rails nested attributes ajax / javascript - ruby-on-rails-3

Question

I am trying to use the accepts_nested_attributes_for method based on the tutorial by Ryan Bates ( http://railscasts.com/episodes/196-nested-model-form-part-1 ).
For my form, however, I want to have a select list made up of the child elements so that the parent form has a list of children. I then want to dynamically add children and populate them to the select box via ajax. I want those children to be created even if the form submit is aborted.
question - is this possible?
thanks!
EDIT: I have the form populating with the children in the select already. The question is really whether the ajax portion will work. Is it possible to submit just a portion of a form?

Answer 1

Turns out I ended up using the jquery autocomplete combobox (http://jqueryui.com/demos/autocomplete/#combobox) with some modifications. Specifically, the change: function listed looks for invalid selections (which is our case if the user types into the combobox). Here's the default code from the widget:
...
change: function( event, ui ) {
if ( !ui.item ) {
...
});
if ( !valid ) {
// remove invalid value, as it didn't match anything
$( this ).val( "" );
select.val( "" );
input.data( "autocomplete" ).term = "";
return false;
}
}
}
...
and I changed it to:
...
change: function( event, ui ) {
if ( !ui.item ) {
...
});
if ( !valid ) {
var _new_text = $(this).val()
var _new_option = '<option value="'+_new_text+'">' + _new_text + '</option>'
select.prepend(_new_option);//append to combobox
//now let's select it for submission
select.children( "option" ).each(function(){
if( $(this).text().match(_new_text) ){
this.selected = true;
return false;
}
})
}
}
}
...
Not sure if there's a better way to do it, but this is where I'm at now! Now working on the filtering of the content in Rails, but that's another story.