t3blog - how to clear cache when user writes comment? - typo3

Question

When a user writes a comment then it doesn't become visible right away. It becomes visible if I clear the cache manually.
Usually t3blog stores posts and comments within the t3blog page itself and then one should be able to clear the cache this way.
TCEMAIN.clearCacheCmd = all
However in my t3blog setup the posts and comments are in a separate sysfolder. Here is the setup typoscript
plugin.tx_t3blog_pi1.blogPid = 21
Is there a way I can trigger clear cache when the user submits a new comment?

Answer 1

I have unsuccessfully tried installing an 'aftercommentinsertion' hook.
Finally I solved it by modifying t3blog itself, so that you can specify the uid of the pages that needs to be cleared via typoscript.
# my typoscript code
plugin.tx_t3blog_pi1.blogList {
# clear these pages when a visitor writes a new comment to a post
clearCacheForPIDsAfterCommentInsertion = 1,6,8,24
}
// the file: t3blog/pi1/widgets/blogList/class.singleFunctions.php
protected function insertNewComment(array $data) {
$data['pid'] = t3blog_div::getBlogPid();
$data['date'] = $data['crdate'] = $GLOBALS['EXEC_TIME'];
$GLOBALS['TYPO3_DB']->exec_INSERTquery('tx_t3blog_com', $data);
$commendId = $GLOBALS['TYPO3_DB']->sql_insert_id();
$this->updateRefIndex('tx_t3blog_com', $commentId);
// Hook after comment insertion
if (is_array($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['t3blog']['aftercommentinsertion'])) {
foreach($GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['t3blog']['aftercommentinsertion'] as $userFunc) {
$params = array(
'data' => &$data,
'table' => 'tx_t3blog_com',
'postUid' => $data['fk_post'],
'commentUid' => $commendId,
);
t3lib_div::callUserFunction($userFunc, $params, $this);
}
}
// ******************* MY CLEAR CACHE CODE *******************
error_log("t3blog inserted new comment");
$pids = $this->conf['clearCacheForPIDsAfterCommentInsertion'];
$pidArray = is_string($pids) ? t3lib_div::trimExplode(',', $pids, 1) : NULL;
error_log("t3blog clearCacheForPIDsAfterCommentInsertion: ".$pids." -- ".print_r($pidArray, true));
if(is_array($pidArray)) {
$tce = t3lib_div::makeInstance('t3lib_TCEmain');
foreach($pidArray as $pid) {
error_log("t3blog clear_cacheCmd: ".$pid);
$tce->clear_cacheCmd((int)$pid);
}
}
}
I have sendt this code to Dmitry Dulepov (the author of t3blog).

Answer 2

You can add this line in your PAGE TS of the sysfolder (uid=21) holding your blog post:
TCEMAIN.clearCacheCmd = 1,6,8,24
That line will tell that new blog posts shall trigger a clear cache of that exact list of pages. I think your users will need rights to clear cache though...
Reason it goes into the PAGE TS of you sysfolder and not one or all of the pages where your blog is inserted is that... they are (probably) all cached. Your sysfolder is not cached and the new record will be noticed by TYPO3 and tricker a clear cache of the cached pages you just defined by your comma separated string.

Answer 3

Did you try to include the clearCacheCmd in the page TSconfig of the sysfolder where the comments are stored? You can use "all", "pages" or the relevant page uids, cf: http://typo3.org/documentation/document-library/core-documentation/doc_core_tsconfig/4.3.2/view/1/5/#id2505694
This should work if the "user" is a backend user with the relevant priveleges - but I guess, when you say "a user writes a comment", it is a front end user you are talking about, and then this will probably not be of much help.
The solution then would be to have the extension clear the cache upon receiving a comment. This might not be possible for you to do, but the quick fix to this is to mark the page as not cacheable ("Disable cache", Behavior tab). Beware, though, this will cause your server to suffer.