Sending another select value as a parameter with form post

I have a form with a select element that contains a list of categories populated from an external source. When I submit the form I want to be able to post parameters for the value for the option selected (category_id), this works as expected. However I also want to pass a second parameter (category_name) which is currently the text of the select option.

For the sake of clarity below is a very simple representation of the select element:

<select name="category_id" id="category_id">
<option value='1'>All</option>
    <option value='2'>Category 1</option>
    <option value='3'>Category 2</option>
</select> 

I was wondering what the best way of doing this is. Do I need to use Javascript or is there some way of doing this via 开发者_JAVA百科HTML? For what its worth Im using Rails to build the app so if there is a smart way to do this using the framework that would also be very useful to know.

Thanks in advance for the help.

Dave

---

You could either change the value so it contains both values then just split them on the server:

<select name="category_id" id="category_id">
    <option value='1|All'>All</option>
    <option value='2|Category 1'>Category 1</option>
    <option value='3|Category 2'>Category 2</option>
</select> 

Or use some javascript and update a hidden field:

HTML

<select name="category_id" id="category_id">
    <option value='1'>All</option>
    <option value='2'>Category 1</option>
    <option value='3'>Category 2</option>
</select> 
<input type="hidden" id="category_name" name="category_name" />

JS

function updateNameValue() {
    $('#category_name').val($('#category_id option:selected').text());
}

$('#category_id').change(updateNameValue);

updateNameValue(); // Call function here to make sure initial value is set

http://jsfiddle.net/6runZ/