If time permits, I will work on the this idea during GSoC (or even after GSoC), after completing my proposed project: Rich Text Editor Integration.

Idea: Attachment Improvements

Brief explanation:

Only basic attachment upload using HTTP uploads (multipart/form-data) is supported right now. Quite a few improvements are possible when JavaScript is available: Limitations of PHP settings upload_max_filesize and max_execution_time can be worked around by sending multiple HTTP requests instead of one. Multiple files can be selected for upload and a queue can be shown with upload status etc.. If images are to be uploaded and the board does not need them in full size, they can be resized prior upload to save bandwidth.

Expected results:

Integration of Plupload or a similar tool that makes attachment upload a nicer experience. Ability to upload multiple files to a forum post, ability to download all attachments of a post, ability to download all attachments of a topic. It has to be ensured that existing security mechanism also apply to uploads made using JavaScript and uploads still work even without JavaScript.

My Patch:

So far, I have succeeded in integrating the Plupload into the phpBB core files (posting_attach_body.html). I have set the allowed file types, the maximum file size,  resized images and enabled ‘select multiple files’ option.

Attachment Improvement - No files attached
Attachment Improvement - 100% attached

Next step in the project is to learn how phpBB upload script works and integrate Plupload with the upload.php. Also attached file comment seems to be an issue.