[[!template id=gitbranch branch=smcv/sort-hooks author="[[Simon_McVittie|smcv]]"]]
[[!tag patch]]
The available [[ikiwiki/pagespec/sorting]] methods are currently hard-coded in
IkiWiki.pm, making it difficult to add any extra sorting mechanisms. I've
prepared a branch which adds 'sort' as a hook type and uses it to implement a
new meta_title
sort type.
Someone could use this hook to make \[[!inline sort=title]]
prefer the meta
title over the page name, but for compatibility, I'm not going to (I do wonder
whether it would be worth making sort=name an alias for the current sort=title,
and changing the meaning of sort=title in 4.0, though).
Gitweb:
http://git.pseudorandom.co.uk/smcv/ikiwiki.git?a=shortlog;h=refs/heads/sort-hooks
I briefly tried to turn all the current sort types into hook functions, and
have some of them pre-registered, but decided that probably wasn't a good idea.
That earlier version of the branch is also available for comparison:
http://git.pseudorandom.co.uk/smcv/ikiwiki.git?a=shortlog;h=refs/heads/sort-hooks-excessive
(The older version is untested, and probably doesn't really work as-is - I
misunderstood the details of how the built-in function sort
works when using
$a
and $b
. The newer version has been tested, and has a regression test for
its core functionality.)
This hook isn't (yet) sufficient to implement [[plugins/contrib/report]]'s
NIH'd sorting mechanisms:
-
report
can sort by any [[plugins/contrib/field]], whereas this one has a
finite number of hooks: if the field
plugin's functionality is desirable,
perhaps parameterized sort mechanisms similar to pagespec match functions
would be useful? Then the field
plugin could register
hook(type => "sort", id => "field")
and you could have
\[[!inline ... sort="field(Mood)"]]
or something?
-
report
can sort by multiple criteria, with independent direction-changing:
if this is desirable, perhaps pagespec_match_list
could be enhanced to
interpret sort="x -y z(w)"
as sorting by (pseudocode)
{ $cmp_x->($a, $b) || (-$cmp_y->($a, $b)) || $cmp_z->($a, $b, "w") }
?
I wonder if IkiWiki would benefit from the concept of a "sortspec", like a [[ikiwiki/PageSpec]] but dedicated to sorting lists of pages rather than defining lists of pages? Rather than defining a sort-hook, define a SortSpec class, and enable people to add their own sort methods as functions defined inside that class, similarly to the way they can add their own pagespec definitions. --[[KathrynAndersen]]
Documentation extracted from the branch
sort hook (added to [[plugins/write]])
hook(type => "sort", id => "foo", call => \&sort_by_foo);
This hook adds an additional [[ikiwiki/pagespec/sorting]] order or overrides
an existing one. The callback is given two page names as arguments, and
returns negative, zero or positive if the first page should come before,
close to (i.e. undefined order), or after the second page.
For instance, the built-in title
sort order could be reimplemented as
sub sort_by_title {
pagetitle(basename($_[0])) cmp pagetitle(basename($_[1]));
}
meta_title sort order (conditionally added to [[ikiwiki/pagespec/sorting]])
meta_title
- Order according to the \[[!meta title="foo" sort="bar"]]
or \[[!meta title="foo"]]
[[ikiwiki/directive]], or the page name if no
full title was set.
meta title sort parameter (added to [[ikiwiki/directive/meta]])
An optional sort
parameter will be used preferentially when
[[ikiwiki/pagespec/sorting]] by meta_title
:
\[[!meta title="The Beatles" sort="Beatles, The"]]
\[[!meta title="David Bowie" sort="Bowie, David"]]