More on Dropdowns

hotwire132002

More on dropdowns-- I have a "update price" button working, which calculates a price based on the dropdown selections. Problem is, once the price is updated, the dropdowns reset to their default values. Is there a way to avoid this, and have the dropdowns keep their values?

psikic

Its pretty easy.

HTML provides a keyword to explicitly set which option in a dropdown is selected when the page is displayed.

<select name="test">
   <option value="1">1</option>
   <option value="2" selected>2</option>
   <option value="3">3</option>
</select>

The code above makes 2 be selected automatically. Just have an if statement that writes out <option value> or <option value selected> based on whether that value is the one that was stored or not.

😃

Psikic

hotwire132002

Originally posted by psikic
Its pretty easy.

HTML provides a keyword to explicitly set which option in a dropdown is selected when the page is displayed.
<select name="test">
   <option value="1">1</option>
   <option value="2" selected>2</option>
   <option value="3">3</option>
</select>
The code above makes 2 be selected automatically. Just have an if statement that writes out <option value> or <option value selected> based on whether that value is the one that was stored or not.

😃

Psikic [/B]

I'm still pretty new to PHP (i.e. learned it yesterday 😉 )... can you show me how to code the if statement?

psikic

I can't show you exactly, but your code will look similar based on what your variables are named, etc... but this is similar to how it should be:

$oldValue = $_POST['oldvalue'] // assuming this is the old value

print '<select name="values">';

for ($i=1; $i<=10; $i++) {
  if ($i == $oldValue) {
    print '<option selected value="$oldValue">$oldValue</option>';
  }
  else {
    print '<option value="$oldValue">$oldValue</option>';
  }
}

print '</select>';

Basically, before you write each option for the dropdown, decide if it is the selected one, and write selected if so.

Psikic

hotwire132002

Originally posted by psikic
I can't show you exactly, but your code will look similar based on what your variables are named, etc... but this is similar to how it should be:
$oldValue = $_POST['oldvalue'] // assuming this is the old value

print '<select name="values">';

for ($i=1; $i<=10; $i++) {
  if ($i == $oldValue) {
    print '<option selected value="$oldValue">$oldValue</option>';
  }
  else {
    print '<option value="$oldValue">$oldValue</option>';
  }
}

print '</select>';
Basically, before you write each option for the dropdown, decide if it is the selected one, and write selected if so.

Psikic [/B]

in the line $oldValue = $_POST['oldvalue'], is oldvalue the name of the submit, the selection box, or what ? 😕 Other than that, I got it.

psikic

$_POST['oldvalue'] retrieves the value from a form where the form method is listed as POST and there is a dropdown box name oldvalue.

$_GET['oldvalue'] retrieves the value from a form with method GET or from the address of the page; example: index.php?oldvalue=2

or... if the value comes from a calculation, you can just use the name of the variable that holds the result.

Actually there was a mistake in my code, it should have been <select name="oldvalue"> and it should have been on a form such as <form method="POST">.

in the line $oldValue = $POST['oldvalue'], is oldvalue the name of the submit, the selection box, or what ? Other than that, I got it.
$oldValue = $_POST['oldvalue'] // assuming this is the old value