("eventtrans").find().sort(mysort).toArray(function(err, result) 
        {     
            if (err) throw err;
            console.log(result);
            
            db.close();
            return(result);
            
        })    
     })    
}

module.exports = sortEvents;

my app.js file is as below

the sortEvents is getting called and it works correctly, as i can see the console.log value in my console

sortEvents  = require("./sortevent.js");
app.get("/prlist",function(req,res){
    
    console.log("inside prlist")
    var result=sortEvents(); 
   
    res.render("prlist.ejs",{prlist:result});
});

my ejs prlist.ejs file is as below .. i am trying to print the result values in my ejs screen ..have included the ejs tags as well ..but it is not recognizing prlist ...

  <% prlist.forEach(function(abc){ %>
        <div class="col-md-4 col-sm-6">
            <div >
                <h6><%= abc._id %></h6>
                <h6><%= abc.eventname %></h6>

                <hr>
            </div>
        </div>   
    <% }); %>


when i run the app.js , the error i am getting is like below

TypeError: C:\Suren\NewProject\views\prlist.ejs:22
    20|
    21| <div class="row text-center" style="display:flex; flex-wrap: wrap;">
 >> 22|     <% prlist.forEach(function(abc){ %>
    23|         <div class="col-md-4 col-sm-6">
    24|             <div >
    25|                 <h6><%= abc._id %></h6>

Cannot read property 'forEach' of undefined
    at eval (C:\Suren\NewProject\views\prlist.ejs:11:15)


could you pls help where i am going wrong..

i have changed the code this way ..but not helping..

app.get("/prlist",function(req,res){
    
    console.log("inside prlist")
    //var result= sortEvents();
    sortEvents(function(result) {
        console.log(results);
        // Code that depends on 'result'
        res.render("prlist.ejs",{prlist:result});
    });
});

and my js file looks now as

function sortEvents(result){
    var MongoClient = require('mongodb').MongoClient;
    var url = "mongodb://localhost:27017/";


    MongoClient.connect(url, function(err, db)
     {
        if (err) throw err;
        var dbo = db.db("mydb");
        var mysort = { entryfees: -1 };
        dbo.collection("eventtrans").find().sort(mysort).toArray(function(err, result) 
        {     
            if (err) throw err;
            console.log("inside sortevent");
            console.log(result);
            
            db.close();
            return(result);
            
        })    
     })    
}
Suren
  • 3
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  • Does this answer your question? [How do I return the response from an asynchronous call?](https://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) – Yury Tarabanko Jul 24 '20 at 11:48
  • I tried the way i am calling function as per the instruction but not helps..pls guide how to refactor – Suren Jul 24 '20 at 13:03
  • Update your question accordingly to show your new code. – Yury Tarabanko Jul 24 '20 at 13:41
  • @ Yury -Tarabanko..have changed the code .. pls check..still not helping ..could you pls guide where i am going wrong...thanks – Suren Jul 24 '20 at 15:08

1 Answers1

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Your sortEvents function was not correctly firing the callback you were passing in.

This is because you are:

  • Shadowing the result variable containing your callback by having multiple variables named result
  • Not actually calling the callback function, but rather trying to return it.

Take a look at my slightly modified version of your updated code below. I have:

  • renamed the sortEvents function's result parameter to callback
  • called callback at the end of your asynchronous query result handler.
function sortEvents(callback){
    var MongoClient = require('mongodb').MongoClient;
    var url = "mongodb://localhost:27017/";

    MongoClient.connect(url, function(err, db) {
        if (err) throw err;
        var dbo = db.db("mydb");
        var mysort = { entryfees: -1 };
        dbo.collection("eventtrans").find().sort(mysort).toArray(function(err, result) {     
            if (err) throw err;
            console.log("inside sortevent");
            console.log(result);
            
            db.close();
            callback(result);
        })
     })
}
Russopotomus
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