How to attach OCaml values to DOM elements?

It is often convenient to attach OCaml values to certain elements of the page. There are several ways to achieve this.

• The first possibility is to use DATA attributes (for example if the page is generated on server side).
• Alternatively, you can add a new property to the element using the ##. syntax.
  • You can create a new class type with the new property (that can be either an OCaml value or a JS value), possibly inheriting from the type of the DOM element, and create an (unsafe) coercion function for this type; or simply
  • Create getter and setter functions to add the new property.