[Resolved] Form keeps resubmitting

[stringman]

Hello all. I have created a slide show which presents charts to the user. The user selects a product from a drop-down box, which has the value of the directory in which the chart is located. Then I build the directory path based on the product selected. This works the 1st time a product is selected, however, once the user selects the "back" or "next" button to navigate to the next chart in the directory, the page refreshes and the drop-down box text returns to the default text of "Select a Product", which has no value (""). The "onchange" event of the drop-down box submits the form on refresh/reload. The correct chart displays and the numbering is correct (i.e., current and total pics), but the user doesn't know what product he is viewing because the drop-down box says "Select a Product" instead of the product selected.

I can't use a static variable to hold the value of the last directory (i.e., product) selected because when the page is refreshed, all the drop-down boxes are refreshed. I also looked into using a semaphore to access the variable from shared memory, but this won't work with Windows. The "back" or "next" buttons are just a links containing the complete path of the chart.

Any help would be greatly appreciated. Thanks in advance.

Ken

[bretticus]

I suggest storing the chart or drop-down values in session variables. This is the easiest way to perform serialization across dynamic pages and/or controls (drop-downs, etc.) It has it's caveats nonetheless. For instance, when a session times out, the boxes revert to default values once more. In this case you simply check for the existance of a session and if not found, redirect to the default page (or alternately, you could use cookies or a cludgy hidden fields generator.)

if (!session_is_registered("MyTestVar")){
   if (!headers_sent())
         header("Location: /page.htm");
}

As for the drop-down menus, you could either populate them from a database, an array, or even read the files from directory (depending on how your system works.) Then when you are writing out the options to the browser, check for the session variable being equal to the current value...

echo "<select name=\"mnuName\">\n";
foreach ($dropdowns as $value => $label) {
   echo "<option value=\"$value\"";
   echo ($_SESSION['thisVar'] == $value) ? " selected" : "";
  echo ">$label\n";
}
echo "</select>\n";

All code is untested, use at own risk. Either way, this should point you in the right direction.

[stringman]

Thanks. I have not yet used session variables, but I guess its time to learn. I'll give it a try.

Ken

[stringman]

I love session variables! Problem solved in about 15 minutes. Thanks bretticus.