postprocess.html

<div class="compendium-drop-target">
  <input type="hidden" name="attr_ImportedComponents" accept="Components" />
  <input type="checkbox" value="1" name="attr_ComponentV" /> V
</div>

<script type="text/worker">
on("change:ImportedComponents", function() {
    getAttrs(["ImportedComponents"], function(data) {
       var splitComponents = data.ImportedComponents.split(" ");
       var attrsToSet = {};
       if(splitComponents.indexOf("V") !== -1) {
         attrsToSet["ComponentV"] = "1";
       }
       setAttrs(attrsToSet);
    });
});
</script>