[Feature] Dialog: use native <dialog> element (#343)

Replace the template-clone pattern with a native <dialog> element.
DialogContent now renders as <dialog> opened via showModal() and closed
via close(), gaining free top-layer rendering, native backdrop, built-in
focus trapping, and Esc-to-close. Body scroll-lock is preserved. All
existing public component API and Stimulus controller actions are
backward-compatible.

Author: djalmaaraujo

gem/lib/ruby_ui/dialog/dialog_content.rb

@@ -17,24 +17,20 @@ def initialize(size: :md, **attrs)
     end
 
     def view_template
-      template(data: {ruby_ui__dialog_target: "content"}) do
-        div(data_controller: "ruby-ui--dialog") do
-          backdrop
-          div(**attrs) do
-            yield
-            close_button
-          end
-        end
+      dialog(**attrs) do
+        yield
+        close_button
       end
     end
 
     private
 
     def default_attrs
       {
-        data_state: "open",
+        data_ruby_ui__dialog_target: "dialog",
+        data_action: "click->ruby-ui--dialog#backdropClick",
         class: [
-          "fixed flex flex-col pointer-events-auto left-[50%] top-[50%] z-50 w-full max-h-screen overflow-y-auto translate-x-[-50%] translate-y-[-50%] gap-4 border bg-background p-6 shadow-lg duration-200 data-[state=open]:animate-in data-[state=open]:fade-in-0 data-[state=open]:zoom-in-95 sm:rounded-lg md:w-full",
+          "fixed flex flex-col pointer-events-auto left-[50%] top-[50%] z-50 w-full max-h-screen overflow-y-auto translate-x-[-50%] translate-y-[-50%] gap-4 border bg-background p-6 shadow-lg duration-200 backdrop:bg-background/80 backdrop:backdrop-blur-sm open:animate-in open:fade-in-0 open:zoom-in-95 sm:rounded-lg md:w-full",
           SIZES[@size]
         ]
       }
@@ -43,7 +39,7 @@ def default_attrs
     def close_button
       button(
         type: "button",
-        class: "absolute end-4 top-4 rounded-sm opacity-70 ring-offset-background transition-opacity hover:opacity-100 focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2 disabled:pointer-events-none data-[state=open]:bg-accent data-[state=open]:text-muted-foreground",
+        class: "absolute end-4 top-4 rounded-sm opacity-70 ring-offset-background transition-opacity hover:opacity-100 focus:outline-none focus:ring-2 focus:ring-ring focus:ring-offset-2 disabled:pointer-events-none",
         data_action: "click->ruby-ui--dialog#dismiss"
       ) do
         svg(
@@ -65,13 +61,5 @@ def close_button
         span(class: "sr-only") { "Close" }
       end
     end
-
-    def backdrop
-      div(
-        data_state: "open",
-        data_action: "click->ruby-ui--dialog#dismiss esc->ruby-ui--dialog#dismiss",
-        class: "fixed pointer-events-auto inset-0 z-50 bg-background/80 backdrop-blur-sm data-[state=open]:animate-in data-[state=open]:fade-in-0"
-      )
-    end
   end
 end

gem/lib/ruby_ui/dialog/dialog_controller.js

@@ -1,8 +1,8 @@
 import { Controller } from "@hotwired/stimulus"
 
-// Connects to data-controller="dialog"
+// Connects to data-controller="ruby-ui--dialog"
 export default class extends Controller {
-  static targets = ["content"]
+  static targets = ["dialog"]
   static values = {
     open: {
       type: Boolean,
@@ -11,22 +11,33 @@ export default class extends Controller {
   }
 
   connect() {
+    this.dialogTarget.addEventListener("close", this.handleClose)
     if (this.openValue) {
       this.open()
     }
   }
 
+  disconnect() {
+    this.dialogTarget.removeEventListener("close", this.handleClose)
+  }
+
   open(e) {
-    e?.preventDefault();
-    document.body.insertAdjacentHTML('beforeend', this.contentTarget.innerHTML)
-    // prevent scroll on body
-    document.body.classList.add('overflow-hidden')
+    e?.preventDefault()
+    this.dialogTarget.showModal()
+    document.body.classList.add("overflow-hidden")
   }
 
   dismiss() {
-    // allow scroll on body
-    document.body.classList.remove('overflow-hidden')
-    // remove the element
-    this.element.remove()
+    this.dialogTarget.close()
+  }
+
+  backdropClick(e) {
+    if (e.target === this.dialogTarget) {
+      this.dismiss()
+    }
+  }
+
+  handleClose = () => {
+    document.body.classList.remove("overflow-hidden")
   }
 }

gem/test/ruby_ui/dialog_test.rb

@@ -33,4 +33,92 @@ def test_render_with_all_items
 
     assert_match(/Open Dialog/, output)
   end
+
+  # Regression test for #343: Dialog content must use native <dialog> element, not <div>
+  def test_dialog_content_renders_native_dialog_element
+    output = phlex do
+      RubyUI.Dialog do
+        RubyUI.DialogContent { "Content" }
+      end
+    end
+
+    assert_match(/<dialog[\s>]/, output, "DialogContent must render a native <dialog> element")
+    refute_match(/<template[\s>]/, output, "DialogContent must not use a <template> element")
+  end
+
+  def test_dialog_wrapper_renders_as_div_with_stimulus_controller
+    output = phlex do
+      RubyUI.Dialog do
+        RubyUI.DialogContent { "Content" }
+      end
+    end
+
+    assert_match(/data-controller="ruby-ui--dialog"/, output)
+    assert_match(/<div[^>]*data-controller="ruby-ui--dialog"/, output, "Dialog wrapper must be a <div>")
+  end
+
+  def test_dialog_content_has_stimulus_target
+    output = phlex do
+      RubyUI.Dialog do
+        RubyUI.DialogContent { "Content" }
+      end
+    end
+
+    assert_match(/data-ruby-ui--dialog-target="dialog"/, output)
+  end
+
+  def test_dialog_content_has_backdrop_click_action
+    output = phlex do
+      RubyUI.Dialog do
+        RubyUI.DialogContent { "Content" }
+      end
+    end
+
+    assert_match(/data-action="click->ruby-ui--dialog#backdropClick"/, output)
+  end
+
+  def test_dialog_content_sizes
+    {xs: "max-w-sm", sm: "max-w-md", md: "max-w-lg", lg: "max-w-2xl", xl: "max-w-4xl", full: "max-w-full"}.each do |size, expected_class|
+      output = phlex do
+        RubyUI.Dialog do
+          RubyUI.DialogContent(size: size) { "Content" }
+        end
+      end
+
+      assert_match(/#{Regexp.escape(expected_class)}/, output, "Size #{size} should apply class #{expected_class}")
+    end
+  end
+
+  def test_dialog_open_value_is_set_on_wrapper
+    output = phlex do
+      RubyUI.Dialog(open: true) do
+        RubyUI.DialogContent { "Content" }
+      end
+    end
+
+    assert_match(/data-ruby-ui--dialog-open-value/, output)
+  end
+
+  def test_close_button_has_dismiss_action
+    output = phlex do
+      RubyUI.Dialog do
+        RubyUI.DialogContent { "Content" }
+      end
+    end
+
+    assert_match(/data-action="click->ruby-ui--dialog#dismiss"/, output)
+  end
+
+  def test_trigger_has_open_action
+    output = phlex do
+      RubyUI.Dialog do
+        RubyUI.DialogTrigger do
+          RubyUI.Button { "Open" }
+        end
+        RubyUI.DialogContent { "Content" }
+      end
+    end
+
+    assert_match(/data-action="click->ruby-ui--dialog#open"/, output)
+  end
 end