Current File : //proc/thread-self/root/www/varak.net/wiki.varak.net/includes/Revision/RenderedRevision.php
<?php
/**
* This file is part of MediaWiki.
*
* 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
*/
namespace MediaWiki\Revision;
use InvalidArgumentException;
use LogicException;
use ParserOptions;
use ParserOutput;
use Psr\Log\LoggerInterface;
use Psr\Log\NullLogger;
use Revision;
use Title;
use User;
use Content;
use Wikimedia\Assert\Assert;
/**
* RenderedRevision represents the rendered representation of a revision. It acts as a lazy provider
* of ParserOutput objects for the revision's individual slots, as well as a combined ParserOutput
* of all slots.
*
* @since 1.32
*/
class RenderedRevision implements SlotRenderingProvider {
/**
* @var Title
*/
private $title;
/** @var RevisionRecord */
private $revision;
/**
* @var ParserOptions
*/
private $options;
/**
* @var int Audience to check when accessing content.
*/
private $audience = RevisionRecord::FOR_PUBLIC;
/**
* @var User|null The user to use for audience checks during content access.
*/
private $forUser = null;
/**
* @var ParserOutput|null The combined ParserOutput for the revision,
* initialized lazily by getRevisionParserOutput().
*/
private $revisionOutput = null;
/**
* @var ParserOutput[] The ParserOutput for each slot,
* initialized lazily by getSlotParserOutput().
*/
private $slotsOutput = [];
/**
* @var callable Callback for combining slot output into revision output.
* Signature: function ( RenderedRevision $this ): ParserOutput.
*/
private $combineOutput;
/**
* @var LoggerInterface For profiling ParserOutput re-use.
*/
private $saveParseLogger;
/**
* @note Application logic should not instantiate RenderedRevision instances directly,
* but should use a RevisionRenderer instead.
*
* @param Title $title
* @param RevisionRecord $revision The revision to render. The content for rendering will be
* taken from this RevisionRecord. However, if the RevisionRecord is not complete
* according isReadyForInsertion(), but a revision ID is known, the parser may load
* the revision from the database if it needs revision meta data to handle magic
* words like {{REVISIONUSER}}.
* @param ParserOptions $options
* @param callable $combineOutput Callback for combining slot output into revision output.
* Signature: function ( RenderedRevision $this ): ParserOutput.
* @param int $audience Use RevisionRecord::FOR_PUBLIC, FOR_THIS_USER, or RAW.
* @param User|null $forUser Required if $audience is FOR_THIS_USER.
*/
public function __construct(
Title $title,
RevisionRecord $revision,
ParserOptions $options,
callable $combineOutput,
$audience = RevisionRecord::FOR_PUBLIC,
User $forUser = null
) {
$this->title = $title;
$this->options = $options;
$this->setRevisionInternal( $revision );
$this->combineOutput = $combineOutput;
$this->saveParseLogger = new NullLogger();
if ( $audience === RevisionRecord::FOR_THIS_USER && !$forUser ) {
throw new InvalidArgumentException(
'User must be specified when setting audience to FOR_THIS_USER'
);
}
$this->audience = $audience;
$this->forUser = $forUser;
}
/**
* @param LoggerInterface $saveParseLogger
*/
public function setSaveParseLogger( LoggerInterface $saveParseLogger ) {
$this->saveParseLogger = $saveParseLogger;
}
/**
* @return bool Whether the revision's content has been hidden from unprivileged users.
*/
public function isContentDeleted() {
return $this->revision->isDeleted( RevisionRecord::DELETED_TEXT );
}
/**
* @return RevisionRecord
*/
public function getRevision() {
return $this->revision;
}
/**
* @return ParserOptions
*/
public function getOptions() {
return $this->options;
}
/**
* @param array $hints Hints given as an associative array. Known keys:
* - 'generate-html' => bool: Whether the caller is interested in output HTML (as opposed
* to just meta-data). Default is to generate HTML.
*
* @return ParserOutput
*/
public function getRevisionParserOutput( array $hints = [] ) {
$withHtml = $hints['generate-html'] ?? true;
if ( !$this->revisionOutput
|| ( $withHtml && !$this->revisionOutput->hasText() )
) {
$output = call_user_func( $this->combineOutput, $this, $hints );
Assert::postcondition(
$output instanceof ParserOutput,
'Callback did not return a ParserOutput object!'
);
$this->revisionOutput = $output;
}
return $this->revisionOutput;
}
/**
* @param string $role
* @param array $hints Hints given as an associative array. Known keys:
* - 'generate-html' => bool: Whether the caller is interested in output HTML (as opposed
* to just meta-data). Default is to generate HTML.
*
* @throws SuppressedDataException if the content is not accessible for the audience
* specified in the constructor.
* @return ParserOutput
*/
public function getSlotParserOutput( $role, array $hints = [] ) {
$withHtml = $hints['generate-html'] ?? true;
if ( !isset( $this->slotsOutput[ $role ] )
|| ( $withHtml && !$this->slotsOutput[ $role ]->hasText() )
) {
$content = $this->revision->getContent( $role, $this->audience, $this->forUser );
if ( !$content ) {
throw new SuppressedDataException(
'Access to the content has been suppressed for this audience'
);
} else {
$output = $this->getSlotParserOutputUncached( $content, $withHtml );
if ( $withHtml && !$output->hasText() ) {
throw new LogicException(
'HTML generation was requested, but '
. get_class( $content )
. '::getParserOutput() returns a ParserOutput with no text set.'
);
}
// Detach watcher, to ensure option use is not recorded in the wrong ParserOutput.
$this->options->registerWatcher( null );
}
$this->slotsOutput[ $role ] = $output;
}
return $this->slotsOutput[$role];
}
/**
* @note This method exist to make duplicate parses easier to see during profiling
* @param Content $content
* @param bool $withHtml
* @return ParserOutput
*/
private function getSlotParserOutputUncached( Content $content, $withHtml ) {
return $content->getParserOutput(
$this->title,
$this->revision->getId(),
$this->options,
$withHtml
);
}
/**
* Updates the RevisionRecord after the revision has been saved. This can be used to discard
* and cached ParserOutput so parser functions like {{REVISIONTIMESTAMP}} or {{REVISIONID}}
* are re-evaluated.
*
* @note There should be no need to call this for null-edits.
*
* @param RevisionRecord $rev
*/
public function updateRevision( RevisionRecord $rev ) {
if ( $rev->getId() === $this->revision->getId() ) {
return;
}
if ( $this->revision->getId() ) {
throw new LogicException( 'RenderedRevision already has a revision with ID '
. $this->revision->getId(), ', can\'t update to revision with ID ' . $rev->getId() );
}
if ( !$this->revision->getSlots()->hasSameContent( $rev->getSlots() ) ) {
throw new LogicException( 'Cannot update to a revision with different content!' );
}
$this->setRevisionInternal( $rev );
$this->pruneRevisionSensitiveOutput( $this->revision->getId() );
}
/**
* Prune any output that depends on the revision ID.
*
* @param int|bool $actualRevId The actual rev id, to check the used speculative rev ID
* against, or false to not purge on vary-revision-id, or true to purge on
* vary-revision-id unconditionally.
*/
private function pruneRevisionSensitiveOutput( $actualRevId ) {
if ( $this->revisionOutput ) {
if ( $this->outputVariesOnRevisionMetaData( $this->revisionOutput, $actualRevId ) ) {
$this->revisionOutput = null;
}
} else {
$this->saveParseLogger->debug( __METHOD__ . ": no prepared revision output...\n" );
}
foreach ( $this->slotsOutput as $role => $output ) {
if ( $this->outputVariesOnRevisionMetaData( $output, $actualRevId ) ) {
unset( $this->slotsOutput[$role] );
}
}
}
/**
* @param RevisionRecord $revision
*/
private function setRevisionInternal( RevisionRecord $revision ) {
$this->revision = $revision;
// Force the parser to use $this->revision to resolve magic words like {{REVISIONUSER}}
// if the revision is either known to be complete, or it doesn't have a revision ID set.
// If it's incomplete and we have a revision ID, the parser can do better by loading
// the revision from the database if needed to handle a magic word.
//
// The following considerations inform the logic described above:
//
// 1) If we have a saved revision already loaded, we want the parser to use it, instead of
// loading it again.
//
// 2) If the revision is a fake that wraps some kind of synthetic content, such as an
// error message from Article, it should be used directly and things like {{REVISIONUSER}}
// should not expected to work, since there may not even be an actual revision to
// refer to.
//
// 3) If the revision is a fake constructed around a Title, a Content object, and
// a revision ID, to provide backwards compatibility to code that has access to those
// but not to a complete RevisionRecord for rendering, then we want the Parser to
// load the actual revision from the database when it encounters a magic word like
// {{REVISIONUSER}}, but we don't want to load that revision ahead of time just in case.
//
// 4) Previewing an edit to a template should use the submitted unsaved
// MutableRevisionRecord for self-transclusions in the template's documentation (see T7278).
// That revision would be complete except for the ID field.
//
// 5) Pre-save transform would provide a RevisionRecord that has all meta-data but is
// incomplete due to not yet having content set. However, since it doesn't have a revision
// ID either, the below code would still force it to be used, allowing
// {{subst::REVISIONUSER}} to function as expected.
if ( $this->revision->isReadyForInsertion() || !$this->revision->getId() ) {
$title = $this->title;
$oldCallback = $this->options->getCurrentRevisionCallback();
$this->options->setCurrentRevisionCallback(
function ( Title $parserTitle, $parser = false ) use ( $title, $oldCallback ) {
if ( $title->equals( $parserTitle ) ) {
$legacyRevision = new Revision( $this->revision );
return $legacyRevision;
} else {
return call_user_func( $oldCallback, $parserTitle, $parser );
}
}
);
}
}
/**
* @param ParserOutput $out
* @param int|bool $actualRevId The actual rev id, to check the used speculative rev ID
* against, or false to not purge on vary-revision-id, or true to purge on
* vary-revision-id unconditionally.
* @return bool
*/
private function outputVariesOnRevisionMetaData( ParserOutput $out, $actualRevId ) {
$method = __METHOD__;
if ( $out->getFlag( 'vary-revision' ) ) {
// XXX: Would be just keep the output if the speculative revision ID was correct,
// but that can go wrong for some edge cases, like {{PAGEID}} during page creation.
// For that specific case, it would perhaps nice to have a vary-page flag.
$this->saveParseLogger->info(
"$method: Prepared output has vary-revision...\n"
);
return true;
} elseif ( $out->getFlag( 'vary-revision-id' )
&& $actualRevId !== false
&& ( $actualRevId === true || $out->getSpeculativeRevIdUsed() !== $actualRevId )
) {
$this->saveParseLogger->info(
"$method: Prepared output has vary-revision-id with wrong ID...\n"
);
return true;
} else {
// NOTE: In the original fix for T135261, the output was discarded if 'vary-user' was
// set for a null-edit. The reason was that the original rendering in that case was
// targeting the user making the null-edit, not the user who made the original edit,
// causing {{REVISIONUSER}} to return the wrong name.
// This case is now expected to be handled by the code in RevisionRenderer that
// constructs the ParserOptions: For a null-edit, setCurrentRevisionCallback is called
// with the old, existing revision.
wfDebug( "$method: Keeping prepared output...\n" );
return false;
}
}
}
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