rerturning response of an ajax post

Question

i am trying to check if an email exists in the db but the function doesn't return a value.

This is the code:

function checkemail(email)
{
    var returnVal = "";
    if (email.indexOf("@") != -1 && email.indexOf(".") != -1)
    {
        $.post( "registreren.php?email=" + email, function( response ) {
            if(response == 1) { returnVal = 1; }
            if(response == 2) { returnVal = 2; }
        });
    }
    else
    {
        returnVal = 3;
    }//email

    return returnVal;

}

EDIT: email is send as a string

Possible duplicate of [How do I return the response from an asynchronous call?](http://stackoverflow.com/questions/14220321/how-do-i-return-the-response-from-an-asynchronous-call) — James Thorpe, Feb 16 '16 at 10:34

score 0 · Answer 1 · answered Feb 16 '16 at 10:42

0

Can you use something simple like below

$.ajax({
        url: 'registreren.php',
        type: 'post',
        dataType: "json",
        data: {'email': email},
        success: function (response) {
            if (response == 1)
            {
               returnVal = 1; 
            }
            else
            {
               returnVal = 3; 
            }
        }
    });

instead of

$.post( "registreren.php?email=" + email, function( response ) {
            if(response == 1) { returnVal = 1; }
            if(response == 2) { returnVal = 2; }
    });

answered Feb 16 '16 at 10:42

Nitin Sali

339
1
9

All you've done is swap the shorthand for the longhand. It doesn't address the problem at all. – James Thorpe Feb 16 '16 at 10:45
doesn't matter if it resolves the issue..and by the way it has more options you can pass. – Nitin Sali Feb 16 '16 at 11:16
It doesn't resolve the issue though, and if you don't need to pass those options, that's what the shorthand is there for. – James Thorpe Feb 16 '16 at 11:16

score 0 · Accepted Answer · answered Feb 16 '16 at 11:12

I short, You can not return values from ajax calls as it is asynchronous by nature, the statement return value executes before

To address such cases, use callback, a function accepted as argument and which is executed when response is been received (when asynchronous action is completed).

Try this:

function checkemail(email, callback) {
  var returnVal = "";
  if (email.indexOf("@") != -1 && email.indexOf(".") != -1) {
    $.post("registreren.php?email=" + email, function(response) {
      callback(response);
    });
  } else {
    callback(3);
  }
}
checkemail('abc@xyz.com', function(val) {
  alert(val);
});

checkemail('INVALID_EMAIL', function(val) {
  alert(val);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>

rerturning response of an ajax post

2 Answers2