[Помогите] how to add json error

Код:

public function checkusername() {
        $json = array();
        if(isset($this->request->get['username'])) {
            $this->load->model('account/customer');
            $username = $this->request->get['username'];
            $customer_username = $this->model_account_customer->getCustomerByusername($username);           
            
            if (!$customer_username) {
                $json['success'] ='DONE';
            }                                   

        }
        $this->response->setOutput(json_encode($json));
    }

Код:

 <script type="text/javascript">                 
                $('#check-username').bind('click', function() {
                    var username=$('#username').val();
                    if(username!='') {
                        $.ajax({
                            url: 'index.php?route=account/register/checkusername&username='+username,
                            type: 'post',
                            data: $('.form input[type=\'text\']'),
                            dataType: 'json',
                            success: function(json) {
                                $('.success, .warning, .attention, information, .error').remove();
                                if(json['success']) {
                                    $('#notification').html('<div class="success" style="display: none;">username avliable for use <img src="catalog/view/theme/default/image/close.png" alt="" class="close" /></div>');
                                    $('.success').fadeIn('slow');

                                } else {
                                    $('#notification').html('<div class="warning" style="display: none;"> Username aleady in<img src="catalog/view/theme/default/image/close.png" alt="" class="close" /></div>');
                                    $('.warning').fadeIn('slow');
                                }
                            }
                            
                        });
                    } else {
                        $('#notification').html('<div class="warning" style="display: none;">Username must not blank<img src="catalog/view/theme/default/image/close.png" alt="" class="close" /></div>');
                        $('.warning').fadeIn('slow');
                    }
                });
                </script>

if i need to get error when

if(!preg_match("/^[a-zA-Z0-9_\-\s\x{00C0}-\x{017F}]+$/u", $this->request->post['username']))

how to do it?

thank

 

I use this code it worked

PHP:

public function checkusername() {
        $json = array();
        if(isset($this->request->get['username'])) {
            $this->load->model('account/customer');
            $username = $this->request->get['username'];
            $username_exists = $this->model_account_customer->getCustomerByusername($username); 
            $username_unlatin = (!preg_match("/((?:[\x01-\x7F]|[\xC0-\xDF][\x80-\xBF]|[\xE0-\xEF][\x80-\xBF]{2}|[\xF0-\xF7][\x80-\xBF]{3}){1,100})./x", $username));
          
            $disallowed = array();
          
            $disalloweds = explode(',', $this->config->get('config_username_disallowed'));
            foreach ($disalloweds as $disallow) {
                $disallowed[] = trim($disallow);
            }         
            $username_disallow = in_array(strtolower($username), $disallowed);

            if ($username_disallow) {
                $json['username_disallow'] ='DONE';
            } else if ($username_unlatin) {
                $json['username_unlatin'] ='DONE';
            } else if (!$username_exists)  {
                $json['username_exists'] ='DONE';
            }           

        }
        $this->response->setOutput(json_encode($json));
    }

Thank for advice

HTML:

<script type="text/javascript"><!--             
$('#check-username').bind('click', function() {
    var username=$('#username').val();
    if(username!='' && username.length > 4 && username.length < 26 ) {
        $.ajax({
            url: 'index.php?route=sale/customer/checkusername&token=<?php echo $token; ?>&username='+username,
            type: 'post',
            data: $('.form input[type=\'text\']'),
            dataType: 'json',
            success: function(json) {
                $('.alert-username + .error').remove();                               
                if(json['username_disallow']) {
                    $('.alert-username').html('<div class="warning" style="display: none;"><?php echo $error_username_disallow; ?></div>');
                    $('.warning').fadeIn('slow');
                } else if(json['username_unlatin']) {
                    $('.alert-username').html('<div class="warning" style="display: none;"><?php echo $error_username_unlatin; ?></div>');
                    $('.warning').fadeIn('slow');
                } else if(json['username_exists']) {
                    $('.alert-username').html('<div class="success" style="display: none;"><?php echo $text_username_avliable; ?></div>');
                    $('.success').fadeIn('slow');
                } else {
                    $('.alert-username').html('<div class="warning" style="display: none;"><?php echo $error_username_exists; ?></div>');
                    $('.warning').fadeIn('slow');
                }   
            }
                            
        });                       
    } else {
        $('.alert-username + .error').remove();   
        $('.alert-username').html('<div class="warning" style="display: none;"><?php echo $error_username_wordcount; ?></div>');
        $('.warning').fadeIn('slow');
    }
});
//--></script>