[TYPO3-dev] cHash revisited

[Elmar Hinz]

Hello typoniks,

while working on a successor for pi_base I am analysing the caching
mechanisms again. We usually have two cases: We want caching or we do not
want it.

To reach caching we do in piBase:

1.) using USER
2.) $pi_checkCHash = TRUE;
3.) configuring each link to produce a cHash


To inhibt caching we do:

1.) using USER_INT
2.) $pi_USER_INT_obj = TRUE;

To me it seems that there is more to configure then would be necessary to
give the information. But unecssary inforamtions are allways confusing and
lead to mistakes.

Ideally I would like to do one step using USER or USER_INT.


Why isn't that enough information?

Answer:

There are situations, where we link from one object USER_INT (search) to
USER (details). We simply could always produce a cHash if necessary or not.
But that is ugly. So we need to inform the link in each case if we wan't a
cHash or not.

Now we have:

1.) using USER or USER_INT
2.) configuering the links

But what are $pi_checkCHash and $pi_USER_INT_obj good for?

---------------------------------------------------------------------------
A) $pi_checkCHash
---------------------------------------------------------------------------

$pi_checkCHash is only used in line 223  of pi_base:

00223  if ($this->pi_checkCHash && count($this->piVars)) {
00224     $GLOBALS['TSFE']->reqCHash();
00225  }

Why dont we discard $pi_checkCHash and say:

00223  if (count($this->piVars)) {
00224     $GLOBALS['TSFE']->reqCHash();
00225  }

If $GLOBALS['TSFE']->reqCHash(); because of absence of cHash nothing is
lost. Is there any problem without, that I don't see?


---------------------------------------------------------------------------
B) $pi_USER_INT_obj
---------------------------------------------------------------------------

The sourcecode comment says:    // If set, then links are 1) not using
cHash and 2) not allowing pages to be cached. (Set this for all USER_INT
plugins!)

Why do we need this?

2.) USER_INT are never cached by definition. What is the additional function?

1.) As mentioned above, we often link from USER_INT to USER. We want a
cHash in such links, even on the same page. (pi_linkTP)

Anyway pi_base links don't create a cHash by default, only if specially
requested for each link. So why additionally suppressing them?



$pi_USER_INT_obj is only used in this function (line 308):

function pi_linkTP($str,$urlParameters=array(), $cache=0,$altPageId=0)   {
  $conf=array();
//-------------------------------------------------------------------
  $conf['useCacheHash'] = $this->pi_USER_INT_obj ? 0 : $cache;
  $conf['no_cache'] = $this->pi_USER_INT_obj ? 0 : !$cache;
//-------------------------------------------------------------------
  $conf['parameter'] = $altPageId ? $altPageId : ($this->pi_tmpPageId ?
                       $this->pi_tmpPageId : $GLOBALS['TSFE']->id);
  $conf['additionalParams'] = $this->conf['parent.']['addParams']
.t3lib_div::implodeArrayForUrl('',$urlParameters,'',1).$this->pi_moreParams;
  return $this->cObj->typoLink($str, $conf);
}


Why not plain:

function pi_linkTP($str, $urlParameters=array(), $cache=0, $altPageId=0)   {
  $conf=array();
//-------------------------------------------------------------------
  $conf['useCacheHash'] =  $cache;
  // Without cHash it's not cached anyway.
//-------------------------------------------------------------------
  $conf['parameter'] = $altPageId ? $altPageId : ($this->pi_tmpPageId ?
                       $this->pi_tmpPageId : $GLOBALS['TSFE']->id);
  $conf['additionalParams'] = $this->conf['parent.']['addParams']
.t3lib_div::implodeArrayForUrl('',$urlParameters,'',1).$this->pi_moreParams;
  return $this->cObj->typoLink($str, $conf);
}



Regards

Elmar