类和调用非对象上的成员函数

Question

this time i have a hard problem. I have:

[folder] (file)

---

Structure directory

[class]
- (class.page.php)
- (class.main.php)
[core]
- (core.test.php)

Now class.data.php

<?php
  class DataTools {

public function clean($string) {

    if (!empty($string)) {
        $string = addslashes($string);
        $string = mysql_real_escape_string($string);
        $string = (string)$string;
        $string = stripslashes($string);
        $string = str_replace(" ", "", $string);
        $string = str_replace("(", "", $string);
        $string = str_replace("=", "", $string);
        return $string;
    } else {
        echo "Error";
        die();
    }
}  

Now class.page.php

<?php
  class Page {
  public function __construct {
  include "class.data.php";
  $data = New DataTools();
  }
?>

Now core.test.php

<?php
  require_once "../class/class.page.php";
  $page = new Page;
  $nome = $data->clean("exemple"); // line 13
?>

When i open class.test.php it display this: Fatal error: Call to a member function clean() on a non-object in /membri/khchapterzero/core/core.test.php on line 13( this is not important becouse i reduced the page for the topic, but the line in the original page was that i posted, the other line was comments)

Answer 1

This seems ok, if all files are in one folder it works fine, i try and there was no error. check your structures and names. I check on:

Test->
      class.data.php
      class.page.php
      core.test.php

in include only filename. So checka again your paths