Upload Attachments to QCLF Topics and Messages
QCLF attachments are available only to signed-in users when the Category Attachments feature is enabled, the user has attachment.upload, and no effective interaction sanction blocks the action.
Each submission accepts up to five allowed files, with a 10 MB limit per file.
Where Attachments Can Be Added
- When creating a permanent Traditional Discussion Topic.
- When posting a permanent Message.
- When editing an existing Topic or Message, if upload permission still applies.
- Live-session chat Messages do not accept attachments.
- Guest Topics/Messages do not accept attachments.
Current File Limits
| Limit | Current 1.1.27 behavior |
|---|---|
| Files per submission | Up to 5 saved files. |
| Size | Maximum 10 MB per file. |
| Images | jpg, jpeg, png, gif, webp |
| Documents/data | pdf, txt, csv, zip, doc, docx, xls, xlsx, ppt, pptx |
Server Validation
QCLF normalizes Joomla’s uploaded-file structure, checks the PHP upload result, rejects zero-byte/oversize files, requires an allowed extension, verifies the temporary upload with is_uploaded_file(), and reads the file before saving.
For image treatment, the extension must be an image extension and detected MIME must start with image/. Image dimensions are recorded when available.
Duplicate-Abuse Window
QCLF hashes each file with SHA-256. By default, the same signed-in user cannot rapidly re-upload the identical bytes inside the configured duplicate-attachment window, which defaults to 60 seconds and can be adjusted/disabled by the administrator.
What Gets Stored
The attachment row records owner, parent type/ID, original/stored names, MIME, extension, byte size, dimensions, SHA-256, image flag, timestamps, and the file bytes themselves. QCLF stores the bytes in the database rather than publishing an executable upload path.
Community Discussion
Want to compare forum workflows, share practical QCLF tips, or discuss how other Joomla site owners use this feature? Visit the QC Live Forum Community. For private support, bug reports, account-specific entitlement problems, or feature requests, use the QuantaCade support system.