Developing my life

/**
	 * Moves uploaded file from P4A_UPLOADS_TMP_DIR to P4A_UPLOADS_DIR
	 * @throws P4A_Exception
	 */
	public function saveUpload()
	{
		$field_type = $this->getType();
		if ($field_type=='file') {
			$new_value  = $this->getNewValue();
			$old_value  = $this->getValue();
			$target_dir = P4A_UPLOADS_DIR . '/' . $this->getUploadSubpath();
 
			if (!is_dir($target_dir)) {
				if (!P4A_Mkdir_Recursive($target_dir)) {
					throw new P4A_Exception("Cannot create directory \"$target_dir\"", P4A_FILESYSTEM_ERROR);
				}
			}
 
			$a_new_value = explode(',', substr($new_value, 1, -1 ));
			$a_old_value = explode(',', substr($old_value, 1, -1 ));
 
			if ($old_value === null) {
				if ($new_value !== null) {
					$a_new_value[0] = P4A_Get_Unique_File_Name($a_new_value[0], $target_dir);
					$new_path = $target_dir . '/' . $a_new_value[0];
					$old_path = P4A_UPLOADS_DIR . '/' . $a_new_value[1];
					if (!rename($old_path, $new_path)) {
						throw new P4A_Exception("Cannot rename file \"$old_path\" to \"$new_path\"", P4A_FILESYSTEM_ERROR);
					}
					$a_new_value[1] = P4A_Strip_Double_Slashes(str_replace(P4A_UPLOADS_DIR , '', $new_path));
					$this->setNewValue('{' . join($a_new_value, ',') . '}');
				} else {
					$this->setNewValue(null);
				}
			} else {
				if ($new_value === null) {
					$path = $target_dir . '/' . $a_old_value[0];
					if (!@unlink($path) and @file_exists($path)) {
						throw new P4A_Exception("Cannot delete file \"$path\"", P4A_FILESYSTEM_ERROR);
					}
					$this->setNewValue(null);
				} elseif ($new_value!=$old_value) {
					$path = $target_dir . '/' . $a_old_value[0];
					if (!@unlink($path) and @file_exists($path)) {
						throw new P4A_Exception("Cannot delete file \"$path\"", P4A_FILESYSTEM_ERROR);
					}
					$a_new_value[0] = P4A_Get_Unique_File_Name($a_new_value[0], $target_dir);
					$new_path = $target_dir . '/' . $a_new_value[0];
					$old_path = P4A_UPLOADS_DIR . '/' . $a_new_value[1];
					if (!@rename($old_path, $new_path)) {
						throw new P4A_Exception("Cannot rename file \"$old_path\" to \"$new_path\"", P4A_FILESYSTEM_ERROR);
					}
					$a_new_value[1] = str_replace(P4A_UPLOADS_DIR , '', $new_path);
					$this->setNewValue('{' . join($a_new_value, ',') . '}');
				}
			}
		}		
	}

$this->build("p4a_field","txt_miarchivo")
	->setType("file")
	->setUploadSubpath(directorio_especial) // esto siempre y cuando lo quieras subir dentro de un directorio especial dentro del uploads, sino se subira por defecto en el directorio uploads.
	->setLabel("Archivo: ");

public function guardaData()  {
	// procesos que quieras antes
 
	$this->txt_miarchivo->saveUpload();
 
	// procesos que quieras despues
}