jQuery.post not receiving errors from php script

Question

I know this has been asked before and I have looked at every post I could find that deals with this. I still cannot get the jQuery.post function to correctly receive the error from a php script. Here are both.
PHP:

<?php 
##CONFIGURATION
# LIST EMAIL ADDRESS
$toemail = "email here";

# SUBJECT (Subscribe/Remove)
$subject = "Someone has contacted International Designs";

# RESULT PAGE
$location = "../thank-you.php";

## FORM VALUES ##
$myname = $_REQUEST['myname'];
$myemail = $_REQUEST['myemail'];
$mymessage = $_REQUEST['mymessage'];

if ( empty($myname) || empty($myemail) || empty($mymessage) ) {

    exit('{"error":"That value was invalid!"}')

} else {

    # SENDER
    $email = $myname . " <" . $myemail . ">";

    # MAIL BODY
    $body .= "Name: " . $myname . " \n\n";
    $body .= "Email: " . $myemail . " \n\n";
    $body .= "Message: " . $mymessage . " \n\n";
    # add more fields here if required

    ## SEND MESSGAE ##

    mail( $toemail, $subject, $body, "From: $email" ) or die ("Mail could not be sent.");

}

?>

JS:

if (verify(myname, myemail, mymessage, human, hash, patt)) {
  $.post(myform.attr('action'), myform.serialize(), function() {
    $('#email-success').fadeIn();
    myform[0].reset();
    setTimeout("$('#email-success').fadeOut();", 5000);
  }, 'json')
  .fail(function() {
    alert('An error has occurred. Please try again later.')
  });
}

I have tried about 5 different methods already, none of which have worked. When I put 'json' as the datatype in the .post function the .fail always fires, no matter what's in the php script. If I leave datatype out, then .fail never fires under any circumstance. I have a feeling the problem is with the php commands and datatype. Any help is appreciated.

Answer 1

Perhaps it's because you don't change the http header code of your response and don't specify your data type response.

You're php code response to front (jQuery) code with a "200 – OK" status in any case, but you expect an error in some case with an 'HTTP/1.0 400 – Bad Request' response Or a 'HTTP/1.0 500 Internal Server Error'.

And, like say Eggplant, you have to specify your response data type as 'Content-Type: application/json'.

So, the final code would be something like this :

<?php 
...

header('HTTP/1.0 204 – No Content', true, 204);
header('Content-Type: application/json');

if ( empty($myname) || empty($myemail) || empty($mymessage) ) {

    header('HTTP/1.0 400 – Bad Request', true, 400);
    exit('{"error":"That value was invalid!"}')

} else {

    ...

    $send = mail( $toemail, $subject, $body, "From: $email" );
    if (!$send)
        header('HTTP/1.0 500 – Internal Server Error', true, 500);
        exit ('{"error":"Mail could not be sent."}');
    }
}
return;
?>

For the Warning Cannot modify header information - headers already sent by (output started at /homepages/.../design/contact.php:1) you can examine this answer on the same problem.

Output can be:

• Unintentional:
  • Whitespace before
  • UTF-8 Byte Order Mark
  • Previous error messages or notices
• Intentional:
  • print, echo and other functions producing output (like var_dump)
  • Raw areas before

Update after chat session : it's was a UTF-8 BOM problem

Answer 2

Although, yours is a valid JSON data, I always recommend to use json_encode() function to create JSON string.

exit(json_encode(array("error" => "That value was invalid!")));

Another is make sure you send correct headers to ensure the script knows its a json data. So

header('Content-Type: application/json');
exit(json_encode("error" => "That value was invalid!"));

Answer 3

try this

if (verify(myname, myemail, mymessage, human, hash, patt)) {
    $.ajax({
        type    :'POST',
        data    :$("#myformid").serialize(),
        beforeSend:function(){

        },
        success:function(res){
            if(res=='ok'){
                setTimeout("$('#email-success').fadeOut();", 5000);
            }else{
                //read respon from server
                alert(res)
            }
        },
        error:function(){
            //error handler
        }
    });
}

and just example

$send = mail(....);//your mail function here
echo ($send) ? "ok" : "Error";