Question

in my self-defined module I have this method which will query the db and find if the username exists in my db. I want some values to be returned so in the upper level I will know the query result.

var findUserbyUsername=function(username)
{
    db.users.find({email:username},function(err,result)
    { 

        if(err|!username) {console.log('username not found'); return 0;} 
        else return 1;
    }
    );
}
module.exports.findUser=findUserbyUsername;

in app.js I will call the above method like this

var lt=dbutil.findUser('[e-mail]');

but unfortunately I got undefined….
Can anyone help me workaround this ? Or any other suggestions ?

Answer 1

This is an asynchronous code, of course it’s not going to return anything. You might want the following:

app.js:

dbutil.findUser( '[e-mail]', function( err, data ) {
    if ( err ) throw err;
    // Handle the datas returned "data"
} );

module:

var findUserByUserName = function( username, callback ) {
    db.users.find( { email: username }, function( err, result ) {
       if ( err || !username ) {
           console.log( 'username not found' );

           // Call the function passed as parameter
           callback( err ); // You give "undefined" as second parameter
       }
       else {
           callback( err, result ); // You give the datas back
       }
    } );
} );