Drupal - How to upload multiple files at once?
clientside_validation (drupal-6 and drupal-7) performs some additional client-side checks, including checks on uploaded file extensions (but not MIME Types). (And, as @tim.plunkett mentioned in the comments, mimedetect is useful for server-side MIME Type validation, but the file must be uploaded to the server in order to be validated.)
For uploading multiple files, consider the following:
- swfupload (drupal-6; Flash)
- plupload (drupal-6 and drupal-7; Flash and several other technologies supported; new/under development)
For uploading multiple images, additionally consider these:
- image_fupload (drupal-6; uses swfupload above)
- jifupload (drupal-5 and drupal-6; free; uses Java applet)
- aurigma (drupal-6; software purchase / service subscription required)
We've had excellent luck with Plupload. It bends over backwards to achieve cross-browser compatibility, using Silverlight, Flash, HTML5, and falling back to classic HTML4 'select file' widgets depending on the browser's capabilities.
The Drupal integration module is a bit rough, but we've used it successfully on a number of large projects to populate Image Fields. In Drupal 7, I believe they've pulled most of the UI and turned it into a pure API module that can be used by tools like Media simply to handle the uploading work. If you want to do anything particularly funky, you'll probably have to write a bit of custom code to handle where the upload widget gets displayed, but it's very solid.
We've managed to tie into its internal events to handle quite a bit of post-processing, and checking for MIMEtypes/kicking back validation errors could probably be done without too much tinkering.
Here's my comparison wiki in the Similar Module Review group. http://groups.drupal.org/node/155764
Dumping the content here as it is now...
Aurigma Mass Uploader for CCK (6.x-2.0) The Aurigma Uploader for Imagefield module integrates the commercial Aurigma Image Uploader with Drupal. Multiple images are uploaded in a single batch into a multiple imagefield.
Image FUpload (6.x-3.0-rc2) Image FUpload (Multiupload) which is an addition to image and CCK's imagefield module, gives the ability to every user who is allowed to upload images by using image module or imagefield module, to upload multiple images with one simple click. All selected images are uploaded via a flash module (swfupload) and are automatically processed.
Plupload integration (6.x-1.x-dev, 7.x-1.0-beta3) Provides integration between for the Plupload widget to upload multiple files and Drupal. Plupload is a GPL licensed multiple file uploading tool that can present widgets in Flash, Gears, HTML 5, Silverlight, BrowserPlus, and HTML4 depending on the capabilities of the client computer.
SWFUpload (6.x-2.0-beta8) The SWFUpload module for Drupal provides a widget for CCK's Filefield and uses the SWFUpload library to allow multiple file uploads simultaneous.
jUpload for Imagefield (6.x-1.x-dev) Have you ever wished you could upload a group of images at once to an imagefield? The jUpload for Imagefield module (jifupload) integrates the JUpload Java applet with the ImageField module for CCK. Multiple images are uploaded in a single batch into an imagefield set for multiple values.
Different approach, same outcome...
ImageField zip support (6.x-1.0-beta2) This is a helper module for ImageField. When uploading multiple images for imagefields with multi-values, this module adds the ability to upload multiple images in zip files instead of individually.
Imagefield Import (5.x-1.5, 6.x-1.10) Imagefield Import allows users with the proper permissions to import a large number of images into a CCK content type which contains a filefield or an imagefield. The module can grab titles and descriptions using EXIF or IPTC. Note: To use this module you must be able to upload images to your server via FTP, SCP, or other methods.