~~NOCACHE~~
====== PlWiki 1.0 - Plugin API ======

[[.:plwiki1ex|Examples available here]]


**IMPORTANT:**

This code should be placed on every page using PlWiki plugin:
<code> ~~NOCACHE~~ </code>
 
===== Prolog Code in Loki =====

The simplest use case. Without cache. Only process knowledge between "pl" tags. 

<code loki>
<pl goal="woman(X),write(X),nl,fail">
woman(kate).
man(john).
</pl>
</code>

__Result__:\\
<pl goal="woman(X),write(X),nl,fail">
woman(kate).
man(john).
</pl>


More interesting use case: adding knowledge to the page: 

<code loki>
<pl cache="true">
man(jack).
man(jim).
</pl>
</code>

<pl cache="true">
man(jack).
man(jim).
</pl>


Now when we have prolog code associated with DokuWiki page, we can "query" selected scope or Wiki page. Scope accepts POSIX Regular Expressions.

<code loki>
<pl goal="man(X),write(X),nl,fail"  scope="docs:plwiki1ex" >
%
% Prolog code may be placed here but it is not necessairly.
%
</pl>
</code>

__Result__:\\
<pl goal="man(X),write(X),nl,fail"  scope="docs:plwiki1ex" >
%
% Prolog code may be placed here but it is not necessarily.
%
</pl>

===== Prolog interface =====

Loki plugin also contains loki.pl prolog script, which allows to query knowledge gathered in Loki from Prolog.

We can list all predicates in selected scope:
<code loki>
<pl goal="consult('lib/plugins/loki/loki.pl'),wikiconsult('docs/plwiki1api'),list."></pl>
</code>

__Result__:\\
<pl goal="consult('lib/plugins/loki/loki.pl'),wikiconsult('docs/plwiki1api'),list."></pl>


We can also list informations about selected predicate.

<code loki>
<pl goal="consult('lib/plugins/loki/loki.pl'),wikiconsult('docs/plwiki1api'),list(man)."></pl>
</code>

__Result__:\\
<pl goal="consult('lib/plugins/loki/loki.pl'),wikiconsult('docs/plwiki1api'),list(man)."></pl>


===== Categories, Relations, Attributes =====
[[http://semantic-mediawiki.org/wiki/Semantic_MediaWiki|Semantic MediaWiki]] syntax is also supported, there are some methods of semantic annotation:

  * categories - a simple form of annotation that allows users to classify pages. To state that article (Wiki page) belongs to the category "category1" we have to write <code smw>[[category:category1]]</code> 

  * relations - there is a possibility to describe relationships between two Wiki pages. For example there is a relation "capital_of" between "cities:warsaw" and "coutries:poland". To express this we have to just edit the page "countries:warsaw" and add <code smw>[[capital of::countries:poland]]</code> 

  * attributes - allows to specify relationships of Wiki pages to things that are not Wiki pages. For example, one can state that Wiki page "namespace:page" was created at April 22 2009 by writing <code smw>[[created:=April 22 2009]]</code>

  * In addition to this users can search for articles using a simple query language that was developed based on the known syntax of the Wiki. For example: <code smw>{{#ask: [[category:cities]] [[capital_of::countries:poland]]}}</code>