summaryrefslogtreecommitdiff
path: root/includes/Categoryfinder.php
diff options
context:
space:
mode:
authorPierre Schmitz <pierre@archlinux.de>2006-10-11 18:12:39 +0000
committerPierre Schmitz <pierre@archlinux.de>2006-10-11 18:12:39 +0000
commit183851b06bd6c52f3cae5375f433da720d410447 (patch)
treea477257decbf3360127f6739c2f9d0ec57a03d39 /includes/Categoryfinder.php
MediaWiki 1.7.1 wiederhergestellt
Diffstat (limited to 'includes/Categoryfinder.php')
-rw-r--r--includes/Categoryfinder.php191
1 files changed, 191 insertions, 0 deletions
diff --git a/includes/Categoryfinder.php b/includes/Categoryfinder.php
new file mode 100644
index 00000000..a8cdf3ce
--- /dev/null
+++ b/includes/Categoryfinder.php
@@ -0,0 +1,191 @@
+<?php
+/*
+The "Categoryfinder" class takes a list of articles, creates an internal representation of all their parent
+categories (as well as parents of parents etc.). From this representation, it determines which of these articles
+are in one or all of a given subset of categories.
+
+Example use :
+
+ # Determines wether the article with the page_id 12345 is in both
+ # "Category 1" and "Category 2" or their subcategories, respectively
+
+ $cf = new Categoryfinder ;
+ $cf->seed (
+ array ( 12345 ) ,
+ array ( "Category 1","Category 2" ) ,
+ "AND"
+ ) ;
+ $a = $cf->run() ;
+ print implode ( "," , $a ) ;
+
+*/
+
+
+class Categoryfinder {
+
+ var $articles = array () ; # The original article IDs passed to the seed function
+ var $deadend = array () ; # Array of DBKEY category names for categories that don't have a page
+ var $parents = array () ; # Array of [ID => array()]
+ var $next = array () ; # Array of article/category IDs
+ var $targets = array () ; # Array of DBKEY category names
+ var $name2id = array () ;
+ var $mode ; # "AND" or "OR"
+ var $dbr ; # Read-DB slave
+
+ /**
+ * Constructor (currently empty).
+ */
+ function Categoryfinder () {
+ }
+
+ /**
+ * Initializes the instance. Do this prior to calling run().
+ * @param $article_ids Array of article IDs
+ * @param $categories FIXME
+ * @param $mode String: FIXME, default 'AND'.
+ */
+ function seed ( $article_ids , $categories , $mode = "AND" ) {
+ $this->articles = $article_ids ;
+ $this->next = $article_ids ;
+ $this->mode = $mode ;
+
+ # Set the list of target categories; convert them to DBKEY form first
+ $this->targets = array () ;
+ foreach ( $categories AS $c ) {
+ $ct = Title::newFromText ( $c , NS_CATEGORY ) ;
+ $c = $ct->getDBkey () ;
+ $this->targets[$c] = $c ;
+ }
+ }
+
+ /**
+ * Iterates through the parent tree starting with the seed values,
+ * then checks the articles if they match the conditions
+ @return array of page_ids (those given to seed() that match the conditions)
+ */
+ function run () {
+ $this->dbr =& wfGetDB( DB_SLAVE );
+ while ( count ( $this->next ) > 0 ) {
+ $this->scan_next_layer () ;
+ }
+
+ # Now check if this applies to the individual articles
+ $ret = array () ;
+ foreach ( $this->articles AS $article ) {
+ $conds = $this->targets ;
+ if ( $this->check ( $article , $conds ) ) {
+ # Matches the conditions
+ $ret[] = $article ;
+ }
+ }
+ return $ret ;
+ }
+
+ /**
+ * This functions recurses through the parent representation, trying to match the conditions
+ @param $id The article/category to check
+ @param $conds The array of categories to match
+ @return bool Does this match the conditions?
+ */
+ function check ( $id , &$conds ) {
+ # Shortcut (runtime paranoia): No contitions=all matched
+ if ( count ( $conds ) == 0 ) return true ;
+
+ if ( !isset ( $this->parents[$id] ) ) return false ;
+
+ # iterate through the parents
+ foreach ( $this->parents[$id] AS $p ) {
+ $pname = $p->cl_to ;
+
+ # Is this a condition?
+ if ( isset ( $conds[$pname] ) ) {
+ # This key is in the category list!
+ if ( $this->mode == "OR" ) {
+ # One found, that's enough!
+ $conds = array () ;
+ return true ;
+ } else {
+ # Assuming "AND" as default
+ unset ( $conds[$pname] ) ;
+ if ( count ( $conds ) == 0 ) {
+ # All conditions met, done
+ return true ;
+ }
+ }
+ }
+
+ # Not done yet, try sub-parents
+ if ( !isset ( $this->name2id[$pname] ) ) {
+ # No sub-parent
+ continue ;
+ }
+ $done = $this->check ( $this->name2id[$pname] , $conds ) ;
+ if ( $done OR count ( $conds ) == 0 ) {
+ # Subparents have done it!
+ return true ;
+ }
+ }
+ return false ;
+ }
+
+ /**
+ * Scans a "parent layer" of the articles/categories in $this->next
+ */
+ function scan_next_layer () {
+ $fname = "Categoryfinder::scan_next_layer" ;
+
+ # Find all parents of the article currently in $this->next
+ $layer = array () ;
+ $res = $this->dbr->select(
+ /* FROM */ 'categorylinks',
+ /* SELECT */ '*',
+ /* WHERE */ array( 'cl_from' => $this->next ),
+ $fname."-1"
+ );
+ while ( $o = $this->dbr->fetchObject( $res ) ) {
+ $k = $o->cl_to ;
+
+ # Update parent tree
+ if ( !isset ( $this->parents[$o->cl_from] ) ) {
+ $this->parents[$o->cl_from] = array () ;
+ }
+ $this->parents[$o->cl_from][$k] = $o ;
+
+ # Ignore those we already have
+ if ( in_array ( $k , $this->deadend ) ) continue ;
+ if ( isset ( $this->name2id[$k] ) ) continue ;
+
+ # Hey, new category!
+ $layer[$k] = $k ;
+ }
+ $this->dbr->freeResult( $res ) ;
+
+ $this->next = array() ;
+
+ # Find the IDs of all category pages in $layer, if they exist
+ if ( count ( $layer ) > 0 ) {
+ $res = $this->dbr->select(
+ /* FROM */ 'page',
+ /* SELECT */ 'page_id,page_title',
+ /* WHERE */ array( 'page_namespace' => NS_CATEGORY , 'page_title' => $layer ),
+ $fname."-2"
+ );
+ while ( $o = $this->dbr->fetchObject( $res ) ) {
+ $id = $o->page_id ;
+ $name = $o->page_title ;
+ $this->name2id[$name] = $id ;
+ $this->next[] = $id ;
+ unset ( $layer[$name] ) ;
+ }
+ $this->dbr->freeResult( $res ) ;
+ }
+
+ # Mark dead ends
+ foreach ( $layer AS $v ) {
+ $this->deadend[$v] = $v ;
+ }
+ }
+
+} # END OF CLASS "Categoryfinder"
+
+?>