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 foreach ( $res as $o ) {
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
) ) {
171 if ( isset( $this->name2id
[$k] ) ) {
179 $this->next
= array();
181 # Find the IDs of all category pages in $layer, if they exist
182 if ( count( $layer ) > 0 ) {
183 $res = $this->dbr
->select(
185 /* SELECT */ array( 'page_id', 'page_title' ),
186 /* WHERE */ array( 'page_namespace' => NS_CATEGORY
, 'page_title' => $layer ),
189 foreach ( $res as $o ) {
191 $name = $o->page_title
;
192 $this->name2id
[$name] = $id;
194 unset( $layer[$name] );
199 foreach ( $layer as $v ) {
200 $this->deadend
[$v] = $v;