jQuery: change selectable dropdown options based on radio button selection

Question

I have a php web form, when user selects a radio button, I want only certain options to be available in the dropdown. So for example, if I select House fro

Answer 1

Simplest way is just assign css classes to the select options and show/hide them.

Demo: http://jsfiddle.net/9Tbpq/

<form method="post">
    <fieldset id="Group1" name="Group1">
        <legend>Group box</legend>
        <input id="Radio1" name="Radio1" type="radio" value="House" />House<br />
        <input id="Radio1" name="Radio1" type="radio" value="Condo" />Condo<br />
        <input id="Radio1" name="Radio1" type="radio" value="Boat" />Boat<br />
    </fieldset>
    <br/><br/>

    <fieldset id="Group2" name="Group2">
        <legend>Group Options</legend>
        <select id="Select1" name="Select1">
            <option>Select</option>
            <option value="HO-House 1">House 1</option>
            <option value="HO-House 2">House 2</option>
            <option value="HO-House 3">House 3</option>
            <option value="CO-Condo 1">Condo 1</option>
            <option value="CO-Condo 2">Condo 2</option>
            <option value="CO-Condo 3">Condo 3</option>
            <option value="BO-Boat 1">Boat 1</option>
            <option value="BO-Boat 2">Boat 2</option>
            <option value="BO-Boat 3">Boat 3</option>
        </select>
    </fieldset>
</form>​

.

<script>
jQuery(function($) {
    $('input:radio').change(function(){
        var val = $('input:radio:checked').val();
        console.log(val)
        $('#Select1').val(0)
        $('option[value]').hide();
        $('option[value*="-' + val + '"]').show();
    });
});​
</script>

Answer 2

You have two elements with an id of "Radio1." You should probably change that.

Code is here: http://jsfiddle.net/kkk7J/5/

//record of temporarily removed  options
var oldoptions = [];

$("[type=radio]").on('click', function () {
   //add all filtered options back
   $("#Select1").append(oldoptions);

   //Remove any option whose text does not contain the text of the selected
   //radio button
   oldoptions = $("#Select1 option:not(:contains(" + $(this).val() + "))").detach();
});​

Detaching the elements is necessary because not all browsers support hiding <option>. Additionally, at least some browsers will keep the currently selected option even if it becomes hidden. These are both solved easily by detaching.

Answer 3

It could look like this:

$(function(){

    var select = $('#Select1'),
        options = select.find('option');

    $('[type="radio"]').click(function(){
        var visibleItems = options.filter('[value*="' + $(this).val()  + '"]').show();
        options.not(visibleItems).hide();

        if(visibleItems.length > 0)
        {
            select.val(visibleItems.eq(0).val());
        }
    });
});​

Demo: http://jsfiddle.net/kkk7J/2/