Thanks for your question.
The widget you're talking about is actually not an official jQuery UI
plugin, but rather a custom widget by Filament Group.
Reference article here:
http://www.filamentgroup.com/lab/date_range_picker_using_jquery_ui_16_and_jquery_ui_css_framework/
To answer your question, you can probably do what you're attempting by
using the plugin's "datepickerOptions" option, which is just a way to
get to the options for each jQuery UI datepicker widget in the
rangepicker. You could use the datepicker's onSelect callbac, check
the second input's value and if it is empty, populate it with the
value from the first input.
Something like....
$('#inputA, #inputB').daterangepicker( {
datepickerOptions: {
onSelect: function(dateText) {
if($('#inputB').val() == ""){
$('#inputB').val(dateText);
}
}
}
});
In the future, please post a comment on that article page so your
question will be seen by the right people.
-Scott, Filament Group