From 46b6faa6b26bdd008d5d7f9eb7451bd73bab5b32 Mon Sep 17 00:00:00 2001
From: Cameron Kaiser <classilla@floodgap.com>
Date: Sun, 11 Feb 2018 13:21:45 -0800
Subject: [PATCH] closes #472: Element.insertAdjacentText
 Element.insertAdjacentElement

---
 dom/base/Element.cpp      | 49 +++++++++++++++++++++++++++++++++++++++
 dom/base/Element.h        | 20 ++++++++++++++++
 dom/webidl/Element.webidl |  6 +++++
 3 files changed, 75 insertions(+)

diff --git a/dom/base/Element.cpp b/dom/base/Element.cpp
index ba8d232630..51f6860ff9 100644
--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -3556,6 +3556,55 @@ Element::InsertAdjacentHTML(const nsAString& aPosition, const nsAString& aText,
   }
 }
 
+nsINode*
+Element::InsertAdjacent(const nsAString& aWhere,
+                        nsINode* aNode,
+                        ErrorResult& aError)
+{
+  if (aWhere.LowerCaseEqualsLiteral("beforebegin")) {
+    nsCOMPtr<nsINode> parent = GetParentNode();
+    if (!parent) {
+      return nullptr;
+    }
+    parent->InsertBefore(*aNode, this, aError);
+  } else if (aWhere.LowerCaseEqualsLiteral("afterbegin")) {
+    nsCOMPtr<nsINode> refChild = GetFirstChild();
+    static_cast<nsINode*>(this)->InsertBefore(*aNode, refChild, aError);
+  } else if (aWhere.LowerCaseEqualsLiteral("beforeend")) {
+    static_cast<nsINode*>(this)->AppendChild(*aNode, aError);
+  } else if (aWhere.LowerCaseEqualsLiteral("afterend")) {
+    nsCOMPtr<nsINode> parent = GetParentNode();
+    if (!parent) {
+      return nullptr;
+    }
+    nsCOMPtr<nsINode> refChild = GetNextSibling();
+    parent->InsertBefore(*aNode, refChild, aError);
+  } else {
+    aError.Throw(NS_ERROR_DOM_SYNTAX_ERR);
+    return nullptr;
+  }
+
+  return aError.Failed() ? nullptr : aNode;
+}
+
+Element*
+Element::InsertAdjacentElement(const nsAString& aWhere,
+                               Element& aElement,
+                               ErrorResult& aError) {
+  nsINode* newNode = InsertAdjacent(aWhere, &aElement, aError);
+  MOZ_ASSERT(!newNode || newNode->IsElement());
+
+  return newNode ? newNode->AsElement() : nullptr;
+}
+
+void
+Element::InsertAdjacentText(
+  const nsAString& aWhere, const nsAString& aData, ErrorResult& aError)
+{
+  RefPtr<nsTextNode> textNode = OwnerDoc()->CreateTextNode(aData);
+  InsertAdjacent(aWhere, textNode, aError);
+}
+
 nsIEditor*
 Element::GetEditorInternal()
 {
diff --git a/dom/base/Element.h b/dom/base/Element.h
index f0c431c367..71c1614cd8 100644
--- a/dom/base/Element.h
+++ b/dom/base/Element.h
@@ -708,6 +708,26 @@ class Element : public FragmentOrElement
                            ErrorResult& aError);
   already_AddRefed<nsIHTMLCollection>
     GetElementsByClassName(const nsAString& aClassNames);
+
+private:
+  /**
+   * Implement the algorithm specified at
+   * https://dom.spec.whatwg.org/#insert-adjacent for both
+   * |insertAdjacentElement()| and |insertAdjacentText()| APIs.
+   */
+  nsINode* InsertAdjacent(const nsAString& aWhere,
+                          nsINode* aNode,
+                          ErrorResult& aError);
+
+public:
+  Element* InsertAdjacentElement(const nsAString& aWhere,
+                                 Element& aElement,
+                                 ErrorResult& aError);
+
+  void InsertAdjacentText(const nsAString& aWhere,
+                          const nsAString& aData,
+                          ErrorResult& aError);
+
   void SetPointerCapture(int32_t aPointerId, ErrorResult& aError)
   {
     bool activeState = false;
diff --git a/dom/webidl/Element.webidl b/dom/webidl/Element.webidl
index 7c485aca9b..984e37f50b 100644
--- a/dom/webidl/Element.webidl
+++ b/dom/webidl/Element.webidl
@@ -71,6 +71,12 @@ interface Element : Node {
   [Pure]
   HTMLCollection getElementsByClassName(DOMString classNames);
 
+  [Throws, Pure]
+  Element? insertAdjacentElement(DOMString where, Element element); // historical
+
+  [Throws]
+  void insertAdjacentText(DOMString where, DOMString data); // historical
+
   /**
    * The ratio of font-size-inflated text font size to computed font
    * size for this element. This will query the element for its primary frame,