vBulletin LTS

Image Cache
Mod Version: 1.0.3.0, by y2ksw

Y2K Software Image Cache

Compatible at least with vBulletin 3.5.4 and 3.6.4

Please click here for the product Import External Images for vBulletin 4

This product caches images from external sites to a local board folder (including signatures) located at:

http://www.domain.tld/[forum/]imgcache

Installation

1. Please create at your vBulletin board directory a folder called: imgcache and give it the following access rights: CHMOD 777 (read/write/modify to all users)
2. Create an empty index.html file in this folder to avoid file exploring and direct download on some systems.
3. Copy the y2kswimgcache.php file to your vBulletin board (forum home) directory.
4. Close your forum temporarily to the public.
5. Install the product product-y2kswimagecache.xml to your board (allow overwrite if already present).
   The installer will add a table called '[prefix]y2ksw_imgcache' with one field (int ID AUTOINCREMENT) to your board database.
   Please note: Although the uninstaller is provided, it is commented out. By removing the table, and reinstalling the plugin later, the cached images would be overwritten, because of the field counter restarting from 1.
   By leaving the table in your database, you may reinstall the plugin later without collision problems.
6. Test the product: New thread, reply, edit. If errors occur (or white pages), make sure your imgcache/ folder has the required access rights.
7. Reopen your forum to the public.
8. DONE!

How it works

When a board user opens a new thread or message, or edits an existing one (all advanced, quick-reply and ajax), and pastes an image from all but the local cache directory (or by copy and paste, or by specifying [IMG] tags), upon submission the image is read from the external url and written to the local (server) image cache folder.
This avoids to show a placeholder image when the source link is dead or temporarily unavailable.

The link to the image is accordingly replaced.

The script scans first all image references and creates a table of unique images in the current message. It creates a new database table entry in y2ksw_imgcache for each image, reads the new ID and creates a sequence of new images for each url it happens to be readable, and creates for each successful read an imgcache/<id>.png file.

After this sequence, the files are cached locally and may disappear from their sources without leaving an unreferenced image pointer at the local board.

Known bugs

When an image link contains dynamic data, vBulletin would show the image in preview, but change also the IMG tags to URL.
This causes to loose the reference and the plugin will not attempt to recover. A possible solution is to allow dynamic contents for IMG tags on your board.

Version history

1.0.3.0 2007-08-19 Repaired browser (IE 7) issue for images of a different file extension than the officially recognized types. For this issue, newly cached files have now the *.png extension.
1.0.2.0 2006-08-27 Image caching of signatures ([IMG] tags for signatures must be enabled); added a donation button inside readme.htm for specific user requests, which will help us to keep this product always up-to-date.
1.0.1.2 2006-08-07 Release changes for vbulletin.org
1.0.1.1 2006-08-06 Image size verification to avoid caching of invalid images
1.0.1.0 2006-07-17 Collision-free unique cache ID's
1.0.0.0 2006-07-17 Product creation