3 * The "Categoryfinder" class takes a list of articles, creates an internal
4 * representation of all their parent categories (as well as parents of
5 * parents etc.). From this representation, it determines which of these
6 * articles are in one or all of a given subset of categories.
10 * # Determines whether the article with the page_id 12345 is in both
11 * # "Category 1" and "Category 2" or their subcategories, respectively
13 * $cf = new Categoryfinder ;
16 * array ( "Category 1","Category 2" ) ,
20 * print implode ( "," , $a ) ;
24 class Categoryfinder {
25 var $articles = array(); # The original article IDs passed to the seed function
26 var $deadend = array(); # Array of DBKEY category names for categories that don't have a page
27 var $parents = array(); # Array of [ID => array()]
28 var $next = array(); # Array of article/category IDs
29 var $targets = array(); # Array of DBKEY category names
30 var $name2id = array();
31 var $mode; # "AND" or "OR"
32 var $dbr; # Read-DB slave
35 * Constructor (currently empty).
37 function __construct() {
41 * Initializes the instance. Do this prior to calling run().
42 * @param $article_ids Array of article IDs
43 * @param $categories FIXME
44 * @param $mode String: FIXME, default 'AND'.
46 function seed( $article_ids, $categories, $mode = "AND" ) {
47 $this->articles = $article_ids;
48 $this->next = $article_ids;
51 # Set the list of target categories; convert them to DBKEY form first
52 $this->targets = array();
53 foreach ( $categories as $c ) {
54 $ct = Title::makeTitleSafe( NS_CATEGORY, $c );
57 $this->targets[$c] = $c;
63 * Iterates through the parent tree starting with the seed values,
64 * then checks the articles if they match the conditions
65 * @return array of page_ids (those given to seed() that match the conditions)
68 $this->dbr = wfGetDB( DB_SLAVE );
69 while ( count ( $this->next ) > 0 ) {
70 $this->scan_next_layer();
73 # Now check if this applies to the individual articles
76 foreach ( $this->articles as $article ) {
77 $conds = $this->targets;
78 if ( $this->check( $article, $conds ) ) {
79 # Matches the conditions
87 * This functions recurses through the parent representation, trying to match the conditions
88 * @param $id The article/category to check
89 * @param $conds The array of categories to match
90 * @param $path used to check for recursion loops
91 * @return bool Does this match the conditions?
93 function check( $id , &$conds, $path = array() ) {
94 // Check for loops and stop!
95 if ( in_array( $id, $path ) ) {
101 # Shortcut (runtime paranoia): No contitions=all matched
102 if ( count( $conds ) == 0 ) {
106 if ( !isset( $this->parents[$id] ) ) {
110 # iterate through the parents
111 foreach ( $this->parents[$id] as $p ) {
114 # Is this a condition?
115 if ( isset( $conds[$pname] ) ) {
116 # This key is in the category list!
117 if ( $this->mode == "OR" ) {
118 # One found, that's enough!
122 # Assuming "AND" as default
123 unset( $conds[$pname] ) ;
124 if ( count( $conds ) == 0 ) {
125 # All conditions met, done
131 # Not done yet, try sub-parents
132 if ( !isset( $this->name2id[$pname] ) ) {
136 $done = $this->check( $this->name2id[$pname], $conds, $path );
137 if ( $done || count( $conds ) == 0 ) {
138 # Subparents have done it!
146 * Scans a "parent layer" of the articles/categories in $this->next
148 function scan_next_layer() {
149 # Find all parents of the article currently in $this->next
151 $res = $this->dbr->select(
152 /* FROM */ 'categorylinks',
154 /* WHERE */ array( 'cl_from' => $this->next ),
157 while ( $o = $this->dbr->fetchObject( $res ) ) {
161 if ( !isset( $this->parents[$o->cl_from] ) ) {
162 $this->parents[$o->cl_from] = array();
164 $this->parents[$o->cl_from][$k] = $o;
166 # Ignore those we already have
167 if ( in_array ( $k , $this->deadend ) ) continue;
169 if ( isset ( $this->name2id[$k] ) ) continue;
175 $this->next = array();
177 # Find the IDs of all category pages in $layer, if they exist
178 if ( count ( $layer ) > 0 ) {
179 $res = $this->dbr->select(
181 /* SELECT */ array( 'page_id', 'page_title' ),
182 /* WHERE */ array( 'page_namespace' => NS_CATEGORY , 'page_title' => $layer ),
185 while ( $o = $this->dbr->fetchObject( $res ) ) {
187 $name = $o->page_title;
188 $this->name2id[$name] = $id;
190 unset( $layer[$name] );
195 foreach ( $layer as $v ) {
196 $this->deadend[$v] = $v;