Add Model#legacyPrepare

CHANGELOG.md

@@ -8,6 +8,7 @@
     - Changed `ViewModel#setData()` to no longer accept a `context` argument or change the context
     - Changed `ViewModel#setDataProgress()` to no longer change the context, despite accepting `context` argument
     - Updated `ViewModel` to trigger a render when the `context` event is fired
+- Added `Model#legacyPrepare` readonly property to indicate whether the legacy `prepare` method is used or the new `setup()` method
 - Added the `EmbedApp#publicApi.setLocationSync()` method to simplify sync between the embed app and the host location, preventing potential pitfalls
 - Added `ViewModel#enforceScheduledRenders()` to immediately execute scheduled renders
 - Changed `ViewModel#scheduleRender()` to use `setTimeout()` instead of `Promise.resolve()` to ensure proper processing of event loop tasks, eliminating unnecessary renders

src/main/model.ts

@@ -241,6 +241,9 @@ export class Model<
     // Data & context
     //
 
+    get legacyPrepare() {
+        return this.#legacyPrepare;
+    }
     setPrepare(fn: PrepareFunction) {
         if (typeof fn !== 'function') {
             throw new Error('An argument should be a function');