Википедия использует «карту сайта HTML» для ссылки на каждую страницу контента. Огромное количество страниц нужно разбить на множество групп, чтобы на каждой странице было максимум около. 100 ссылок, конечно.
Вот как это делает Википедия:
Специально: Все страницы
Весь список статей разделен на несколько больших групп, каждая из которых определяется их первым и последним словом:
- «Рейтинг ААА» для «раннего усыновителя»
- "земля" до "плача"
- от "низкого" до "священника"
- ...
Когда вы нажимаете одну категорию, этот диапазон (например, «земля» - «плач») также разделяется. Эта процедура повторяется до тех пор, пока текущий диапазон не включает только ок. 100 статей, чтобы их можно было отображать.
Мне очень нравится этот подход к спискам ссылок, который сводит к минимуму количество кликов, необходимых для перехода к любой статье.
Как автоматически создать такой список статей?
Поэтому мой вопрос заключается в том, как можно автоматически создать такую страницу индекса, которая позволяет переходить по небольшим категориям, пока количество содержащихся статей не станет достаточно маленьким для их отображения.
Представьте, что дан массив всех названий статей, как бы вы начали программировать индекс с автоматическим разделением по категориям?
Array('AAA rating', 'abdicate', ..., 'zero', 'zoo')
Было бы здорово, если бы вы могли мне помочь. Мне не нужно идеальное решение, но полезный подход, конечно. Заранее большое спасибо!
Редактировать: Теперь нашли часть в программном обеспечении Википедии (MediaWiki):
<?php
/**
* Implements Special:Allpages
*
* 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
* @ingroup SpecialPage
*/
/**
* Implements Special:Allpages
*
* @ingroup SpecialPage
*/
class SpecialAllpages extends IncludableSpecialPage {
/**
* Maximum number of pages to show on single subpage.
*/
protected $maxPerPage = 345;
/**
* Maximum number of pages to show on single index subpage.
*/
protected $maxLineCount = 100;
/**
* Maximum number of chars to show for an entry.
*/
protected $maxPageLength = 70;
/**
* Determines, which message describes the input field 'nsfrom'.
*/
protected $nsfromMsg = 'allpagesfrom';
function __construct( $name = 'Allpages' ){
parent::__construct( $name );
}
/**
* Entry point : initialise variables and call subfunctions.
*
* @param $par String: becomes "FOO" when called like Special:Allpages/FOO (default NULL)
*/
function execute( $par ) {
global $wgRequest, $wgOut, $wgContLang;
$this->setHeaders();
$this->outputHeader();
$wgOut->allowClickjacking();
# GET values
$from = $wgRequest->getVal( 'from', null );
$to = $wgRequest->getVal( 'to', null );
$namespace = $wgRequest->getInt( 'namespace' );
$namespaces = $wgContLang->getNamespaces();
$wgOut->setPagetitle(
( $namespace > 0 && in_array( $namespace, array_keys( $namespaces) ) ) ?
wfMsg( 'allinnamespace', str_replace( '_', ' ', $namespaces[$namespace] ) ) :
wfMsg( 'allarticles' )
);
if( isset($par) ) {
$this->showChunk( $namespace, $par, $to );
} elseif( isset($from) && !isset($to) ) {
$this->showChunk( $namespace, $from, $to );
} else {
$this->showToplevel( $namespace, $from, $to );
}
}
/**
* HTML for the top form
*
* @param $namespace Integer: a namespace constant (default NS_MAIN).
* @param $from String: dbKey we are starting listing at.
* @param $to String: dbKey we are ending listing at.
*/
function namespaceForm( $namespace = NS_MAIN, $from = '', $to = '' ) {
global $wgScript;
$t = $this->getTitle();
$out = Xml::openElement( 'div', array( 'class' => 'namespaceoptions' ) );
$out .= Xml::openElement( 'form', array( 'method' => 'get', 'action' => $wgScript ) );
$out .= Html::hidden( 'title', $t->getPrefixedText() );
$out .= Xml::openElement( 'fieldset' );
$out .= Xml::element( 'legend', null, wfMsg( 'allpages' ) );
$out .= Xml::openElement( 'table', array( 'id' => 'nsselect', 'class' => 'allpages' ) );
$out .= "<tr>
<td class='mw-label'>" .
Xml::label( wfMsg( 'allpagesfrom' ), 'nsfrom' ) .
" </td>
<td class='mw-input'>" .
Xml::input( 'from', 30, str_replace('_',' ',$from), array( 'id' => 'nsfrom' ) ) .
" </td>
</tr>
<tr>
<td class='mw-label'>" .
Xml::label( wfMsg( 'allpagesto' ), 'nsto' ) .
" </td>
<td class='mw-input'>" .
Xml::input( 'to', 30, str_replace('_',' ',$to), array( 'id' => 'nsto' ) ) .
" </td>
</tr>
<tr>
<td class='mw-label'>" .
Xml::label( wfMsg( 'namespace' ), 'namespace' ) .
" </td>
<td class='mw-input'>" .
Xml::namespaceSelector( $namespace, null ) . ' ' .
Xml::submitButton( wfMsg( 'allpagessubmit' ) ) .
" </td>
</tr>";
$out .= Xml::closeElement( 'table' );
$out .= Xml::closeElement( 'fieldset' );
$out .= Xml::closeElement( 'form' );
$out .= Xml::closeElement( 'div' );
return $out;
}
/**
* @param $namespace Integer (default NS_MAIN)
* @param $from String: list all pages from this name
* @param $to String: list all pages to this name
*/
function showToplevel( $namespace = NS_MAIN, $from = '', $to = '' ) {
global $wgOut;
# TODO: Either make this *much* faster or cache the title index points
# in the querycache table.
$dbr = wfGetDB( DB_SLAVE );
$out = "";
$where = array( 'page_namespace' => $namespace );
$from = Title::makeTitleSafe( $namespace, $from );
$to = Title::makeTitleSafe( $namespace, $to );
$from = ( $from && $from->isLocal() ) ? $from->getDBkey() : null;
$to = ( $to && $to->isLocal() ) ? $to->getDBkey() : null;
if( isset($from) )
$where[] = 'page_title >= '.$dbr->addQuotes( $from );
if( isset($to) )
$where[] = 'page_title <= '.$dbr->addQuotes( $to );
global $wgMemc;
$key = wfMemcKey( 'allpages', 'ns', $namespace, $from, $to );
$lines = $wgMemc->get( $key );
$count = $dbr->estimateRowCount( 'page', '*', $where, __METHOD__ );
$maxPerSubpage = intval($count/$this->maxLineCount);
$maxPerSubpage = max($maxPerSubpage,$this->maxPerPage);
if( !is_array( $lines ) ) {
$options = array( 'LIMIT' => 1 );
$options['ORDER BY'] = 'page_title ASC';
$firstTitle = $dbr->selectField( 'page', 'page_title', $where, __METHOD__, $options );
$lastTitle = $firstTitle;
# This array is going to hold the page_titles in order.
$lines = array( $firstTitle );
# If we are going to show n rows, we need n+1 queries to find the relevant titles.
$done = false;
while( !$done ) {
// Fetch the last title of this chunk and the first of the next
$chunk = ( $lastTitle === false )
? array()
: array( 'page_title >= ' . $dbr->addQuotes( $lastTitle ) );
$res = $dbr->select( 'page', /* FROM */
'page_title', /* WHAT */
array_merge($where,$chunk),
__METHOD__,
array ('LIMIT' => 2, 'OFFSET' => $maxPerSubpage - 1, 'ORDER BY' => 'page_title ASC')
);
$s = $dbr->fetchObject( $res );
if( $s ) {
array_push( $lines, $s->page_title );
} else {
// Final chunk, but ended prematurely. Go back and find the end.
$endTitle = $dbr->selectField( 'page', 'MAX(page_title)',
array_merge($where,$chunk),
__METHOD__ );
array_push( $lines, $endTitle );
$done = true;
}
$s = $res->fetchObject();
if( $s ) {
array_push( $lines, $s->page_title );
$lastTitle = $s->page_title;
} else {
// This was a final chunk and ended exactly at the limit.
// Rare but convenient!
$done = true;
}
$res->free();
}
$wgMemc->add( $key, $lines, 3600 );
}
// If there are only two or less sections, don't even display them.
// Instead, display the first section directly.
if( count( $lines ) <= 2 ) {
if( !empty($lines) ) {
$this->showChunk( $namespace, $from, $to );
} else {
$wgOut->addHTML( $this->namespaceForm( $namespace, $from, $to ) );
}
return;
}
# At this point, $lines should contain an even number of elements.
$out .= Xml::openElement( 'table', array( 'class' => 'allpageslist' ) );
while( count ( $lines ) > 0 ) {
$inpoint = array_shift( $lines );
$outpoint = array_shift( $lines );
$out .= $this->showline( $inpoint, $outpoint, $namespace );
}
$out .= Xml::closeElement( 'table' );
$nsForm = $this->namespaceForm( $namespace, $from, $to );
# Is there more?
if( $this->including() ) {
$out2 = '';
} else {
if( isset($from) || isset($to) ) {
global $wgUser;
$out2 = Xml::openElement( 'table', array( 'class' => 'mw-allpages-table-form' ) ).
'<tr>
<td>' .
$nsForm .
'</td>
<td class="mw-allpages-nav">' .
$wgUser->getSkin()->link( $this->getTitle(), wfMsgHtml ( 'allpages' ),
array(), array(), 'known' ) .
"</td>
</tr>" .
Xml::closeElement( 'table' );
} else {
$out2 = $nsForm;
}
}
$wgOut->addHTML( $out2 . $out );
}
/**
* Show a line of "ABC to DEF" ranges of articles
*
* @param $inpoint String: lower limit of pagenames
* @param $outpoint String: upper limit of pagenames
* @param $namespace Integer (Default NS_MAIN)
*/
function showline( $inpoint, $outpoint, $namespace = NS_MAIN ) {
global $wgContLang;
$inpointf = htmlspecialchars( str_replace( '_', ' ', $inpoint ) );
$outpointf = htmlspecialchars( str_replace( '_', ' ', $outpoint ) );
// Don't let the length runaway
$inpointf = $wgContLang->truncate( $inpointf, $this->maxPageLength );
$outpointf = $wgContLang->truncate( $outpointf, $this->maxPageLength );
$queryparams = $namespace ? "namespace=$namespace&" : '';
$special = $this->getTitle();
$link = $special->escapeLocalUrl( $queryparams . 'from=' . urlencode($inpoint) . '&to=' . urlencode($outpoint) );
$out = wfMsgHtml( 'alphaindexline',
"<a href=\"$link\">$inpointf</a></td><td>",
"</td><td><a href=\"$link\">$outpointf</a>"
);
return '<tr><td class="mw-allpages-alphaindexline">' . $out . '</td></tr>';
}
/**
* @param $namespace Integer (Default NS_MAIN)
* @param $from String: list all pages from this name (default FALSE)
* @param $to String: list all pages to this name (default FALSE)
*/
function showChunk( $namespace = NS_MAIN, $from = false, $to = false ) {
global $wgOut, $wgUser, $wgContLang, $wgLang;
$sk = $wgUser->getSkin();
$fromList = $this->getNamespaceKeyAndText($namespace, $from);
$toList = $this->getNamespaceKeyAndText( $namespace, $to );
$namespaces = $wgContLang->getNamespaces();
$n = 0;
if ( !$fromList || !$toList ) {
$out = wfMsgWikiHtml( 'allpagesbadtitle' );
} elseif ( !in_array( $namespace, array_keys( $namespaces ) ) ) {
// Show errormessage and reset to NS_MAIN
$out = wfMsgExt( 'allpages-bad-ns', array( 'parseinline' ), $namespace );
$namespace = NS_MAIN;
} else {
list( $namespace, $fromKey, $from ) = $fromList;
list( , $toKey, $to ) = $toList;
$dbr = wfGetDB( DB_SLAVE );
$conds = array(
'page_namespace' => $namespace,
'page_title >= ' . $dbr->addQuotes( $fromKey )
);
if( $toKey !== "" ) {
$conds[] = 'page_title <= ' . $dbr->addQuotes( $toKey );
}
$res = $dbr->select( 'page',
array( 'page_namespace', 'page_title', 'page_is_redirect' ),
$conds,
__METHOD__,
array(
'ORDER BY' => 'page_title',
'LIMIT' => $this->maxPerPage + 1,
'USE INDEX' => 'name_title',
)
);
if( $res->numRows() > 0 ) {
$out = Xml::openElement( 'table', array( 'class' => 'mw-allpages-table-chunk' ) );
while( ( $n < $this->maxPerPage ) && ( $s = $res->fetchObject() ) ) {
$t = Title::makeTitle( $s->page_namespace, $s->page_title );
if( $t ) {
$link = ( $s->page_is_redirect ? '<div class="allpagesredirect">' : '' ) .
$sk->linkKnown( $t, htmlspecialchars( $t->getText() ) ) .
($s->page_is_redirect ? '</div>' : '' );
} else {
$link = '[[' . htmlspecialchars( $s->page_title ) . ']]';
}
if( $n % 3 == 0 ) {
$out .= '<tr>';
}
$out .= "<td style=\"width:33%\">$link</td>";
$n++;
if( $n % 3 == 0 ) {
$out .= "</tr>\n";
}
}
if( ($n % 3) != 0 ) {
$out .= "</tr>\n";
}
$out .= Xml::closeElement( 'table' );
} else {
$out = '';
}
}
if ( $this->including() ) {
$out2 = '';
} else {
if( $from == '' ) {
// First chunk; no previous link.
$prevTitle = null;
} else {
# Get the last title from previous chunk
$dbr = wfGetDB( DB_SLAVE );
$res_prev = $dbr->select(
'page',
'page_title',
array( 'page_namespace' => $namespace, 'page_title < '.$dbr->addQuotes($from) ),
__METHOD__,
array( 'ORDER BY' => 'page_title DESC',
'LIMIT' => $this->maxPerPage, 'OFFSET' => ($this->maxPerPage - 1 )
)
);
# Get first title of previous complete chunk
if( $dbr->numrows( $res_prev ) >= $this->maxPerPage ) {
$pt = $dbr->fetchObject( $res_prev );
$prevTitle = Title::makeTitle( $namespace, $pt->page_title );
} else {
# The previous chunk is not complete, need to link to the very first title
# available in the database
$options = array( 'LIMIT' => 1 );
if ( ! $dbr->implicitOrderby() ) {
$options['ORDER BY'] = 'page_title';
}
$reallyFirstPage_title = $dbr->selectField( 'page', 'page_title',
array( 'page_namespace' => $namespace ), __METHOD__, $options );
# Show the previous link if it s not the current requested chunk
if( $from != $reallyFirstPage_title ) {
$prevTitle = Title::makeTitle( $namespace, $reallyFirstPage_title );
} else {
$prevTitle = null;
}
}
}
$self = $this->getTitle();
$nsForm = $this->namespaceForm( $namespace, $from, $to );
$out2 = Xml::openElement( 'table', array( 'class' => 'mw-allpages-table-form' ) ).
'<tr>
<td>' .
$nsForm .
'</td>
<td class="mw-allpages-nav">' .
$sk->link( $self, wfMsgHtml ( 'allpages' ), array(), array(), 'known' );
# Do we put a previous link ?
if( isset( $prevTitle ) && $pt = $prevTitle->getText() ) {
$query = array( 'from' => $prevTitle->getText() );
if( $namespace )
$query['namespace'] = $namespace;
$prevLink = $sk->linkKnown(
$self,
htmlspecialchars( wfMsg( 'prevpage', $pt ) ),
array(),
$query
);
$out2 = $wgLang->pipeList( array( $out2, $prevLink ) );
}
if( $n == $this->maxPerPage && $s = $res->fetchObject() ) {
# $s is the first link of the next chunk
$t = Title::MakeTitle($namespace, $s->page_title);
$query = array( 'from' => $t->getText() );
if( $namespace )
$query['namespace'] = $namespace;
$nextLink = $sk->linkKnown(
$self,
htmlspecialchars( wfMsg( 'nextpage', $t->getText() ) ),
array(),
$query
);
$out2 = $wgLang->pipeList( array( $out2, $nextLink ) );
}
$out2 .= "</td></tr></table>";
}
$wgOut->addHTML( $out2 . $out );
if( isset($prevLink) or isset($nextLink) ) {
$wgOut->addHTML( '<hr /><p class="mw-allpages-nav">' );
if( isset( $prevLink ) ) {
$wgOut->addHTML( $prevLink );
}
if( isset( $prevLink ) && isset( $nextLink ) ) {
$wgOut->addHTML( wfMsgExt( 'pipe-separator' , 'escapenoentities' ) );
}
if( isset( $nextLink ) ) {
$wgOut->addHTML( $nextLink );
}
$wgOut->addHTML( '</p>' );
}
}
/**
* @param $ns Integer: the namespace of the article
* @param $text String: the name of the article
* @return array( int namespace, string dbkey, string pagename ) or NULL on error
* @static (sort of)
* @access private
*/
function getNamespaceKeyAndText($ns, $text) {
if ( $text == '' )
return array( $ns, '', '' ); # shortcut for common case
$t = Title::makeTitleSafe($ns, $text);
if ( $t && $t->isLocal() ) {
return array( $t->getNamespace(), $t->getDBkey(), $t->getText() );
} else if ( $t ) {
return null;
}
# try again, in case the problem was an empty pagename
$text = preg_replace('/(#|$)/', 'X$1', $text);
$t = Title::makeTitleSafe($ns, $text);
if ( $t && $t->isLocal() ) {
return array( $t->getNamespace(), '', '' );
} else {
return null;
}
}
}