AboutAnthony Levensalor Experience I have been programming in Java and Javascript since 1998. I run a web development company that specializes in Ajax front ends with PHP/MySQL back ends. I am a Sun Certified Java 2 Developer, and have done nothing but web applications for the last two years in my business
Past/Present clients Monster.com, Compuware Corporation, Flextronics International, Pragmatech Software, Open Travel Software, The Loss Mitigation Institute, Raw Story Media, Page One News Media.
Expert: Anthony Levensalor Date: 1/14/2008 Subject: Force a ListBox Selection From another Field
Question This is a Acrobat Form.
Is there a way to force a selection in a ListBox from another field?
If radio button 1 is selected then the contents of text box 1 is the value we want selected in the ListBox.
If radio button 2 is selected then the contents of text box 2 is the value we want selected in the ListBox.
If radio button 3 is selected then the contents of text box 3 is the value we want selected in the ListBox.
The contents of the text boxes are values that are in the ListBox data.
Both the ListBox and the text boxes are being populated from external databases.
Any and all advice is welcome.
Answer Yes, there absolutely is, and it's actually pretty easy once you get it the first time.
Given
3 input elements of type radio
3 input elements of type text
1 select element
We could write the following code that would select the value in the select element when the radio buttons were clicked to the select element matching the text:
(Comments are in the source below, which you can copy directly to an empty file to see it work)
<html>
<head>
<script type="text/javascript">
// This function takes an event as its only parameter
function updateSelect(e) {
// Here, we use object detection to make sure it will work across browsers
e = e || window.event
// Here, we get the element that fired the event.
// Again, we use object detection to make sure it works
// across multiple environments
var elm = e.target || e.srcElement
// In the HTML, we have used a simple naming scheme to
// match radios to their text field. Here,
// we use that naming scheme
var txtElmId = elm.id.replace("radio", "txt")
// And then grab the right fields value
var textValue = document.getElementById(txtElmId).value
// Here we just get the reference to the select element
var selectElm = document.getElementById('main_list')
// oLen will hold the nunber of options in the list
var oLen = selectElm.options.length
// Here we loop through the options, matching the text of
// the text input to the select input options
for (var i = 0; i < oLen; ++i) {
if (selectElm.options[i].text == textValue) {
selectElm.value = selectElm.options[i].value
break;
}
}
} // updateSelect
// This function sets the even handlers.
// It fires on the load event of the main body
function init() {
if (document.getElementById("radioThree")) {
document.getElementById("radioOne").onclick = updateSelect
document.getElementById("radioTwo").onclick = updateSelect
document.getElementById("radioThree").onclick = updateSelect
} else {
// We're using setTimeout here to make sure the elements
// are avilable for use. If this function were to fire
// before the elements fully load, it will wait and re-fire
// in ten milliseconds. It will keep doing this until the
// elements we want are usable
setTimeout(init, 10)
}
}
