[TYPO3-dev] Suggestions for triggering BE sprite generation

[Steffen Gebert]

Hi,

as some other threads got a little OT, I'd just like to start this one.

How would you implement a sprite generator?

Most important thing is: When will the sprites be generated - or should  
they be generated at all?

Ideas:

dynamic
=======
- creating sprites at the first request, saving them to typo3temp/
- hasing the array of included images (only filenames) to get the cache  
filename
   -> icon changes would require clearing of typo3temp/
- more sophicistic cache calculation: last modified date + file size
   -> overhead for each single request
- saving the generated filename in cache, clearing this entry after  
clearing config cache (or a new BE cache)
- the selected skin has to be incorporated - we shouldn't obstruct the way  
to per-user skins, also multiple simultaneous skins should be possible  
(e.g. one skin which only styles the page tree etc.)
   -> one file per skin? generating *one* user-specific file, based on his  
skin selection and merging all together

static
======
- core brings a static sprite for t3skin (do we use an online generator?  
do we use a PSD? BE module to generate them?)
- extensions also bring their own (don't know, if this really needed - are  
there SO many icons?)
- extdeveval or similar to create sprite+css for extensions
- NOT saved to typo3temp
- long browser cache life-times? how can we trigger reload of the file?

Further thinking:
- currently all icons only 16x16
- skin with bigger icon sizes?
- does extensions have to ship multiple sizes?
- *should* they be able to ship one bigger icon (64x64?), which is scaled?


Please remember: We don't kneed/want the jack of all trades device!
It should be possible to implement it in a few hours. Otherwise some of  
you have to help out!

Steffen