Adding items to a selectOneListbox from Javascript

Question

In my JSF page I have...
<h:form id="alternateDeviceSelectForm">
    <h:selectOneListbox id="selectBox"/>
    <h:commandButton id="okButton" value="#{i18n.ok}" action="#{aBean.anActionMethod}"/>
</h:form>I also have this Javascript...
for (var i=0; i < devices.length; i++) {
    var device = devices;
// a String
var id = device.getId();
// another String
var displayName = device.getDisplayName();
this.selectBox.options[i] = new Option(displayName,id);
This creates the listbox and when the Javascript method fires, the appropriate items are listed in as list items.  However, when I hit the OK button, I get a JSF message about a validation error.  I'm not using any custom validation at all.
Here's the error message I get... "alternateDeviceSelectForm:selectBox: Validation Error: Value is not valid"
Any ideas on how I can get this working?  (I have to get the listbox item values from Javascript because that is the interface to a browser plugin that is involved in this process.)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Answer 1

dalearyous wrote:
the only thing is there is no data to begin with. after you choose the data structure there is a text field to type in something like apple and then you click add. then you can type in something like pear and click add.If you do it right, the part that controls the data structures won't need to directly interact with the part that adds/removes the elements in the data structures -- they'll be independent units. That's what we call "orthogonal", and it helps make programs much easier to develop and maintain. To do that, you have a common set of add/remove operations across all data structures -- just like in the Collections framework, which you should use unless your teacher is telling you that you must make your own. (And even if you do, ask your teacher if you can use the interfaces from the Collections framework, if not the implementations.)
The example I showed you supports that, in that it doesn't assume that the data structures initially contain any data. (Though it might be better to create empty Collections in your constructor, rather than ever letting existingCollection go null.