WP File naming corrections

<?php

// I like to verify if a function exists just because anyone (including yourself) 
// could screw up the file accidently so always verify, so my functions are wrapped
// inside a if(function_exists('function_name')) condition
    
// Replace wierd non-URL-safe characters
if(!function_exists('dw_replaceChars')) {
    function dw_replaceChars($str) {
		// List all wierd characters and match with what we want
		$unwanted_array = array(
						'Š'=>'S', 'š'=>'s', 'Ž'=>'Z', 'ž'=>'z', 'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A', 'Ä'=>'A', 'Å'=>'A', 
						'Æ'=>'A', 'Ç'=>'C', 'È'=>'E', 'É'=>'E', 'Ê'=>'E', 'Ë'=>'E', 'Ì'=>'I', 'Í'=>'I', 'Î'=>'I', 'Ï'=>'I', 
						'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O', 'Õ'=>'O', 'Ö'=>'O', 'Ø'=>'O', 'Ù'=>'U', 'Ú'=>'U', 'Û'=>'U', 
						'Ü'=>'U', 'Ý'=>'Y', 'Þ'=>'B', 'ß'=>'Ss', 'à'=>'a', 'á'=>'a', 'â'=>'a', 'ã'=>'a', 'ä'=>'a', 'å'=>'a', 
						'æ'=>'a', 'ç'=>'c', 'è'=>'e', 'é'=>'e', 'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i', 'î'=>'i', 'ï'=>'i', 
						'ð'=>'o', 'ñ'=>'n', 'ò'=>'o', 'ó'=>'o', 'ô'=>'o', 'õ'=>'o', 'ö'=>'o', 'ø'=>'o', 'ù'=>'u', 'ú'=>'u', 
						'û'=>'u', 'ý'=>'y', 'þ'=>'b', 'ÿ'=>'y' );
		// Tell PHP to match them all and do the proper replacements
		$str = strtr( $str, $unwanted_array );
		// Return value
		return $str;
	}
}


// URL-safe renaming functionality
if(!function_exists('dw_url')) {
	function dw_url( $str = '' ) {
		// Again, if we've included the previous function, replace the characters
		if(function_exists('dw_replaceChars')) {
			$str = dw_replaceChars( $str );
		}
		// Convert everything to lower case
		$str = strtolower($str);
		// Replace everything not letters (a-z), numbers (0-9), periods or hyphens to nothing
		$str = preg_replace("/[^a-z0-9.-]/", "", $str);
		// Replace any spaces with hyphens
		$str = preg_replace("/[\s-]+/", "-", $str);
		// Return value
		return $str;
	}
}

// Tell WP to deal with the file names
if(!function_exists('dw_safeFileUploads')) {
	// Parameter $file is the uploaded file (managed by WP)
	function dw_safeFileUploads( $file ) {
		// Call the function that corrects the file name
		// No need to call other functions as this does all it needs
		$file['name'] = dw_url( $file['name'] );
		// Return value and use this as the file name
		return $file;
	}
	// WP has a hook that combined functions and calls them when needed
	// Tell WP to use our custom functions
	add_action('wp_handle_upload_prefilter', 'dw_safeFileUploads');
}