Bug 1469592 - Add support for Element.toggleAttribute. r=bzbarsky,smaug!

MozReview-Commit-ID: KkDLMlQgESs

Differential Revision: https://phabricator.services.mozilla.com/D1710

--HG--
extra : moz-landing-system : lando

dom/base/Element.cpp

@@ -1321,6 +1321,43 @@ Element::GetAttribute(const nsAString& aName, DOMString& aReturn)
   }
 }
 
+bool
+Element::ToggleAttribute(const nsAString& aName,
+                         const Optional<bool>& aForce,
+                         nsIPrincipal* aTriggeringPrincipal,
+                         ErrorResult& aError)
+{
+  aError = nsContentUtils::CheckQName(aName, false);
+  if (aError.Failed()) {
+    return false;
+  }
+
+  nsAutoString nameToUse;
+  const nsAttrName* name = InternalGetAttrNameFromQName(aName, &nameToUse);
+  if (!name) {
+    if (aForce.WasPassed() && !aForce.Value()) {
+      return false;
+    }
+    RefPtr<nsAtom> nameAtom = NS_AtomizeMainThread(nameToUse);
+    if (!nameAtom) {
+      aError.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return false;
+    }
+    aError = SetAttr(kNameSpaceID_None, nameAtom, EmptyString(), aTriggeringPrincipal, true);
+    return true;
+  }
+  if (aForce.WasPassed() && aForce.Value()) {
+    return true;
+  }
+  // Hold a strong reference here so that the atom or nodeinfo doesn't go
+  // away during UnsetAttr. If it did UnsetAttr would be left with a
+  // dangling pointer as argument without knowing it.
+  nsAttrName tmp(*name);
+
+  aError = UnsetAttr(name->NamespaceID(), name->LocalName(), true);
+  return false;
+}
+
 void
 Element::SetAttribute(const nsAString& aName,
                       const nsAString& aValue,

dom/base/Element.h

@@ -1101,6 +1101,8 @@ public:
   void GetAttributeNS(const nsAString& aNamespaceURI,
                       const nsAString& aLocalName,
                       nsAString& aReturn);
+  bool ToggleAttribute(const nsAString& aName, const Optional<bool>& aForce,
+                       nsIPrincipal* aTriggeringPrincipal, ErrorResult& aError);
   void SetAttribute(const nsAString& aName, const nsAString& aValue,
                     nsIPrincipal* aTriggeringPrincipal, ErrorResult& aError);
   void SetAttributeNS(const nsAString& aNamespaceURI,

dom/webidl/Element.webidl

@@ -41,6 +41,8 @@ interface Element : Node {
   [Pure]
   DOMString? getAttributeNS(DOMString? namespace, DOMString localName);
   [CEReactions, NeedsSubjectPrincipal=NonSystem, Throws]
+  boolean toggleAttribute(DOMString name, optional boolean force);
+  [CEReactions, NeedsSubjectPrincipal=NonSystem, Throws]
   void setAttribute(DOMString name, DOMString value);
   [CEReactions, NeedsSubjectPrincipal=NonSystem, Throws]
   void setAttributeNS(DOMString? namespace, DOMString name, DOMString value);

testing/web-platform/tests/interfaces/dom.idl

@@ -360,6 +360,7 @@ interface Element : Node {
   void setAttributeNS(DOMString? namespace, DOMString qualifiedName, DOMString value);
   void removeAttribute(DOMString qualifiedName);
   void removeAttributeNS(DOMString? namespace, DOMString localName);
+  boolean toggleAttribute(DOMString qualifiedName, optional boolean force);
   boolean hasAttribute(DOMString qualifiedName);
   boolean hasAttributeNS(DOMString? namespace, DOMString localName);