[[!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. -- [[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]]