Global non-persisted state with useEmailSelection composition function

src/composition/useEmailSelection.js

@@ -0,0 +1,19 @@
+import { reactive } from 'vue';
+
+let emails = new Set() 
+export const useEmailSelection = function(){
+  let emailSelection = reactive({
+    emails: emails,
+    toggle(id) {
+      if(this.emails.has(id)) {
+        this.emails.delete(id)
+      } else {
+        this.emails.add(id);
+      }
+    },
+  })
+
+  return { emailSelection }
+}
+
+export default useEmailSelection;