<?php
  
  // include config file
  require_once 'config.inc.php';
  
  // prepares a string to be included in an URL
  function _prepare_url_text($string)\; \{$// remove all characters that aren't a-z, 0-9, dash, underscore or space
    NOT_acceptable_characters_regex = '#[^-a-zA-Z0-9_ ]#';
    $string\; =\; preg\_replace($NOT_acceptable_characters_regex, '', $string);$// remove all leading and trailing spaces
    string = trim($string);$// change all dashes, underscores and spaces to dashes
    string = preg_replace('#[-_ ]+#', '-', $string);$// return the modified string
    return string;
  }
  
  // builds a link that contains a category and a product
  function make_category_product_url($category\_name,$category_id, 
                                     $product\_name,$product_id)
  {
    // prepare the product name and category name for inclusion in URL
    $clean\_category\_name\; =\; \_prepare\_url\_text($category_name);
    $clean\_product\_name\; =\; \_prepare\_url\_text($product_name);
  
    // build the keyword-rich URL
    $url\; =\; SITE\_DOMAIN\; .\; \text{'}/Products/\text{'}\; .$clean_category_name . '-C' . $category\_id\; .\; \text{'}/\text{'}\; .$clean_product_name . '-P' . $product\_id\; .\; \text{'}.html\text{'};$// return the URL
    return url;
  }
  
  // builds a link to a media file
  function make_media_url($id,$name, $extension)\; \{$// prepare the medium name for inclusion in URL
    clean_name = _prepare_url_text ($name);$// build the keyword-rich URL 
    url = SITE_DOMAIN . '/' . $clean\_name\; .\; \text{'}-M\text{'}\; .$id . '.' . $extension;$// return the URL
    return url;
  }
  
  ?>