[RESOLVED] populating drop down lists

shadiadi

Sorry probably an easy question what can i use or rather how can i make the second drop down box repopulate with the correct data once the first selection has been made?
How do I get the page to reload after the first drop down item has been selected?

<table class="postad">
<form name="postad" method="post" action='submidad.php'>
<tr><td><h1>EDIT AD Ref <?=$id?></h1></td></tr>
<tr><td>
<table class="postadmain">
<tr><td>&nbsp</td></tr>
<tr><td><span id="t_cat">CATEGORY</span></td></tr>
<tr><td>
<?
$sql01 = "select * from tblcatdetails";
$run_query = mysql_query($sql01);
echo '<select name="category"><option name="category">Select One</option>';
while($row = mysql_fetch_array($run_query)) {
echo '<option value="'.$row['intCatID'].'">'.$row['category'].'</option>';
}
?>
</td></tr>
<tr><td>
<?
$sql02 = "select * from tblsubcatdetails where intSubCatID='intCatID'";
$run_query = mysql_query($sql02);
echo '<select name="subcategory"><option name="subcategory">Select One</option>';
while($row = mysql_fetch_array($run_query)) {
echo '<option value="'.$row['intSubCatID'].'">'.$row['subcategory'].'</option>';
}
?>
</td></tr>
<form>
</table>

walterquez

There are many ways to do this. One is not to reload and use JavaScript to change the values of the second select. This would require a previously declared 2D array with the second key of the array holding values for the first key. Then you rewrite the content of the select box.

If you must reload, then you still need JavaScript to at least auto-submit the form back to itself. But you must pass some other value letting it know it is not really submitting a form, but changing the content of a select. And there are many ways to do this.

shadiadi

mmm i just solved it with javascript thanks

NogDog

shadiadi;10897232 wrote:
mmm i just solved it with javascript thanks

Did you include some way for the form to work if the user does not have JavaScript enabled, or are you willing to not support those users? (It's a small percentage of users, but a non-zero number.)

walterquez

Sorry, I guess I did not really answer the question. For the sake of others reading this, you can add this JavaScript in the select box.

<select name="category" onchange="this.form.submit();">

Or better yet, instead of auto submitting the form, call a function instead that does some checking and then auto submits the form.

shadiadi

i used this

<SCRIPT language=JavaScript>
<!--
function reload(form)
{

var val=form.cat.options[form.cat.options.selectedIndex].value;
self.location='updatead.php?$adid=$id&cat=' + val ;

}
function disableselect()
{
<?
if(isset($cat) and strlen($cat) > 0){
echo "document.postad.subcat.disabled = false;";}
else{echo "document.postad.subcat.disabled = true;";}
?>
}
//-->

echo "<select name='cat' onchange=\"reload(this.form)\"><option value=''>$category</option>";

How would you do this without javascript? Obviously if there is a way it would be better to use that?

NogDog

Without Javascript you would have to make it a multi-page sequence, making the first selection on the first page, submitting that form, then displaying the rest of the form on the second page with the second select options based on the first selection.

You can actually do both by using JavaScript to write the HTML for the JavaScript solution, then using content within <noscript>...</noscript> tags to output the HTML code for the non-JavaScript solution. This would be the most user-friendly method, but of course requires more coding and more testing on your part.