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Diffstat (limited to 'doc/todo/dependency_types.mdwn')
| -rw-r--r-- | doc/todo/dependency_types.mdwn | 43 |
1 files changed, 37 insertions, 6 deletions
diff --git a/doc/todo/dependency_types.mdwn b/doc/todo/dependency_types.mdwn index 215a65c8a..58b5ee955 100644 --- a/doc/todo/dependency_types.mdwn +++ b/doc/todo/dependency_types.mdwn @@ -10,9 +10,9 @@ whenever a matching dependency is added, removed, or *modified*. But a great many things don't care about the modification case, and often cause unnecessary page rebuilds: -* meta only cares if the pages are added or removed. Content change does +* map only cares if the pages are added or removed. Content change does not matter (unless show=title is used). -* brokenlinks, orphans, pagecount, ditto +* brokenlinks, orphans, pagecount, ditto (generally) * inline in archive mode cares about page title, author changing, but not content. (Ditto for meta with show=title.) * Causes extra work when solving the [[bugs/transitive_dependencies]] @@ -109,9 +109,6 @@ I propose the following. --[[Joey]] * `add_depends` defaults to adding a regular ("full") dependency, as before. (So nothing breaks.) * `add_depends($page, $spec, content => 0)` adds an contentless dependency. -* Contentless dependencies are stored in `%depends_contentless` and - `%depends_contentless_simple`, which are stored in the index similarly - to the existing hashes. * `refresh` only looks at added/removed pages when resolving contentless dependencies. @@ -121,5 +118,39 @@ to the two types he talks about above, but I hope are close enough that they can be used. This doesn't deal with the stuff that only depend on the metadata of a -page, as collected in the scan pass, changing. But it does leave a window +page, as collected in the scan pass, changing. But it does leave a window open for adding such a dependency type later. + +---- + +I implemented the above in a branch. +[[!template id=gitbranch branch=origin/dependency-types author="[[joey]]"]] + +Then I found some problems: + +* Something simple like pagecount, that seems like it could use a + contentless dependency, can have a pagespec that uses metadata, like + `author()` or `copyright()`. +* pagestats, orphans and brokenlinks cannot use contentless dependencies + because they need to update when links change. + +Now I'm thinking about having a contentless dependency look at page +metadata, and fire if the metadata changes. And it seems links should +either be included in that, or there should be a way to make a dependency +that fires when a page's links change. (And what about backlinks?) + +It's easy to see when a page's links change, since there is `%oldlinks`. +To see when metadata is changed is harder, since it's stored in the +pagestate by the meta plugin. + +Quick alternative: Make add_depends look at the pagespec. Ie, if it +is a simple page name, or a glob, we know a contentless dependency +can be valid. If's more complex, convert the dependency from +contentless to full. + +There is a lot to dislike about this method. Its parsing of the +pagespec, as currently implemented, does not let plugins add new types of +pagespecs that are contentless. Its pagespec parsing is also subject to +false negatives (though these should be somewhat rare, and no false +positives). Still, it does work, and it makes things like simple maps and +pagecounts much more efficient. |