Your IP : 108.162.216.193
<?php
/**
* Recent changes filtering by category.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
/**
* 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 :
* <code>
* # Determines whether 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 );
* </code>
*
*/
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 DatabaseBase
*/
var $dbr; # Read-DB slave
/**
* Constructor (currently empty).
*/
function __construct() {
}
/**
* Initializes the instance. Do this prior to calling run().
* @param $article_ids Array of article IDs
* @param $categories FIXME
* @param string $mode FIXME, default 'AND'.
* @todo FIXME: $categories/$mode
*/
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::makeTitleSafe( NS_CATEGORY, $c );
if ( $ct ) {
$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 int $id The article/category to check
* @param array $conds The array of categories to match
* @param array $path used to check for recursion loops
* @return bool Does this match the conditions?
*/
function check( $id, &$conds, $path = array() ) {
// Check for loops and stop!
if ( in_array( $id, $path ) ) {
return false;
}
$path[] = $id;
# Shortcut (runtime paranoia): No conditions=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, $path );
if ( $done || 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() {
wfProfileIn( __METHOD__ );
# 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 ),
__METHOD__ . '-1'
);
foreach ( $res as $o ) {
$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->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 */ array( 'page_id', 'page_title' ),
/* WHERE */ array( 'page_namespace' => NS_CATEGORY, 'page_title' => $layer ),
__METHOD__ . '-2'
);
foreach ( $res as $o ) {
$id = $o->page_id;
$name = $o->page_title;
$this->name2id[$name] = $id;
$this->next[] = $id;
unset( $layer[$name] );
}
}
# Mark dead ends
foreach ( $layer as $v ) {
$this->deadend[$v] = $v;
}
wfProfileOut( __METHOD__ );
}
}