undefined function.. that suddenly exists!

ppowell

/**
 * Class for performing the search
 *
 * @author Phil Powell
 * @version 1.0.0
 * @package IMAGE_CATALOG
 * @see db_action.inc.php:DBActionPerformer
 */
class SearchPerformer extends DBActionPerformer {


/**
  * This static method will determine if the element passed here (by the value of $elementName as parameter) has a value, even if it is an array
  * 
  * @access private
  * @param mixed $elementName
  * @param mixed $section
  * @return boolean
  */
function &isElement($elementName, $section) {			// STATIC BOOLEAN METHOD
	global ${$elementName};		// PASS VALUE HERE
	switch ($section) {

	 case 'image':				// SPECIFIC IMAGE-RELATED HANDLING OF $this->formFieldsArray
	  /*---------------------------------------------------------------------------------------------------------------------------------------------------------------
		Also note that you have to call Accepter "statically" (class-level) instead of instantiating the object, otherwise,
		you will be instantiating $this->validate(), causing a n^2 loop construct of an unnecessary validation call, which is
		way bad!  However, the property cannot be called directly in PHP versions 4 due to language constraints (if someone knows how
		let *ME* know!) so you have to use a static getter method to retrieve it
	  -----------------------------------------------------------------------------------------------------------------------------------------------------------------*/
	  print_r(is_array(${$elementName})); print_r(" "); print_r(@sizeof(array_values(${$elementName}))); print_r(' '); print_r(${$elementName}); print_r(" "); echo Accepter::getNullExemptionArray($section, $elementName); print_r("<P>");
	  if (is_array(${$elementName}) && @sizeof(array_values(${$elementName})) > 0) {
	   return true;
	  } elseif (${$elementName} && ${$elementName} !== Accepter::getNullExemptionArray($section, $elementName)) {
	   return true;
	  } else {
	   return false;
	  }
	  break;

 	 default: // DO NOTHING FOR NOW
	  break;
	}
}

}

The following method in the class function:

print_r(is_array(${$elementName})); print_r(" "); print_r(@sizeof(array_values(${$elementName}))); print_r(' '); print_r(${$elementName}); print_r(" "); echo Accepter::getNullExemptionArray($section, $elementName); print_r("<P>");

Produces this error:

Fatal error: Call to undefined function: getnullexemptionarray() in /include/search_action.inc.php on line 267

However, if I comment out line 267 and you follow THIS line:

	  } elseif (${$elementName} && ${$elementName} !== Accepter::getNullExemptionArray($section, $elementName)) {
		   return true;

Then the class method works w/o a single fatal error whatsoever, and I even verified with the following:

print_r("elementName = $elementName = ${$elementName}<P>");

To verify if ${$elementName} exists thus possibly meeting (or not meeting) the conditon.

So now, why is it that on one line, Accepter::getNullExemptionArray() produces an "undefined function" fatal error, but in another line, same class, same method, it produces no errors at all???

What am I missing this time?

Phil

ppowell

Perhaps it'll be easier to understand if you look at it knowing Java:

public class Accepter extends SearchHandler {

static final String[] nullExemptionArray = {'blah' => 'whatever'};

static final String getNullExemptionArray(String section, String elementName) {
if (nullExemptionArray[section][elementName].equals("") or nullExemptionArray[section][elementName] == null) return "";
return nullExemptionArray[section][elementName];
}

}

....

out.println(Accepter.getNullExemptionArray(section, elementName));

That might help explain my problem a little better if you look at it from the Java end.

In other words, I don't want to instantiate an Accepter object, I must call it class-level only.

Phil

ppowell

I got it, but it's a terrible solution that, I'm sorry, exposes a gaping hole in PHP OO design that makes Java win over in this case..

class Accepter extends SearchHandler {

 var $nullExemptionArray = array('image' => array('image_location_country' => 'us'));

 var $validationFieldsExemptionArray = array('image' => array('allAlbums', 'album[]'));


/**
  * Constructor will perform validate() method only to ensure script structural simplicity
  *
  * @access public
  */
function Accepter() {							// CONSTRUCTOR
	$this->validate();
}


/**
 * Retrieve $this->nullExemptionArray[$section][$elementName] (useful mainly for classes that call Accepter statically)
 *
 * @access public
 * @param mixed $section
 * @param mixed $elementName
 * @return mixed $this->nullExemptionArray[$section][$elementName]
 */
function &getNullExemptionArrayValue($section, $elementName) {				// STATIC STRING METHOD
	if (!isset($this->nullExemptionArray)) $this->nullExemptionArray = array('image' => array('image_location_country' => 'us'));
	return $this->nullExemptionArray[$section][$elementName];
}

/**
 * Retrieve $this->validationFieldsExemptionArray (useful mainly for classes that call Accepter statically). Note that if 
 * $this->validationFieldsExemptionArray[$section] does not exist or is empty, return an empty array instead
 *
 * @access public
 * @param mixed $section
 * @return array $this->validationFieldsExemptionArray[$section] array
 */
function &getValidationFieldsExemptionArray($section) {				// STATIC ARRAY METHOD
	if (!isset($this->validationFieldsExemptionArray)) 
	 $this->validationFieldsExemptionArray = array('image' => array('allAlbums', 'album[]'));
	if (is_array($this->validationFieldsExemptionArray[$section]) && @sizeof($this->validationFieldsExemptionArray[$section]) > 0) 
	 return $this->validationFieldsExemptionArray[$section]; 
	return array();
}


}

If you instantiate an Accepter object:

 $accepter =& new Accepter();

Then you're set, the properties exist. However, other classes need to borrow those public properties and will not be able to do so because they will not exist if Accepter is called statically, which is has to be called otherwise you unnecessarily call $this->validate() every time.

e.g.:

if (Accepter::getNullExemptionArrayValue($section, $elementName)) { // DO STUFF }

So the only way around this PHP problem is to literally recreate the properties in the 2 methods I wrote above if isset() is false for each of them, then they exist again.

So in other words, to circumvent a problem in PHP to call properties statically from a static class-level call, you have to reset properties.. twice.

Wow.

Phil

Weedpacket

Um, your original code works for me (as far as I can tell; there isn't exactly a working test harness available).

ppowell

It worked and didn't work.. it worked after I changed "getNullExemptionArray" to "getNullExemptionArrayValue" (oops), but then I still had to re-declare the class properties inside the methods whenever I would not instantiate an Accepter object.

I am using PHP 4.3.2 what are you using?

Phil

Weedpacket

Yeah, I was going to drop that post when I realised I was using PHP5....