4 * The "Categoryfinder" class takes a list of articles, creates an internal
5 * representation of all their parent categories (as well as parents of
6 * parents etc.). From this representation, it determines which of these
7 * articles are in one or all of a given subset of categories.
11 * # Determines whether the article with the page_id 12345 is in both
12 * # "Category 1" and "Category 2" or their subcategories, respectively
14 * $cf = new Categoryfinder ;
17 * array ( "Category 1","Category 2" ) ,
21 * print implode ( "," , $a ) ;
25 class Categoryfinder
{
27 var $articles = array () ; # The original article IDs passed to the seed function
28 var $deadend = array () ; # Array of DBKEY category names for categories that don't have a page
29 var $parents = array () ; # Array of [ID => array()]
30 var $next = array () ; # Array of article/category IDs
31 var $targets = array () ; # Array of DBKEY category names
32 var $name2id = array () ;
33 var $mode ; # "AND" or "OR"
34 var $dbr ; # Read-DB slave
37 * Constructor (currently empty).
39 function __construct() {
43 * Initializes the instance. Do this prior to calling run().
44 * @param $article_ids Array of article IDs
45 * @param $categories FIXME
46 * @param $mode String: FIXME, default 'AND'.
48 function seed ( $article_ids , $categories , $mode = "AND" ) {
49 $this->articles
= $article_ids ;
50 $this->next
= $article_ids ;
53 # Set the list of target categories; convert them to DBKEY form first
54 $this->targets
= array () ;
55 foreach ( $categories AS $c ) {
56 $ct = Title
::makeTitleSafe( NS_CATEGORY
, $c );
59 $this->targets
[$c] = $c;
65 * Iterates through the parent tree starting with the seed values,
66 * then checks the articles if they match the conditions
67 * @return array of page_ids (those given to seed() that match the conditions)
70 $this->dbr
= wfGetDB( DB_SLAVE
);
71 while ( count ( $this->next
) > 0 ) {
72 $this->scan_next_layer () ;
75 # Now check if this applies to the individual articles
77 foreach ( $this->articles
AS $article ) {
78 $conds = $this->targets
;
79 if ( $this->check ( $article , $conds ) ) {
80 # Matches the conditions
88 * This functions recurses through the parent representation, trying to match the conditions
89 * @param $id The article/category to check
90 * @param $conds The array of categories to match
91 * @param $path used to check for recursion loops
92 * @return bool Does this match the conditions?
94 function check ( $id , &$conds, $path=array() ) {
95 // Check for loops and stop!
96 if( in_array( $id, $path ) )
100 # Shortcut (runtime paranoia): No contitions=all matched
101 if ( count ( $conds ) == 0 ) return true ;
103 if ( !isset ( $this->parents
[$id] ) ) return false ;
105 # iterate through the parents
106 foreach ( $this->parents
[$id] AS $p ) {
109 # Is this a condition?
110 if ( isset ( $conds[$pname] ) ) {
111 # This key is in the category list!
112 if ( $this->mode
== "OR" ) {
113 # One found, that's enough!
117 # Assuming "AND" as default
118 unset ( $conds[$pname] ) ;
119 if ( count ( $conds ) == 0 ) {
120 # All conditions met, done
126 # Not done yet, try sub-parents
127 if ( !isset ( $this->name2id
[$pname] ) ) {
131 $done = $this->check ( $this->name2id
[$pname] , $conds, $path );
132 if ( $done OR count ( $conds ) == 0 ) {
133 # Subparents have done it!
141 * Scans a "parent layer" of the articles/categories in $this->next
143 function scan_next_layer () {
144 $fname = "Categoryfinder::scan_next_layer" ;
146 # Find all parents of the article currently in $this->next
148 $res = $this->dbr
->select(
149 /* FROM */ 'categorylinks',
151 /* WHERE */ array( 'cl_from' => $this->next
),
154 while ( $o = $this->dbr
->fetchObject( $res ) ) {
158 if ( !isset ( $this->parents
[$o->cl_from
] ) ) {
159 $this->parents
[$o->cl_from
] = array () ;
161 $this->parents
[$o->cl_from
][$k] = $o ;
163 # Ignore those we already have
164 if ( in_array ( $k , $this->deadend
) ) continue ;
165 if ( isset ( $this->name2id
[$k] ) ) continue ;
170 $this->dbr
->freeResult( $res ) ;
172 $this->next
= array() ;
174 # Find the IDs of all category pages in $layer, if they exist
175 if ( count ( $layer ) > 0 ) {
176 $res = $this->dbr
->select(
178 /* SELECT */ 'page_id,page_title',
179 /* WHERE */ array( 'page_namespace' => NS_CATEGORY
, 'page_title' => $layer ),
182 while ( $o = $this->dbr
->fetchObject( $res ) ) {
184 $name = $o->page_title
;
185 $this->name2id
[$name] = $id ;
186 $this->next
[] = $id ;
187 unset ( $layer[$name] ) ;
189 $this->dbr
->freeResult( $res ) ;
193 foreach ( $layer AS $v ) {
194 $this->deadend
[$v] = $v ;
198 } # END OF CLASS "Categoryfinder"