[pmwiki-users] RFC: Indexing categories and links
5ko at 5ko.fr
Wed Mar 3 13:58:36 CST 2010
Many times, there have been requests about improving the way Pagelists with
Backlinks are generated, particularly about the category feature.
There are two different markups, [[Category/Name]] and [[!Name]] which both
create a link to the page Category.Name, and pages both are currently
displayed in the above pagelist.
Authors have asked for the possibility to list only pages containing the
category link [[!Name]] but not containing the regular link [[Category/Name]].
Category links are stored in a special attribute in the page file, and also in
a special file .pageindex to speed up the searches, in the form "Category.Name
We have come up with an idea to add both strings "Category.Name" and "!Name"
to the page attribute and to the .pageindex file.
* If a page contains a link [[!Name]], both "Category.Name" and "!Name" are
stored in the indexes.
* If a page contains a link [[Category/Name]], only "Category.Name" is
stored in the indexes.
* A pagelist with link=Category.Name will find all pages linking to
Category.Name, both [[Category/Name]] and [[!Name]], like now.
No wikis will break because of the change.
* A pagelist with link=!Name will find only pages containing [[!Name]], which
is new. Only newly created (:pagelist link=!Name:) will display these pages.
This way, with a few changes of 3 or 4 core functions, it is possible to add
the much requested feature, and to stay backwards compatible with all current
installations. (WikiAdmins may need to remove the wiki.d/.pageindex file after
upgrading to let PmWiki reindex the site.)
So my first question is should we do this change?
Another feature was suggested by Peter Bowers. We can have globally defined
link prefixes like :
! for Category
~ for Profiles
and others. These link prefixes can be defined in config.php and then used in
the wiki, like for example
[[:Name]] = [[Projects/Name]] or
[[@Name]] = [[Tags/Name]] or
[[+Name]] = [[ToDo/Name]] etc.
If we change the current !Category and ~Profiles links to be handled by the
same mechanism as [[regular links]], adding more prefixes will be very easy
for wiki admins. PmWiki will likely not have new link prefixes, but individual
wikis could add them with such line in config.php:
$LinkPrefixGroup['@'] = 'Tags';
Using a global way of dealing with links will fix some bugs we've had for a
"[[!My category | Alternative text ]]" doesn't work in 2.2.14
"[[!My category |+]]" doesn't work in 2.2.14
"[[!My category]]suffix" doesn't work in 2.2.14
So my second question is should we enable this link-prefix feature?
If your answer is yes, I'll invite you to download the latest "pre-release"
code from Subversion, test the new features and report any problems which we
haven't discovered yet.
Note, these changes in Subversion are for testing and discussing purposes, so
don't build upon them. We (especially Pm) may conclude that we shouldn't
release them at this moment.
P.S. The current proposition will not yet allow a pagelist with
link=Page1,Page2 or link=Page1,-Page2 to list pages to 2 or more categories --
which would require more substantial changes to the Pagelist functions which
should be done more carfully, not today.
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