The composite is an element that it is composed of several elements and behaves like a single one. It is used like a view, but its inner workings are completely different. There are different types of composites and each one of them defines what are the elements it is composed of.
To create a composite, you have to call the function canvasUI.composite.new(id, type). The first argument is the id and the second argument is the type of composite. The returned value is the composite. That is an example:
const textArea = canvasUI.composite.new("textArea-1", "textArea")
In this example, we have created a composite in which the elements it is composed of are a text view and a frame layout.
Every composite has some properties that can be used to modify what are the elements it is composed of, how they are drawn and how they are placed. To change a property, you have to call the .set(property, value) method, like so:
textArea.set("background", "#567")