Coming from using a different reactive, backend-driven framework, I am used to being able to send arbitrary data using a simple javascript api. The library in question is Livewire, built for the PHP framework, Laravel. They include a js lib which creates some directives to help you along the way and can do things like:

<script>
 const datepicker = document.getElementById('datepicker');
 DatePickerLibrary('#datepicker', {
 onUpdate: (value) => $wire.set('date', value)
 })
 
 // Their js util library provides "$wire" function to perform, in this case, an ajax call to update the backend
 // You could as well do this:
 $wire.set('name', name) // set's the server-side property
</script>

Trying to create some interactive form fields and components with idom I feel something like this will be really useful.

Is there anything that exists already that may achieve something similar - setting backend properties via some javascript call?