feat(useOverlay): add isOpen method to check overlay state (#4041)

docs/app/components/content/examples/modal/ModalProgrammaticExample.vue

@@ -13,7 +13,9 @@ const modal = overlay.create(LazyModalExample, {
 })
 
 async function open() {
-  const shouldIncrement = await modal.open()
+  const instance = modal.open()
+
+  const shouldIncrement = await instance.result
 
   if (shouldIncrement) {
     count.value++

docs/app/components/content/examples/slideover/SlideoverProgrammaticExample.vue

@@ -13,7 +13,9 @@ const slideover = overlay.create(LazySlideoverExample, {
 })
 
 async function open() {
-  const shouldIncrement = await slideover.open()
+  const instance = slideover.open()
+
+  const shouldIncrement = await instance.result
 
   if (shouldIncrement) {
     count.value++

docs/content/2.composables/use-overlay.md

@@ -66,6 +66,13 @@ Update an overlay using its `id`
 
 Removes the overlay from the DOM using its `id`
 
+- Parameters:
+  - `id`: The identifier of the overlay
+
+### `isOpen(id: symbol): boolean`
+
+Checks if an overlay its open using its `id`
+
 - Parameters:
   - `id`: The identifier of the overlay