Having the child feed the parent - help with Dynamic Dropdowns

We have a list of regions in one recordset and a list of countries in another.

Regions
regionID
regionname
countryID

Countries
countryID
countryname

We want users to be able to select a region and have it auto-complete the country menu, below it, depending on their selection.

Is this possible with WebAssist Dynamic Dropdowns? I've tried following the tutorial but I just can't get the country menu to change once the user has selected the region.

Oh, and I assume this doesn't yet work with MySQLi recordsets?

Thank you.
NJ

Would you still want them to be able to change the Country dropdown? Why show a list if it is already selected with the correct value?

Why not just show the country associated to that region in plain text in a div next to it? I don't think you need dynamic dropdowns in this case, since you are only going to have one option available for each selection.

I think you can probably add the country name to the original region list into another attribute like:

<option value="<?php echo($rs->getColumnVal['RegionID']); ?>" rel="<?php echo($rs->getColumnVal['Country']); ?>">"<?php echo($rs->getColumnVal['RegionName']); ?>"</option>

If you want them to be able to change the country and just have it pre-selected, then use the CountryID column in the rel attribute, if you only want it displayed and not changed, then I'd do an inner join in your Region recordset and put the country name in the rel attribute so you can populate the innerhtml of a span tag next to it.

Then you can add a simple javascript onchange of the region select list that will take the selected option and retrieve the associated rel attribute and use it to either display the country name or set the selection in the other list.

Originally Said By: Ray Borduin

  Would you still want them to be able to change the Country dropdown? Why show a list if it is already selected with the correct value?  

D'oh!

I need the country name displayed, just for reassurance for the client, but it doesn't need a list/menu as you have so correctly highlighted. Thing is, I need to save the country ID to database as well as the region ID.

Originally Said By: Ray Borduin

  I think you can probably add the country name to the original region list into another attribute like:

<option value="<?php echo($rs->getColumnVal['RegionID']); ?>" rel="<?php echo($rs->getColumnVal['Country']); ?>">"<?php echo($rs->getColumnVal['RegionName']); ?>"</option>

If you want them to be able to change the country and just have it pre-selected, then use the CountryID column in the rel attribute, if you only want it displayed and not changed, then I'd do an inner join in your Region recordset and put the country name in the rel attribute so you can populate the innerhtml of a span tag next to it.

Then you can add a simple javascript onchange of the region select list that will take the selected option and retrieve the associated rel attribute and use it to either display the country name or set the selection in the other list.  

I think the best option is not to allow them to change the country. They've selected the region, which is more than sufficient info to populate the country information, and with any luck the countryID into a hidden field, thus saving them a bit of time.

Sorry, I'm not familiar with the rel attribute and searching Google I can only find information about using rel with an a href tag.

This is my regions drop down, which is taken from my regions recordset within which I've done an inner join so that I can drag the country name across in one recordset.

<select id="regionID" name="regionID" class="form-control">
<?php
while(!$rsREGIONS->atEnd()) {
?>
<option value="<?php echo($rsREGIONS->getColumnVal("regionID")); ?>" rel="<?php echo($rsREGIONS->getColumnVal['country']); ?>"><?php echo($rsREGIONS->getColumnVal("region")); ?></option>
<?php
  $rsREGIONS->moveNext();
}
$rsREGIONS->moveFirst(); //return RS to first record
?>
</select>

Below this, I have set up a readonly input field because I'd still like the country to be shown in a form format/layout. I have included a hidden field for the countryID though.

<input type="text" class="form-control" id="country" name="country" placeholder="Country..." readonly>
<input type="hidden" id="countryID" name="countryID" value="">

How do I use the rel attribute to populate the country, readonly, input field and, at the same time, populate the countryID hidden field with the unique country ID?

You mentioned "...populate the innerhtml of a span tag next to it." but don't we have to wait on the region selection by the user?

I understand I'll need an onchange event for the region select:
<select id="regionID" name="regionID" class="form-control" onchange="myFunction()">

I just don't have the knowledge to write the javascript function. I assume the function populates the country and countryID fields "onchange" of the region drop down.

Would appreciate any advice you could offer. Thank you Ray.
NJ

rel is just a random attribute... it could be anything. It sounds like you would want both the country name and ID in the option so that you could populate a hidden form element with the ID and the innerhtml of a span with the name.

So the code might look like:

<script>

function getCountryData(list) {

  var listOption = list.options[list.selectedIndex];

  var countryID = listOption.getAttribute("data-country-id");

  var countryName = listOption.getAttribute("data-country");

 document.getElementById("countryID").value = countryID;

 document.getElementById("showCountry").innerHTML= countryID;

}

</script>



<select id="regionID" name="regionID" class="form-control" onchange="getCountryData(this)">

<?php

while(!$rsREGIONS->atEnd()) {

?>

<option value="<?php echo($rsREGIONS->getColumnVal("regionID")); ?>" data-country="<?php echo($rsREGIONS->getColumnVal('country')); ?>" data-country-id="<?php echo($rsREGIONS->getColumnVal('country')); ?>"><?php echo($rsREGIONS->getColumnVal("region")); ?></option>

<?php

  $rsREGIONS->moveNext();

}

$rsREGIONS->moveFirst(); //return RS to first record

?>

</select>

<input type="hidden" id="countryID" name="countryID" value="">

<span id="showCountry"></span>

I've changed that to this as I think I spotted some errors:

php:

<script>
function getCountryData(list) {
  var listOption = list.options[list.selectedIndex];
  var countryID = listOption.getAttribute("data-country-id");
  var countryName = listOption.getAttribute("data-country");
 document.getElementById("countryID").value = countryID;
 document.getElementById("showCountry").innerHTML = countryName;
}
</script>

<select id="regionID" name="regionID" class="form-control" onchange="getCountryData(this)">
<?php
while(!$rsREGIONS->atEnd()) {
?>
<option value="<?php echo($rsREGIONS->getColumnVal("regionID")); ?>" data-country="<?php echo($rsREGIONS->getColumnVal['country']); ?>" data-country-id="<?php echo($rsREGIONS->getColumnVal['countryID']); ?>"><?php echo($rsREGIONS->getColumnVal("region")); ?></option>
<?php
  $rsREGIONS->moveNext();
}
$rsREGIONS->moveFirst(); //return RS to first record
?>
</select>
<input type="hidden" id="countryID" name="countryID" value="">
<span id="showCountry"></span>

That isn't populating the hidden field or displaying the country name though?

Do you have a url where I can view the page where you have tried?

Below, thank you.

Here's what I have on that page:

<script>
function getCountryData(list) {
  var listOption = list.options[list.selectedIndex];
  var countryID = listOption.getAttribute("data-country-id");
  var countryName = listOption.getAttribute("data-country");
 document.getElementById("tmsacountryID").value = countryID;
 document.getElementById("showCountry").innerHTML = countryName;
}
</script>
                    
                    <div class="form-group">
						<label for="tmsaregionID" class="col-sm-2 control-label">Region:</label>
						<div class="col-sm-6">
				          <select id="tmsaregionID" name="tmsaregionID" class="form-control" onchange="getCountryData(this)">
                          	<option value="0">Please select</option>
					      <?php
while(!$rsREGIONS->atEnd()) {
?>
					          <option value="<?php echo($rsREGIONS->getColumnVal("tmsaregionID")); ?>" data-country-id="<?php echo($rsREGIONS->getColumnVal['tmsacountryID']); ?>" data-country="<?php echo($rsREGIONS->getColumnVal['tmsacountry']); ?>"><?php echo($rsREGIONS->getColumnVal("tmsaregion")); ?></option>
					        <?php
  $rsREGIONS->moveNext();
}
$rsREGIONS->moveFirst(); //return RS to first record
?>
			              </select>
						</div>
					</div><!-- end form-group -->
                    
                    <div class="form-group">
						<label for="tmsacountryID" class="col-sm-2 control-label">Country:</label>
						<div class="col-sm-6">
                        <span id="showCountry"></span>
						<input type="text" class="form-control" id="tmsacountry" name="tmsacountry" readonly>
						<input type="text" id="tmsacountryID" name="tmsacountryID" value="">
						</div>
					</div><!-- end form-group -->

I changed this in your example:
document.getElementById("countryID").value = countryID;

To this...
document.getElementById("tmsacountryID").value = countryID;

..as I felt that must match the id of the form field. I've un-hidden them as well just so I can check they're working correctly.
Also, whilst I understand that <span id="showCountry"></span> will (should) display the country name, how do I get that value into my readonly form field?

Really appreciate the help, thank you. Was messing about with dynamic dropdowns for aaages before you pointed out the obvious!
NJ

It looks like the data isn't getting added to the options in the select list to begin with. Are you sure the columns tmsacountryID and tmsacountry are in the rsREGIONS recordset? Maybe you have to update your select statement to make sure those columns are available.

<?php
$rsREGIONS = new WA_MySQLi_RS("rsREGIONS",$csdbmysqli,0);
$rsREGIONS->setQuery("SELECT TMSAregions.tmsaregionID, TMSAregions.tmsaregion, TMSAregions.tmsamapsectionID, TMSAregions.tmsacountryID, TMSAcountry.tmsacountry FROM TMSAregions INNER JOIN TMSAcountry ON TMSAregions.tmsacountryID = TMSAcountry.tmsacountryID ORDER BY TMSAregions.tmsacountryID ASC, TMSAregions.tmsaregion ASC");
$rsREGIONS->execute();
?>

When I test that recordset in DW it displays the countryID and the country.

Ray, I just spotted single quotes around those values:

Originally Said By: Ray Borduin

  

php:

<option value="<?php echo($rsREGIONS->getColumnVal("regionID")); ?>" data-country="<?php echo($rsREGIONS->getColumnVal('country')); ?>" data-country-id="<?php echo($rsREGIONS->getColumnVal('country')); ?>"><?php echo($rsREGIONS->getColumnVal("region")); ?></option>

  

Should have been:
<option value="<?php echo($rsREGIONS->getColumnVal("regionID")); ?>" data-country="<?php echo($rsREGIONS->getColumnVal("tmsacountry")); ?>" data-country-id="<?php echo($rsREGIONS->getColumnVal("tmsacountryID")); ?>"><?php echo($rsREGIONS->getColumnVal("region")); ?></option>

That will teach me to cut and paste!
How do I get the <span id="showCountry"></span> value into the value of a form field?

Odd... when I view source on the page I see the select element code:

<select id="tmsaregionID" name="tmsaregionID" class="form-control" onchange="getCountryData(this)">
                          	<option value="0">Please select</option>
				<option value="3" data-country-id="" data-country="">Aberdeenshire</option>
				<option value="4" data-country-id="" data-country="">Angus</option>

You can see the country and country id are blank from the recordset. Is it possible the data isn't entered into the regions table properly? Do you see those field values when you test the recordset?

Maybe send me a copy of the page so I can take a look.