[solved] [modules installation] - Cannot modify header information error

[stratboy]

Hi, I made a quite empty test module. I keep getting this error both on install and uninstall (on admin/positions):

 

Warning: Cannot modify header information - headers already sent by (output started at [...] /prestashop/modules/customshippingrates/customshippingrates.php:93) in [...] /prestashop/classes/Tools.php on line 141

 

The class is really simple now, I emptied almost everything:

 

<?php
/*
* 2013 Luca Reghellin
*/

//controlla l'esistenza della costante (una qualunque).
//Serve solo per prevenire che questo file venga direttamente caricato da hackers
if (!defined('_PS_VERSION_')) exit;

class CustomShippingRates extends Module{
 public function __construct(){
$this->name = 'customshippingrates';
$this->tab = 'shipping_logistics';
$this->version = '1.0';
$this->author = 'Luca Reghellin';
$this->need_instance = 0;
$this->dependencies = array();

parent::__construct();

$this->displayName = $this->l('Custom shipping rates');
$this->description = $this->l('Shipping rates based on items volumes.');

$this->confirmUninstall = $this->l('Are you sure you want to uninstall?');

 //questo è solo un esempio, non è necessario
if (!Configuration::get('CUSTOMSHIPPINGRATES_NAME')) $this->warning = $this->l('No name provided');
 }//END CONSTRUCT
public function install(){
 Configuration::updateValue('CUSTOMSHIPPINGRATES_NAME', 'Custom shipping rates');

return parent::install() &&
   //$this->registerHook('actionCartSave') &&
   $this->registerHook('displayHome');
}
public function uninstall(){
  if (!parent::uninstall() ||
  !Configuration::deleteByName('CUSTOMSHIPPINGRATES_NAME'))
  return false;
  return true;
}
public function hookActionCartSave(){

}

public function hookDisplayHome(){
}//end display top
}//END CLASS

?>

 

 

Could you help me to find out the problem?

Edited May 13, 2013 by stratboy (see edit history)

[Paul C]

Get rid of the ?> at the end of the file.

 

It's unnecessary, really bad practice and the source of all types of problems

[stratboy]

Done. It works. Thank you very much!