Bug 1934825, part 2 - Text Fragments: Create chrome-only API to create text directives from a range. r=farre

Differential Revision: https://phabricator.services.mozilla.com/D231100

dom/base/FragmentDirective.cpp

@@ -16,6 +16,7 @@
 #include "mozilla/dom/BrowsingContextGroup.h"
 #include "mozilla/dom/FragmentDirectiveBinding.h"
 #include "mozilla/dom/FragmentOrElement.h"
+#include "mozilla/dom/Promise.h"
 #include "mozilla/dom/Selection.h"
 #include "mozilla/PresShell.h"
 #include "nsContentUtils.h"
@@ -421,5 +422,26 @@ void FragmentDirective::RemoveAllTextDirectives(ErrorResult& aRv) {
   }
   targetTextSelection->RemoveAllRanges(aRv);
 }
+already_AddRefed<Promise> FragmentDirective::CreateTextDirective(
+    nsRange& aRange) {
+  RefPtr<Promise> resultPromise =
+      Promise::Create(mDocument->GetOwnerGlobal(), IgnoreErrors());
+  if (!resultPromise) {
+    return nullptr;
+  }
+  if (!StaticPrefs::dom_text_fragments_create_text_fragment_enabled() ||
+      !StaticPrefs::dom_text_fragments_enabled()) {
+    TEXT_FRAGMENT_LOG("Creating text fragments is disabled.");
+    resultPromise->MaybeResolve(JS::NullHandleValue);
+    return resultPromise.forget();
+  }
+  if (aRange.Collapsed()) {
+    TEXT_FRAGMENT_LOG("Collapsed range. Nothing to do here...");
+    resultPromise->MaybeResolve(JS::NullHandleValue);
+    return resultPromise.forget();
+  }
+
+  return resultPromise.forget();
+}
 
 }  // namespace mozilla::dom

dom/base/FragmentDirective.h

@@ -20,6 +20,7 @@ class nsIURI;
 class nsRange;
 namespace mozilla::dom {
 class Document;
+class Promise;
 class Text;
 class TextDirectiveFinder;
 
@@ -137,6 +138,15 @@ class FragmentDirective final : public nsISupports, public nsWrapperCache {
    */
   MOZ_CAN_RUN_SCRIPT void RemoveAllTextDirectives(ErrorResult& aRv);
 
+  /** Creates a text directive string from a given range.
+   *
+   * @param aRange  The input range.
+   *
+   * @return Returns the created text directive as resolved promise, or a
+   *         rejected promise in case of an error.
+   */
+  already_AddRefed<Promise> CreateTextDirective(nsRange& aRange);
+
  private:
   RefPtr<Document> mDocument;
   UniquePtr<TextDirectiveFinder> mFinder;

dom/webidl/FragmentDirective.webidl

@@ -13,4 +13,7 @@ interface FragmentDirective {
 
     [Pref="dom.text_fragments.enabled", ChromeOnly, Throws]
     undefined removeAllTextDirectives();
+
+    [Pref="dom.text_fragments.create_text_fragment.enabled", ChromeOnly]
+    Promise<DOMString> createTextDirective(Range range);
 };