codeigniter教程之多文件上传使用示例(4)

   /**
    * Multile File Upload
    *
    * @access public
    * @param string
    * @return mixed
    */
    public function do_multi_upload($field){
     //Is $_FILES[$field] set? If not, no reason to continue.
     if(!isset($_FILES[$field])){ return false; }

//Is this really a multi upload?
     if(!is_array($_FILES[$field]["name"])){
      //Fallback to do_upload method.
      return $this->do_upload($field);
     }

//Is the upload path valid?
     if(!$this->validate_upload_path()){
      //Errors will already be set by validate_upload_path() so just return FALSE
      return FALSE;
     }

//Every file will have a separate entry in each of the $_FILES associative array elements (name, type, etc).
     //Loop through $_FILES[$field]["name"] as representative of total number of files. Use count as key in
     //corresponding elements of the $_FILES[$field] elements.
     for($i=0; $i<count($_FILES[$field]["name"]); $i++){
      //Was the file able to be uploaded? If not, determine the reason why.
      if(!is_uploaded_file($_FILES[$field]["tmp_name"][$i])){
       //Determine error number.
       $error = (!isset($_FILES[$field]["error"][$i])) ? 4 : $_FILES[$field]["error"][$i];

//Set error.
       switch($error){
        //UPLOAD_ERR_INI_SIZE
        case 1:
         $this->set_error("upload_file_exceeds_limit");
        break;
        //UPLOAD_ERR_FORM_SIZE
        case 2:
         $this->set_error("upload_file_exceeds_form_limit");
        break;
        //UPLOAD_ERR_PARTIAL
        case 3:
         $this->set_error("upload_file_partial");
        break;
        //UPLOAD_ERR_NO_FILE
        case 4:
         $this->set_error("upload_no_file_selected");
        break;
        //UPLOAD_ERR_NO_TMP_DIR
        case 6:
         $this->set_error("upload_no_temp_directory");
        break;
        //UPLOAD_ERR_CANT_WRITE
        case 7:
         $this->set_error("upload_unable_to_write_file");
        break;
        //UPLOAD_ERR_EXTENSION
        case 8:
         $this->set_error("upload_stopped_by_extension");
        break;
        default:
         $this->set_error("upload_no_file_selected");
        break;
       }

//Return failed upload.
       return FALSE;
      }

//Set current file data as class variables.
      $this->file_temp = $_FILES[$field]["tmp_name"][$i];
      $this->file_size = $_FILES[$field]["size"][$i];
      $this->_file_mime_type($_FILES[$field], $i);
      $this->file_type = preg_replace("/^(.+?);.*$/", "\\1", $this->file_type);
      $this->file_type = strtolower(trim(stripslashes($this->file_type), '"'));
      $this->file_name = $this->_prep_filename($_FILES[$field]["name"][$i]);
      $this->file_ext  = $this->get_extension($this->file_name);
      $this->client_name = $this->file_name;