[[!tag plugins/meta patch]]
[[!template id=gitbranch branch=jon/defaultmeta author="[[Jon]]"]]
I'd like to define [[plugins/meta]] values to apply across all pages
site-wide unless the pages define their own: default values for meta
definitions essentially.
<snip old patch, see below for latest>
-- [[Jon]]
This doesn't support multiple-argument meta directives like
link=x rel=y, or meta directives with special side-effects like
updated.
The first could be solved (if you care) by a syntax like this:
meta_defaults => [
{ copyright => "© me" },
{ link => "about:blank", rel => "silly", },
]
The second could perhaps be solved by invoking meta::preprocess from within
scan (which might be a simplification anyway), although this is complicated
by the fact that some (but not all!) meta headers are idempotent.
--[[smcv]]
Thanks for your comment. I've revised the patch to use the config syntax
you suggest. I need to perform some more testing to make sure I've
addressed the issues you highlight.
I had to patch part of IkiWiki core, the merge routine in Setup, because
the use of possibly_foolish_untaint was causing the hashrefs at the deep
end of the data structure to be converted into strings. The specific change
I've made may not be acceptable, though -- I'd appreciate someone providing
some feedback on that hunk!
Well, re that hunk, taint checking is currently disabled, but
if the perl bug that disallows it is fixed and it is turned back on,
the hash values will remain tainted, which will probably lead to
problems.
I'm also leery of using such a complex data structure in config.
The websetup plugin would be hard pressed to provide a UI for such a
data structure. (It lacks even UI for a single hash ref yet, let alone
a list.)
Also, it seems sorta wrong to have two so very different syntaxes to
represent the same meta data. A user without a lot of experience will
be hard pressed to map from a directive to this in the setup file.
All of which leads me to think the setup file could just contain
a text that could hold meta directives. Which generalizes really to
a text that contains any directives, and is, perhaps appended to the
top of every page. Which nearly generalizes to the sidebar plugin,
or perhaps something more general than that...
However, excessive generalization is the root of all evil, so
I'm not necessarily saying that's a good idea. Indeed, my memory
concerns below invalidate this idea pretty well. --[[Joey]]
diff --git a/IkiWiki/Plugin/meta.pm b/IkiWiki/Plugin/meta.pm
index 6fe9cda..2f8c098 100644
--- a/IkiWiki/Plugin/meta.pm
+++ b/IkiWiki/Plugin/meta.pm
@@ -13,6 +13,8 @@ sub import {
hook(type => "needsbuild", id => "meta", call => \&needsbuild);
hook(type => "preprocess", id => "meta", call => \&preprocess, scan => 1);
hook(type => "pagetemplate", id => "meta", call => \&pagetemplate);
+ hook(type => "scan", id => "meta", call => \&scan)
+ if $config{"meta_defaults"};
}
sub getsetup () {
@@ -305,6 +307,15 @@ sub match {
}
}
+sub scan() {
+ my %params = @_;
+ my $page = $params{page};
+ foreach my $default (@{$config{"meta_defaults"}}) {
+ preprocess(%$default, page => $page,
+ destpage => $page, preview => 0);
+ }
+}
+
package IkiWiki::PageSpec;
sub match_title ($$;@) {
diff --git a/IkiWiki/Setup.pm b/IkiWiki/Setup.pm
index 8a25ecc..e4d50c9 100644
--- a/IkiWiki/Setup.pm
+++ b/IkiWiki/Setup.pm
@@ -51,7 +51,13 @@ sub merge ($) {
$config{$c}=$setup{$c};
}
else {
- $config{$c}=[map { IkiWiki::possibly_foolish_untaint($_) } @{$setup{$c}}]
+ $config{$c}=[map {
+ if(ref $_ eq 'HASH') {
+ $_
+ } else {
+ IkiWiki::possibly_foolish_untaint($_)
+ }
+ } @{$setup{$c}}];
}
}
elsif (ref $setup{$c} eq 'HASH') {
diff --git a/doc/ikiwiki/directive/meta.mdwn b/doc/ikiwiki/directive/meta.mdwn
index 000f461..8d34ee4 100644
--- a/doc/ikiwiki/directive/meta.mdwn
+++ b/doc/ikiwiki/directive/meta.mdwn
@@ -12,6 +12,16 @@ also specifies some additional sub-parameters.
The field values are treated as HTML entity-escaped text, so you can include
a quote in the text by writing `"` and so on.
+You can also define site-wide defaults for meta values by including them
+in your setup file. The key used is `meta_defaults` and the value is a list
+of hashes, one per meta directive. e.g.:
+
+ meta_defaults = [
+ { copyright => "Copyright 2007 by Joey Hess" },
+ { license => "GPL v2+" },
+ { link => "somepage", rel => "site entrypoint", },
+ ],
+
Supported fields:
* title
-- [[Jon]]
Ok, I've had a bit of a think about this. There are currently 15 supported
meta fields. Of these: title, licence, copyright, author, authorurl,
and robots might make sense to define globally and override on a per-page
basis.
Less so, description (due to its impact on map); openid (why would
someone want more than one URI to act as an openid endpoint to the same
place?); updated. I can almost see why someone might want to set a global
updated value. Almost.
Not useful are permalink, date, stylesheet (you already have a global
stylesheet), link, redir, and guid.
In other words, the limitations of my first patch that [[smcv]] outlined
are only relevant to defined fields that you wouldn't want to specify a
global default for anyway.
I generally agree with this. It is possible that meta would have a new
field added, that takes parameters and make sense to use globally.
--[[Joey]]
Due to this, and the added complexity of the second patch (having to adjust
IkiWiki/Setup.pm), I think the first patch makes more sense. I've thus
reverted to it here.
Is this merge-worthy?
diff --git a/IkiWiki/Plugin/meta.pm b/IkiWiki/Plugin/meta.pm
index b229592..3132257 100644
--- a/IkiWiki/Plugin/meta.pm
+++ b/IkiWiki/Plugin/meta.pm
@@ -13,6 +13,7 @@ sub import {
hook(type => "needsbuild", id => "meta", call => \&needsbuild);
hook(type => "preprocess", id => "meta", call => \&preprocess, scan => 1);
hook(type => "pagetemplate", id => "meta", call => \&pagetemplate);
+ hook(type => "scan", id => "meta", call => \&scan);
}
sub getsetup () {
@@ -302,6 +303,15 @@ sub match {
}
}
+sub scan() {
+ my %params = @_;
+ my $page = $params{page};
+ foreach my $type (map { s/^meta_//; $_ } grep /^meta_/, keys %config) {
+ $pagestate{$page}{meta}{$type} = $config{"meta_$type"}
+ unless defined $pagestate{$page}{meta}{$type};
+ }
+}
+
package IkiWiki::PageSpec;
sub match_title ($$;@) {
diff --git a/doc/ikiwiki/directive/meta.mdwn b/doc/ikiwiki/directive/meta.mdwn
index 000f461..200c4b2 100644
--- a/doc/ikiwiki/directive/meta.mdwn
+++ b/doc/ikiwiki/directive/meta.mdwn
@@ -12,6 +12,12 @@ also specifies some additional sub-parameters.
The field values are treated as HTML entity-escaped text, so you can include
a quote in the text by writing `"` and so on.
+You can also define site-wide defaults for meta values by including them
+in your setup file, e.g.
+
+ meta_copyright => "Copyright 2007 by Joey Hess",
+ meta_license => "GPL v2+",
+
Supported fields:
* title
-- [[Jon]]
Merry Christmas/festive season/happy new year folks. I've been away from
ikiwiki for the break, and now I've returned to watching recentchanges.
Hopefully I'll be back in the mix soon, too. In the meantime, Joey, have
you had a chance to look at this yet? -- [[Jon]]
Ping :) Hi. [[Joey]], would you consider this patch for the next
ikiwiki release? -- [[Jon]]
For this to work with websetup and --dumpsetup, it needs to define the
meta_* settings in the getsetup function.
I think this will be problematic with the current implementation of this
patch. The datatype here is an array of hash references, with each hash
having a variable (and arbitrary) number of key/value pairs. I can't
think of an intuitive way of implementing a way of editing such a
datatype in the web interface, let alone registering the option in
getsetup.
Perhaps a limited set of defined meta values could be exposed via
websetup (the obvious ones: author, copyright, license, etc.) -- [[Jon]]
I also have some concerns about both these patches, since both throw
a lot of redundant data at meta, which then stores it in a very redundant
way. Specifically, meta populates a per-page %metaheaders hash
as well as storing per-page metadata in %pagestate. So, if you have
a wiki with 10 thousand pages, and you add a 1k site-wide license text,
that will bloat the memory usage of ikiwiki by in excess of 2
megabytes. It will also cause ikiwiki to write a similar amount more data
to its state file which has to be loaded back in each
run.
Seems that this could be managed much more efficiently by having
meta special-case the site-wide settings, not store them in these
per-page data structures, and just make them be used if no per-page
metadata of the given type is present. --[[Joey]]
that should be easy enough to do. I will work on a patch. -- [[Jon]]
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