Many spaces before javascript result

Question

I have a login script that should return 'success' or 'failure' respectively, but it adds many spaces before the result, in the console it shows tha value as "<tons of space> success". This is the PHP for the login script:

public function login() {
    global $dbc, $layout;
    if(!isset($_SESSION['uid'])){
        if(isset($_POST['submit'])){
            $username = mysqli_real_escape_string($dbc, trim($_POST['email']));
            $password = mysqli_real_escape_string($dbc, trim($_POST['password']));
            if(!empty($username) && !empty($password)){
                $query = "SELECT uid, email, username, password, hash FROM users WHERE email = '$username' AND password = SHA('$password') AND activated = '1'";
                $data = mysqli_query($dbc, $query);
                if((mysqli_num_rows($data) === 1)){
                    $row = mysqli_fetch_array($data);
                    $_SESSION['uid'] = $row['uid'];
                    $_SESSION['username'] = $row['username'];
                    $_SERVER['REMOTE_ADDR'] = isset($_SERVER["HTTP_CF_CONNECTING_IP"]) ? $_SERVER["HTTP_CF_CONNECTING_IP"] : $_SERVER["REMOTE_ADDR"];
                    $ip = $_SERVER['REMOTE_ADDR'];
                    $user = $row['uid'];
                    $query = "UPDATE users SET ip = '$ip' WHERE uid = '$user' ";
                    mysqli_query($dbc, $query);
                    setcookie("ID", $row['uid'], time()+3600*24);
                    setcookie("IP", $ip, time()+3600*24);
                    setcookie("HASH", $row['hash'], time()+3600*24);
                    echo 'success';
                    exit();
                } else {
                    //$error = '<div class="shadowbar">It seems we have run into a problem... Either your username or password are incorrect or you haven\'t activated your account yet.</div>' ;
                    //return $error;
                $err = 'failure';
                echo($err);
                exit();
                }
            } else {
                //$error = '<div class="shadowbar">You must enter both your username AND password.</div>';
                //return $error;
                $err = "{\"result\":\"failure\"}";
                echo json_encode($err);
                exit();
            }
        }
    } else {
        echo '{"result":"success"}';
        exit();
    }
    return $error;
}

and the form and JS

    <div class="shadowbar"><form id="login" method="post" action="/doLogin">
    <div id="alert"></div>
    <fieldset>

     <legend>Log In</legend>
    <div class="input-group">
      <span class="input-group-addon">E-Mail</span>

      <input type="email" class="form-control" name="email" value="" /><br />
    </div>
    <div class="input-group">
      <span class="input-group-addon">Password</span>

      <input type="password" class="form-control" name="password" />
      </div>

    </fieldset>

    <input type="submit"  class="btn btn-primary" value="Log In" name="submit" />

    </form></div>

$(function login() {
    $("#login").validate({ // initialize the plugin
        // any other options,
        onkeyup: false,
        rules: {
            email: {
                required: true,
                email: true
            },
            password: {
                required: true
            }
        }
    });

    $('form').ajaxForm({
        beforeSend: function() {
            return $("#login").valid();
        },
                success : function(result) {
                    console.log(result);
                    if(result == " success"){
                        window.location = "/index.php";
                    }else if(result == " failure"){
                        $("#alert").html("<div class='alert alert-warning'>Either you're username or password are incorrect, or you've not activated your account.</div>");
                        //$("#alert").show();
                    }
               }
    });
}); 

but the result always has a lot of spaces for some reason. I'm new to JS, so if this is common, I don't already know.

<?php
    error_reporting(E_ALL); ini_set('display_errors', 1);
    define("CCore", true);
    session_start();
    //Load files...
    require_once('include/scripts/settings.php');
    require_once('include/scripts/version.php');
    require('include/scripts/core.class.php');
    require('include/scripts/nbbc_main.php'); 
    $parser = new BBCode;
    $core = new core;
    $admin = new admin;
    require_once('include/scripts/layout.php');
    require_once('include/scripts/page.php');
    //Set Variables...
    global $dbc, $parser, $layout, $main, $settings, $core;
    $page = new pageGeneration;
    $page->Generate();



?>

this is my index, and anything before the page is generated and login() is called, is in there.

Answer 1

I suppose you are using Ajax calls. I had the same problem, but it my case the result hadn't contain spaces, it was returned in new line. The problem was that my script which was requested by Ajax, contained "new line" character before the PHP script. Search your script file for spaces before PHP script starting with <?php //code... If you had included some scripts in the script which returns success note, search them as well.

Answer 2

The comments on the question are most probably correct: the spaces are being (again, probably, nobody can know for sure without reading the whole source) echoed by PHP included before this. For example, if you do:

 <?php
// there's a space before the previous line

you'd get that space in the output.

What you can do is a bit of a hack, you include a header, for example:

header('Content-Type: text/html');

just before your success output, this will (yet again, probably) output something like:

Warning: Cannot modify header information - headers already sent by (output started at /some/file.php:12) in /some/file.php on line 23

(note the "output started" part) and now you know where to start looking.

HTH.

Answer 3

I dont know if it matters but your

if(result == " success"){ // <<<<<< Here is a Problem maybe
                    window.location = "/index.php";
                }else if(result == " failure"){ // <<<<<< Here is a Problem maybe
                    $("#alert").html("<div class='alert alert-warning'>Either you're username or password are incorrect, or you've not activated your account.</div>");
                    //$("#alert").show();
                }

compares your result from the server which is i.e. "success" with " success". There is space too much.

EDIT:: I dont get ether why you jumps between the response format. Sometimes you echo "success" which is plain and good with your if condition but sometimes you return json encodes strings. These Responses you can't just compare with plain text. These Responses you have to Parse into a JSON Object. Then you could compare with:

if (parsedJSONobject.result == "success"){}