I can show you what my best guesses were, but it would be difficult to remember all the combinations I have gone through, it took hours... :) Here we go:
design:full/my_vehicles_class.tpl (level1)
{* a *}{cache-block keys=$node.node_id subtree_expiry=$node.path_identification_string}
{* b *}{cache-block subtree_expiry=$node.path_identification_string}
{* fetch('content','list/tree', ...) *}
{* display level2 and level3 elements *}
{/cache-block}
I tried two scenarios as well, with level2 and level3 elemenents being published via administration interface and self-prepared 'add group/add brand' content action forms.
Nothing changes, except for the fact that there's a debug error:
Error: eZTemplateCacheFunction::subtreeExpiryCacheDir()
Could not find path_string for 'subtree_expiry' node.
What exactly would be the purpose of it? Should I expect any special characters in the url_alias attribute that may affect the function? In that case, wouldn't it be better to trim its value instead? Otherwise, what would be the point? Just curious :)
Apparently I encountered certain issues with cache-block before, and the code above made it work in those cases. I inspected the PHP code now and what I did was indeed not needed since slashes are trimmed in the PHP template function code to.
Do you have DelayedCacheBlockCleanup=enabled in one of your site.ini overrides? If yes then remove it or use the subtreeexpirycleanup cronjob. Have you enabled view caching? Then you need to disable it for your specific template. Put this at the first line of the template:
That's right, now I remember some former posts concerned with subree_expiry syntax and the slashes. I think I have even tried concatenating the path and the slash... but it didn't work either as far as I remember... :)
I'll let know as soon as I check your latest suggestions. Thanks.