It would be nice to be able to override a single template without keeping a 
private copy of the entire template directory. 

a setup option like

   templatedirs => [ "my/dir", "/usr/share/ikiwiki/templates" ] 

ought to do the trick.

> Now that I look at the source, I see that ikiwiki already falls back to the 
> global dir when it cannot find a template. For me, this is good enough.
> And it is even documented in the man page. Sigh. I guess this could be 
> considered [[done]].  

I have a use case for this, a site composed of blogs and wikis, templates divided in three categories : common, blog and wiki. The only solution I found is maintaining hard links, being able to have multiple template dirs would obviously be better. -- Changaco

> [[plugins/underlay]] used to allow adding extra templatedirs, but Joey
> removed that functionality when he made templates search the wiki's
> own `templates` directory.
>
> You can get a 3-level hierarchy like this:
>
> * instance-specific overrides: $srcdir/templates
> * common to the entire site: a directory that is the value of all
>   instances' `templatedir` parameters
> * common to every ikiwiki in the world: /usr/share/ikiwiki/templates
>   (implicitly searched)
>
> (by "instance" I mean an instance of ikiwiki - a .setup file, basically.)
>
> For a more complex hierarchy you'd need the old [[plugins/underlay]]
> functionality, i.e. you'd need to (ask Joey to) revert the patch that
> removed it. For instance, if anyone has a hierarchy like this, then
> they need the old functionality back in order to split the template
> search path for the things marked `(???)`:
>
>     every ikiwiki in the world (/usr/share/ikiwiki/templates)
>     \--- your site (???)
>         \--- your blogs (???)
>              \--- travel blog ($srcdir/templates)
>              \--- code blog ($srcdir/templates)
>         \--- your wikis (???)
>              \--- travel wiki ($srcdir/templates)
>              \--- code wiki ($srcdir/templates)
>
> This looks pretty hypothetical to me, though...
> --[[smcv]]

>> The reason I removed it is because the same functionality of having
>> multiple template directories is still present. Just put them in 
>> the templates/ subdirectory of multiple underlay directories instead.
>> --[[Joey]]

>>>Thanks, I didn't realize this was possible. Problem solved. -- Changaco

>>>> We can consider this [[done]], then. For reference, the solution
>>>> to the hierarchy I mentioned above would be:
>>>>
>>>>     all your sites have $your_underlay as an underlay
>>>>
>>>>     the blogs and wikis all have $blog_underlay or $wiki_underlay
>>>>     (as appropriate) as a higher priority underlay
>>>>
>>>>     every ikiwiki in the world (/usr/share/ikiwiki/templates)
>>>>     \--- your site ($your_underlay/templates, or templatedir)
>>>>         \--- your blogs ($blog_underlay/templates)
>>>>              \--- travel blog ($srcdir/templates)
>>>>              \--- code blog ($srcdir/templates)
>>>>         \--- your wikis ($wiki_underlay/templates)
>>>>              \--- travel wiki ($srcdir/templates)
>>>>              \--- code wiki ($srcdir/templates)
>>>>
>>>> --[[smcv]]