bs.set.md

[@bs.set]

bs.set is used to set a property of an object.

For example, say you created a div element:

type element;
[@bs.scope "document"] [@bs.val] external createElement: string => element = "";

let div = createElement("div");

How can we set its properties, e.g. scrollTop?

Doing this doesn't work:

div.scrollTop = 100; // Error: The record field scrollTop can't be found.

That's what bs.set is for:

[@bs.set] external setScrollTop: (element, int) => unit = "scrollTop";

setScrollTop(div, 100);

which compiles to:

div.scrollTop = 100;

Note how we defined scrollTop as a function that takes an element and a value, and BS compiled it to element.scrollTop = value.