Create a TypeScript-Compatible Widget

Creates a reference class-based widget that can interact with TypeScript code. The widget supports reactive properties that can be observed from both R and TypeScript, with automatic state synchronization.

Usage

createWidget(
  name,
  properties = list(),
  initialize = NULL,
  methods = list(),
  auto_flush = TRUE,
  .env = parent.frame(),
  ...
)

Arguments

name

Character string specifying the name of the widget class

properties

Named list of typed properties for the widget. Each property should be a TypeScript type object that defines the property's type

initialize

Optional initialization function that receives the widget instance and sets up initial state

methods

Named list of methods to add to the widget class. Each method should be a ts_function object

auto_flush

Logical, if TRUE (default), widget methods automatically flush state changes to TypeScript after execution. If FALSE, manual updateState() calls are required.

.env

Environment where the ref class should be created. Defaults to parent.frame() which is the caller's environment (typically unlocked). Can be overridden (e.g., to .GlobalEnv) if needed.

...

Additional arguments passed to the TypeScript function constructor

Value

A TypeScript function constructor that creates widget instances with reactive properties and methods for TypeScript interoperability

Details

Note that the object constructed takes a Javascript setter function as argument, so calling obj$call() will fail.

The created widget includes built-in methods:

• set(prop, value): Set a property value and mark it as changed

• get(prop): Get a property value

• addPropHandler(prop, fn): Register a handler for property changes

• updateState(all = FALSE): Synchronize changed properties to TypeScript

Each property automatically gets TypeScript-accessible methods:

• register(fn): Register a callback for property changes

• get(): Get the current property value

• set(x): Set the property value

Examples

# Create a simple counter widget
if (FALSE) { # \dontrun{
createWidget(
    name = "Counter",
    properties = list(count = ts_integer(1)),
    initialize = function(widget) {
        widget$set("count", 0)
    }
)
} # }