NYCPHP Meetup

[Phillip Powell]

Very first lines of index.php:

[PHP]
session_start();        // USED FOR ANY STORED SESSION VARIABLES (ONLY 
HAS TO BE SET HERE)
echo "PHPSESSID = $PHPSESSID<P>";
echo "SESSION the moment you first enter this script of $PHP_SELF is: "; 
print_r(array_keys($_SESSION)); echo'<P>';
[/PHP]

This is what you see the moment you first go into index.php and have not 
yet submitted a search query:

[QUOTE]
PHPSESSID = a964d0d6683757cafbe5576737ea5bf9

SESSION the moment you first enter this script of 
/image_catalog/index.php is: Array ( [0] => search [1] => sql )
[/QUOTE]

Ok, now you submitted a search query.  You entered some form stuff and 
submitted.  You're now at the search results page (which is also 
"index.php"); this is what you see:

[QUOTE]
PHPSESSID = a964d0d6683757cafbe5576737ea5bf9

SESSION the moment you first enter this script of 
/image_catalog/index.php is: Array ( [0] => search [1] => sql )

GET: Array ( )

POST: Array ( [0] => image_name [1] => allAlbums [2] => album [3] => 
boolword [4] => keywords [5] => persons [6] => events [7] => image_alt 
[8] => image_creation_start_month [9] => image_creation_start_day [10] 
=> image_creation_start_year [11] => image_creation_end_month [12] => 
image_creation_end_day [13] => image_creation_end_year [14] => 
image_location_city [15] => image_location_state [16] => 
image_location_country [17] => sortBy [18] => search [19] => 
isFromSearch [20] => section )

SESSION: Array ( [0] => search [1] => sql )

PHPSESSID = a964d0d6683757cafbe5576737ea5bf9

SESSION after setting it is: Array ( [0] => search [1] => sql [2] => 
hidden )
[/QUOTE]

(note: to save space and sensitive info I am not doing: 
[PHP]print_r($_POST);[/PHP] but instead I'm using 
[PHP]print_r(array_keys($_POST));[/PHP], and the same with $_GET)

$_SESSION['sql'] is set via an instance of SearchPerformer object that 
runs the generateSearchSQL() method:

[PHP]
class SearchPerformer extends DBActionPerformer {

 function SearchPerformer () {  // CONSTRUCTOR
  $this->doSearch();            // THIS METHOD RUNS generateSearchSQL()
 }

 function &displayResults() {     // STATIC HTML STRING METHOD
  $html  = SearchView::retainFormElements($html);    // SEE BELOW FOR 
CODE DETAIL
  // DO MORE STUFF TO $html
  return $html;
 }

 function generateSearchSQL() {    // SQL STRING METHOD
  // BUILD $sql HERE WITH STUFF
  $_SESSION['sql'] = $sql;
  // DO MORE STUFF
  return $sql;
 }

}

$performer =& new SearchPerformer(); // CONSTRUCTOR
[/PHP]

So everything is fine so far; I have $_SESSION['sql'] and I even have 
$_SESSION['hidden'] which is set via the displayResults() method in the 
SearchPerformer object, it running this class method (class SearchView 
is *NOT* instantiated here!!!):

[PHP]
class SearchView extends View {

     function SearchView() {}    // CONSTRUCTOR (you will be 
instantiating SearchView objects elsewhere, just not in 
SearchPerformer's methods)

     function &retainFormElements(&$html) {                // STATIC 
HTML METHOD
                print_r("<P>GET: "); print_r(array_keys($_GET)); 
print_r("<P>POST: "); print_r(array_keys($_POST));
print_r("<P>SESSION: "); print_r(array_keys($_SESSION)); print_r("<P>");
        if ((!is_array($_POST) || @sizeof(array_values($_POST)) == 0) &&
$_SESSION['hidden']) {
         $html .= $_SESSION['hidden'];
        } else {
        
 /*--------------------------------------------------------------------------------------------------------------------
            Set $collection to either $_POST (if form post variables 
exist in $_POST) or default to $_GET
            to parse through either/or and produce HTML hidden elements 
in either case
        
 ---------------------------------------------------------------------------------------------------------------------*/
         $collection = ($_POST && is_array($_POST) && 
@sizeof(array_values($_POST)) > 0) ? $_POST : $_GET;
         foreach ($collection as $key => $val) {
          if (!is_array($val)) {
           $hiddenHTMLRetainer .= "<input type=\"hidden\" name=\"$key\" 
value=\"$val\">\n";
           $html .= "<input type=\"hidden\" name=\"$key\" 
value=\"$val\">\n";    // ADD FROM QS TO PASS BACK
          } else {
           foreach ($val as $innerKey => $indivVal) {
            if ($indivVal) {
             $hiddenHTMLRetainer .= "<input type=\"hidden\" name=\"${key}[";
             $html .= "<input type=\"hidden\" name=\"${key}[";
             if (!is_numeric($innerKey)) $html .= $innerKey;    // 
NUMERICAL KEYS DO NOT NEED TO BE PLACED INTO HTML ARRAY-FORMATTABLE FORM 
ELEMENTS
             if (!is_numeric($innerKey)) $hiddenHTMLRetainer .= $innerKey;
             $html .= "]\" value=\"$indivVal\">\n";    // PUT IN 
INDIVIDUAL ARRAY ELEMENTS
             $hiddenHTMLRetainer .= "]\" value=\"$indivVal\">\n";
            }
           }
          }
         }
         $_SESSION['hidden'] = $hiddenHTMLRetainer;
         global $PHPSESSID;
         print_r("PHPSESSID = "); print_r($PHPSESSID); print_r("<P>");
         print_r('SESSION after setting it is: '); 
print_r(array_keys($_SESSION));
        }
        return $html;
    }

}
[/PHP]
Now, in the search results page I click a link to sort my results.  The 
link takes me back to, you guessed it, index.php (in fact, every single 
portion of my application literally has only one address: "index.php" 
and nowhere else).  The moment I do that, this is what I see:

[QUOTE]
PHPSESSID = a964d0d6683757cafbe5576737ea5bf9

SESSION the moment you first enter this script of 
/mu-spin/image_catalog/index.php is: Array ( [0] => search [1] => sql )

GET: Array ( [0] => section [1] => search [2] => isSort [3] => sortBy )

POST: Array ( )

SESSION: Array ( [0] => search [1] => sql )

PHPSESSID = a964d0d6683757cafbe5576737ea5bf9

SESSION after setting it is: Array ( [0] => search [1] => sql [2] => 
hidden )
[/QUOTE]

This is totally wrong!!! The $_SESSION['hidden'] variable is gone!!! It 
is, in fact, erroneously RESET once again (with the wrong values), 
whereas it was supposed to have been retained within $_SESSION 
superglobal array, yet it is not.

I hope this makes it a bit more clear as to what is literally going on.

Synopsis:

1) I go to index.php
2) I see $_SESSION
3) I submit form elements
4) I see $_SESSION
5) I add $_SESSION['sql'] in generateSearchSQL() method
6) I add $_SESSION['hidden'] in SearchView::retainFormElements() method
7) I see $_SESSION with both elements
8) I click a link to go back to index.php
9) I see $_SESSION.. with just 'sql' and NOT 'hidden'
10) I tear my hair out, what little I have left!

Phil

-- 
---------------------------------------------------------------------------------
Phil Powell
Multimedia Programmer
ADNET Systems., Inc.
11260 Roger Bacon Drive Suite 403
Reston, VA  20191
#: (703) 709-7218 x107 
Fax: (703) 709-7219