From 68b04d5c78612ea03d1df0014c107340f817b6d7 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Wed, 25 Mar 2020 18:53:20 +0100
Subject: [PATCH] LibWeb: Implement getting and setting element.innerHTML

Getting the innerHTML property will recurse through the subtree inside
the element and serialize it into a string as it goes.

Setting it will parse the set value as an HTML fragment. It will then
remove all current children of the element and replace them with all
the children inside the parsed fragment.

Setting element.innerHTML will currently force a complete rebuild of
the document's layout tree.

This is pretty neat! :^)
---
 Base/home/anon/www/innerHTML.html             | 17 +++++
 Base/home/anon/www/welcome.html               |  1 +
 Libraries/LibWeb/Bindings/ElementWrapper.cpp  | 65 +++++++++++++++++++
 Libraries/LibWeb/Bindings/ElementWrapper.h    | 47 ++++++++++++++
 .../Bindings/HTMLCanvasElementWrapper.cpp     |  2 +-
 .../Bindings/HTMLCanvasElementWrapper.h       |  4 +-
 Libraries/LibWeb/Bindings/NodeWrapper.cpp     |  2 +
 Libraries/LibWeb/DOM/Element.cpp              | 52 ++++++++++++++-
 Libraries/LibWeb/DOM/Element.h                |  5 ++
 Libraries/LibWeb/Forward.h                    |  1 +
 Libraries/LibWeb/Makefile                     |  1 +
 11 files changed, 192 insertions(+), 5 deletions(-)
 create mode 100644 Base/home/anon/www/innerHTML.html
 create mode 100644 Libraries/LibWeb/Bindings/ElementWrapper.cpp
 create mode 100644 Libraries/LibWeb/Bindings/ElementWrapper.h
diff --git a/Base/home/anon/www/innerHTML.html b/Base/home/anon/www/innerHTML.html
new file mode 100644
index 0000000000..9bd382d497
--- /dev/null
+++ b/Base/home/anon/www/innerHTML.html
@@ -0,0 +1,17 @@
+<!DOCTYPE>
+<html>
+<head>
+</head>
+<body>
+<div id=clicky style="background-color: red; color: white; border: 1px solid black;">Click me</div>
+<div id="foo">This has <b>some HTML</b> inside it!</div>
+<script type="text/javascript">
+function hax() {
+    var foo = document.getElementById("foo");
+    console.log("trying");
+    foo.innerHTML = 'But now the HTML has changed!';
+}
+document.getElementById("clicky").addEventListener("mousedown", hax);
+</script>
+</body>
+</html>
diff --git a/Base/home/anon/www/welcome.html b/Base/home/anon/www/welcome.html
index 719d910ff4..af8dd8381d 100644
--- a/Base/home/anon/www/welcome.html
+++ b/Base/home/anon/www/welcome.html
@@ -23,6 +23,7 @@ h1 {
     <p>This is a very simple browser built on the LibWeb engine.</p>
     <p>Some small test pages:</p>
     <ul>
+        <li><a href="innerHTML.html">innerHTML property test</a></li>
         <li><a href="position-absolute-top-left.html">position: absolute; for top and left</a></li>
         <li><a href="demo.html">fun demo</a></li>
         <li><a href="raf.html">requestAnimationFrame test</a></li>
diff --git a/Libraries/LibWeb/Bindings/ElementWrapper.cpp b/Libraries/LibWeb/Bindings/ElementWrapper.cpp
new file mode 100644
index 0000000000..d392853973
--- /dev/null
+++ b/Libraries/LibWeb/Bindings/ElementWrapper.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/FlyString.h>
+#include <AK/Function.h>
+#include <LibJS/Runtime/PrimitiveString.h>
+#include <LibJS/Runtime/Value.h>
+#include <LibWeb/Bindings/ElementWrapper.h>
+#include <LibWeb/DOM/Element.h>
+
+namespace Web {
+namespace Bindings {
+
+ElementWrapper::ElementWrapper(Element& element)
+    : NodeWrapper(element)
+{
+    put_native_property(
+        "innerHTML",
+        [this](JS::Object*) {
+            return JS::js_string(heap(), node().inner_html());
+        },
+        [this](JS::Object*, JS::Value value) {
+            node().set_inner_html(value.to_string());
+        });
+}
+
+ElementWrapper::~ElementWrapper()
+{
+}
+
+Element& ElementWrapper::node()
+{
+    return static_cast<Element&>(NodeWrapper::node());
+}
+
+const Element& ElementWrapper::node() const
+{
+    return static_cast<const Element&>(NodeWrapper::node());
+}
+
+}
+}
diff --git a/Libraries/LibWeb/Bindings/ElementWrapper.h b/Libraries/LibWeb/Bindings/ElementWrapper.h
new file mode 100644
index 0000000000..d91c94ccf0
--- /dev/null
+++ b/Libraries/LibWeb/Bindings/ElementWrapper.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <LibWeb/Bindings/NodeWrapper.h>
+
+namespace Web {
+namespace Bindings {
+
+class ElementWrapper : public NodeWrapper {
+public:
+    explicit ElementWrapper(Element&);
+    virtual ~ElementWrapper() override;
+
+    Element& node();
+    const Element& node() const;
+
+private:
+    virtual const char* class_name() const override { return "ElementWrapper"; }
+};
+
+}
+}
diff --git a/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp b/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp
index 9c3895b0f0..99b8f9df10 100644
--- a/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.cpp
@@ -37,7 +37,7 @@ namespace Web {
 namespace Bindings {
 
 HTMLCanvasElementWrapper::HTMLCanvasElementWrapper(HTMLCanvasElement& element)
-    : NodeWrapper(element)
+    : ElementWrapper(element)
 {
     put_native_function("getContext", [this](JS::Object*, const Vector<JS::Value>& arguments) -> JS::Value {
         if (arguments.size() >= 1) {
diff --git a/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.h b/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.h
index ae46fa8914..d82342c668 100644
--- a/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.h
+++ b/Libraries/LibWeb/Bindings/HTMLCanvasElementWrapper.h
@@ -26,12 +26,12 @@
 
 #pragma once
 
-#include <LibWeb/Bindings/NodeWrapper.h>
+#include <LibWeb/Bindings/ElementWrapper.h>
 
 namespace Web {
 namespace Bindings {
 
-class HTMLCanvasElementWrapper : public NodeWrapper {
+class HTMLCanvasElementWrapper : public ElementWrapper {
 public:
     explicit HTMLCanvasElementWrapper(HTMLCanvasElement&);
     virtual ~HTMLCanvasElementWrapper() override;
diff --git a/Libraries/LibWeb/Bindings/NodeWrapper.cpp b/Libraries/LibWeb/Bindings/NodeWrapper.cpp
index badf650cc0..289a5c69f2 100644
--- a/Libraries/LibWeb/Bindings/NodeWrapper.cpp
+++ b/Libraries/LibWeb/Bindings/NodeWrapper.cpp
@@ -43,6 +43,8 @@ NodeWrapper* wrap(JS::Heap& heap, Node& node)
         return static_cast<NodeWrapper*>(wrap_impl(heap, to<Document>(node)));
     if (is<HTMLCanvasElement>(node))
         return static_cast<NodeWrapper*>(wrap_impl(heap, to<HTMLCanvasElement>(node)));
+    if (is<Element>(node))
+        return static_cast<NodeWrapper*>(wrap_impl(heap, to<Element>(node)));
     return static_cast<NodeWrapper*>(wrap_impl(heap, node));
 }
 
diff --git a/Libraries/LibWeb/DOM/Element.cpp b/Libraries/LibWeb/DOM/Element.cpp
index b7ebb004b1..3f5e93be41 100644
--- a/Libraries/LibWeb/DOM/Element.cpp
+++ b/Libraries/LibWeb/DOM/Element.cpp
@@ -24,11 +24,15 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <LibWeb/CSS/StyleResolver.h>
-#include <LibWeb/CSS/PropertyID.h>
+#include <AK/StringBuilder.h>
 #include <LibWeb/CSS/Length.h>
+#include <LibWeb/CSS/PropertyID.h>
+#include <LibWeb/CSS/StyleResolver.h>
 #include <LibWeb/DOM/Document.h>
+#include <LibWeb/DOM/DocumentFragment.h>
 #include <LibWeb/DOM/Element.h>
+#include <LibWeb/DOM/Text.h>
+#include <LibWeb/Dump.h>
 #include <LibWeb/Layout/LayoutBlock.h>
 #include <LibWeb/Layout/LayoutInline.h>
 #include <LibWeb/Layout/LayoutListItem.h>
@@ -36,6 +40,7 @@
 #include <LibWeb/Layout/LayoutTableCell.h>
 #include <LibWeb/Layout/LayoutTableRow.h>
 #include <LibWeb/Layout/LayoutTreeBuilder.h>
+#include <LibWeb/Parser/HTMLParser.h>
 
 namespace Web {
 
@@ -218,4 +223,47 @@ NonnullRefPtr<StyleProperties> Element::computed_style()
     return properties;
 }
 
+void Element::set_inner_html(StringView markup)
+{
+    auto fragment = parse_html_fragment(document(), markup);
+    remove_all_children();
+    if (!fragment)
+        return;
+    while (RefPtr<Node> child = fragment->first_child()) {
+        fragment->remove_child(*child);
+        append_child(*child);
+    }
+
+    set_needs_style_update(true);
+    document().schedule_style_update();
+    document().invalidate_layout();
+}
+
+String Element::inner_html() const
+{
+    StringBuilder builder;
+
+    Function<void(const Node&)> recurse = [&](auto& node) {
+        for (auto* child = node.first_child(); child; child = child->next_sibling()) {
+            if (child->is_element()) {
+                builder.append('<');
+                builder.append(to<Element>(*child).tag_name());
+                builder.append('>');
+
+                recurse(*child);
+
+                builder.append("</");
+                builder.append(to<Element>(*child).tag_name());
+                builder.append('>');
+            }
+            if (child->is_text()) {
+                builder.append(to<Text>(*child).data());
+            }
+        }
+    };
+    recurse(*this);
+
+    return builder.to_string();
+}
+
 }
diff --git a/Libraries/LibWeb/DOM/Element.h b/Libraries/LibWeb/DOM/Element.h
index b23ac2c454..f1602d4b07 100644
--- a/Libraries/LibWeb/DOM/Element.h
+++ b/Libraries/LibWeb/DOM/Element.h
@@ -55,6 +55,8 @@ private:
 
 class Element : public ParentNode {
 public:
+    using WrapperType = Bindings::ElementWrapper;
+
     Element(Document&, const FlyString& tag_name);
     virtual ~Element() override;
 
@@ -88,6 +90,9 @@ public:
     const StyleProperties* resolved_style() const { return m_resolved_style.ptr(); }
     NonnullRefPtr<StyleProperties> computed_style();
 
+    String inner_html() const;
+    void set_inner_html(StringView);
+
 private:
     RefPtr<LayoutNode> create_layout_node(const StyleProperties* parent_style) const override;
 
diff --git a/Libraries/LibWeb/Forward.h b/Libraries/LibWeb/Forward.h
index 623511e311..c94ddd4400 100644
--- a/Libraries/LibWeb/Forward.h
+++ b/Libraries/LibWeb/Forward.h
@@ -45,6 +45,7 @@ namespace Bindings {
 
 class CanvasRenderingContext2DWrapper;
 class DocumentWrapper;
+class ElementWrapper;
 class EventWrapper;
 class EventListenerWrapper;
 class EventTargetWrapper;
diff --git a/Libraries/LibWeb/Makefile b/Libraries/LibWeb/Makefile
index bc36ffeda1..5de6b61cd2 100644
--- a/Libraries/LibWeb/Makefile
+++ b/Libraries/LibWeb/Makefile
@@ -1,6 +1,7 @@
 LIBWEB_OBJS = \
     Bindings/CanvasRenderingContext2DWrapper.o \
     Bindings/DocumentWrapper.o \
+    Bindings/ElementWrapper.o \
     Bindings/EventWrapper.o \
     Bindings/EventListenerWrapper.o \
     Bindings/EventTargetWrapper.o \
