The cache build process generally follows these steps:
- render the whole document as usual (for example a page) but insert special markers before and after the rendered segments
- parse the rendered document and extract segments by the previously added markers
This results in two artifacts:
- an array of content segments which are later stored as cache entries (if they may be cached)
- a string called "output" which is the originally rendered output but without the markers
We use non-visible ASCII characters as markers / tokens in order to minimize potential conflicts with the actual content.
Note: If you choose a different cache backend for this content cache, make sure that it is one implementing
TaggableBackendInterface.
/**
* Flush caches according to the previously registered node changes.
*
* @return void
*/
public function shutdownObject()
{
if ($this->tagsToFlush !== array()) {
foreach ($this->tagsToFlush as $tag => $logMessage) {
$affectedEntries = $this->contentCache->flushByTag($tag);
if ($affectedEntries > 0) {
$this->systemLogger->log(sprintf('Content cache: Removed %s entries %s', $affectedEntries, $logMessage), LOG_DEBUG);
}
}
}
}
/**
* @test
*/
public function exceptionInAlreadyCachedSegmentShouldNotLeaveSegmentMarkersInOutput()
{
$object = new TestModel(42, 'Object value 1');
$view = $this->buildView();
$view->setOption('enableContentCache', true);
$view->setTypoScriptPath('contentCache/nestedCacheSegmentsWithConditionalException');
$view->assign('object', $object);
$view->assign('throwException', false);
$firstRenderResult = $view->render();
$this->assertEquals('Cached segment|counter=1|It depends|End segment', $firstRenderResult);
$this->contentCache->flushByTag('Inner');
$view->assign('throwException', true);
$secondRenderResult = $view->render();
$this->assertStringStartsWith('Cached segment|counter=1|Exception', $secondRenderResult);
}
/**
* Post process output for caching information
*
* The content cache stores cache segments with markers inside the generated content. This method creates cache
* segments and will process the final outer result (currentPathIsEntryPoint) to remove all cache markers and
* store cache entries.
*
* @param array $evaluateContext The current evaluation context
* @param object $tsObject The current TypoScript object (for "this" in evaluations)
* @param mixed $output The generated output after caching information was removed
* @return mixed The post-processed output with cache segment markers or cleaned for the entry point
*/
public function postProcess(array $evaluateContext, $tsObject, $output)
{
if ($this->enableContentCache && $evaluateContext['cacheForPathEnabled'] && $evaluateContext['cacheForPathDisabled']) {
$contextArray = $this->runtime->getCurrentContext();
if (isset($evaluateContext['configuration']['context'])) {
$contextVariables = [];
foreach ($evaluateContext['configuration']['context'] as $contextVariableName) {
$contextVariables[$contextVariableName] = $contextArray[$contextVariableName];
}
} else {
$contextVariables = $contextArray;
}
$cacheTags = $this->buildCacheTags($evaluateContext['configuration'], $evaluateContext['typoScriptPath'], $tsObject);
$cacheMetadata = array_pop($this->cacheMetadata);
$output = $this->contentCache->createDynamicCachedSegment($output, $evaluateContext['typoScriptPath'], $contextVariables, $evaluateContext['cacheIdentifierValues'], $cacheTags, $cacheMetadata['lifetime'], $evaluateContext['cacheDiscriminator']);
} elseif ($this->enableContentCache && $evaluateContext['cacheForPathEnabled']) {
$cacheTags = $this->buildCacheTags($evaluateContext['configuration'], $evaluateContext['typoScriptPath'], $tsObject);
$cacheMetadata = array_pop($this->cacheMetadata);
$output = $this->contentCache->createCacheSegment($output, $evaluateContext['typoScriptPath'], $evaluateContext['cacheIdentifierValues'], $cacheTags, $cacheMetadata['lifetime']);
} elseif ($this->enableContentCache && $evaluateContext['cacheForPathDisabled'] && $this->inCacheEntryPoint) {
$contextArray = $this->runtime->getCurrentContext();
if (isset($evaluateContext['configuration']['context'])) {
$contextVariables = [];
foreach ($evaluateContext['configuration']['context'] as $contextVariableName) {
if (isset($contextArray[$contextVariableName])) {
$contextVariables[$contextVariableName] = $contextArray[$contextVariableName];
} else {
$contextVariables[$contextVariableName] = null;
}
}
} else {
$contextVariables = $contextArray;
}
$output = $this->contentCache->createUncachedSegment($output, $evaluateContext['typoScriptPath'], $contextVariables);
}
if ($evaluateContext['cacheForPathEnabled'] && $evaluateContext['currentPathIsEntryPoint']) {
$output = $this->contentCache->processCacheSegments($output, $this->enableContentCache);
$this->inCacheEntryPoint = null;
$this->addCacheSegmentMarkersToPlaceholders = false;
}
return $output;
}
