Dynamically setting default in crosstalk filter with Javascript works for one variable, but not the other

In your "working as expected" 2015 and Jan are quoted:

function filterdefault(){
  document.getElementById("yearfilter").getElementsByClassName("selectized")[0].selectize.setValue("2015",false)
  document.getElementById("monthfilter").getElementsByClassName("selectized")[0].selectize.setValue("Jan",false)
}
$(document).ready(filterdefault);

they way you pass variables to JS, 2015 and Jan are not quoted. 2015 works since it's an integer, but Jan is an undefined variable.

> tags$script(HTML('
+ function filterdefault(){
+   document.getElementById("yearfilter").getElementsByClassName("selectized")[0].selectize.setValue(',defaultyear,',false)
+   document.getElementById("monthfilter").getElementsByClassName("selectized")[0].selectize.setValue(',defaultmonth,',false)
+ }
+ $(document).ready(filterdefault);
+ '))
function filterdefault(){
  document.getElementById("yearfilter").getElementsByClassName("selectized")[0].selectize.setValue( 2015 ,false)
  document.getElementById("monthfilter").getElementsByClassName("selectized")[0].selectize.setValue( Jan ,false)
}
$(document).ready(filterdefault);

So possible fixes could be sprintf

js