X-Git-Url: http://git.vanrenterghem.biz/git.ikiwiki.info.git/blobdiff_plain/d2b1264546fa412db8c1591bc8bb14aba04b960d..decb7051f6436aedfd0e9de934d149d9c5b22b36:/doc/todo/allow_site-wide_meta_definitions.mdwn?ds=sidebyside diff --git a/doc/todo/allow_site-wide_meta_definitions.mdwn b/doc/todo/allow_site-wide_meta_definitions.mdwn index 893498f2c..f548f1a5b 100644 --- a/doc/todo/allow_site-wide_meta_definitions.mdwn +++ b/doc/todo/allow_site-wide_meta_definitions.mdwn @@ -1,56 +1,169 @@ [[!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. -Here's a patch to achieve this (also in the "defaultmeta" branch of -my github ikiwiki fork): - - 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]] + +> 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]] + + + +-- [[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. +>>> (Indeed, this later happened to some extent with the sortas parameters +>>> being added to some metas.) +>>> --[[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? + + + +-- [[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]] +>>>>> Hi — I've written a new patch which I hope addresses the concerns raised +>>>>> with the previous ones. The new approach is to hard-code in `scan()` +>>>>> which of the meta types are supported in the setup file. If one is +>>>>> defined, then `scan()` calls `preprocess()`, as [[smcv]] suggested, +>>>>> rather than stuffing redundant data into ikiwiki's data structures. +>>>>> +>>>>> Two types supported in the setup file have optional arguments: `author` +>>>>> and `title`. These are supported by having special-cased setup keys +>>>>> `meta_author_sortas` and `meta_title_sortas`. Future expansion of the +>>>>> number of supported types, or addition of arguments to existing ones, +>>>>> can similarly be special-cased. +>>>>> +>>>>> The setup data structure is no longer complicated with an +>>>>> array-of-hashes, which means this is suitable for exposing via websetup. +>>>>> `getsetup()` has been adjusted accordingly. +>>>>> +>>>>> The patch can be found at the git branch described above. +>>>>> — [[Jon]] + +>>>>>> I wish I could take pity on you and just merge this, but +>>>>>> AFAICS it still suffers from the memory bloat described above. +>>>>>> Specifically, when `scan` calls `preprocess`, it +>>>>>> stores the metadata in `%pagestate` etc. --[[Joey]] + +>>>>>>> No pity required — but whoops, yes, that was a bit of a mistake +>>>>>>> ☺ I guess I'll have to split the current `preprocess` in half. +>>>>>>> — [[Jon]] + +>>>>>>>> I've been taking another look at this today, as I'm very keen to +>>>>>>>> close various open loops of mine in IkiWiki to move on and do some +>>>>>>>> other stuff. However, I'm not actually *using* this at the moment, +>>>>>>>> so whilst I think it's a good idea, I can't really motivate myself +>>>>>>>> to fix it anymore. I guess for now, this should just rot. — [[Jon]]