Create custom.js

inst/app/www/custom.js

@@ -0,0 +1,25 @@
+function ts(cb) {
+  if (cb.readOnly) cb.checked=cb.readOnly=false;
+  else if (!cb.checked) cb.readOnly=cb.indeterminate=true;
+}
+
+var customCheckbox = new Shiny.InputBinding();
+
+$.extend(customCheckbox, {
+  find: function(scope) {
+    return $(scope).find("input[type='checkbox'].cs_checkbox");
+  },
+  getValue: function(el) {
+    return el.checked;
+  },
+  subscribe: function(el, callback) {
+    $(el).on("change.checkboxInputBinding", function() {
+      Shiny.onInputChange($(this).attr('id'), this.checked, {priority: 'event'});
+    });
+  },
+  unsubscribe: function(el) {
+    $(el).off(".checkboxInputBinding");
+  }
+});
+
+Shiny.inputBindings.register(customCheckbox);