LibWeb: Move document loading into separate file

In upcoming navigables refactor new function that uses fetch
instead of ResourceLoader to load document content is going to be
introduced:
https://html.spec.whatwg.org/multipage/browsing-the-web.html#create-navigation-params-by-fetching

`parse_document()` need to be separated from FrameLoader to reuse
code responsible for parsing HTTP response into DOM document.

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -126,6 +126,7 @@ set(SOURCES
     DOM/DOMTokenList.cpp
     DOM/DOMTokenList.idl
     DOM/Document.cpp
+    DOM/DocumentLoading.cpp
     DOM/DocumentFragment.cpp
     DOM/DocumentLoadEventDelayer.cpp
     DOM/DocumentType.cpp

Userland/Libraries/LibWeb/DOM/DocumentLoading.cpp

@@ -0,0 +1,204 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2023, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Debug.h>
+#include <AK/LexicalPath.h>
+#include <LibGemini/Document.h>
+#include <LibGfx/ImageFormats/ImageDecoder.h>
+#include <LibMarkdown/Document.h>
+#include <LibTextCodec/Decoder.h>
+#include <LibWeb/DOM/Document.h>
+#include <LibWeb/DOM/DocumentLoading.h>
+#include <LibWeb/HTML/NavigationParams.h>
+#include <LibWeb/HTML/Parser/HTMLEncodingDetection.h>
+#include <LibWeb/HTML/Parser/HTMLParser.h>
+#include <LibWeb/Namespace.h>
+#include <LibWeb/Platform/ImageCodecPlugin.h>
+#include <LibWeb/XML/XMLDocumentBuilder.h>
+
+namespace Web {
+
+static bool build_markdown_document(DOM::Document& document, ByteBuffer const& data)
+{
+    auto markdown_document = Markdown::Document::parse(data);
+    if (!markdown_document)
+        return false;
+
+    auto extra_head_contents = R"~~~(
+<style>
+    .zoomable {
+        cursor: zoom-in;
+        max-width: 100%;
+    }
+    .zoomable.zoomed-in {
+        cursor: zoom-out;
+        max-width: none;
+    }
+</style>
+<script>
+    function imageClickEventListener(event) {
+        let image = event.target;
+        if (image.classList.contains("zoomable")) {
+            image.classList.toggle("zoomed-in");
+        }
+    }
+    function processImages() {
+        let images = document.querySelectorAll("img");
+        let windowWidth = window.innerWidth;
+        images.forEach((image) => {
+            if (image.naturalWidth > windowWidth) {
+                image.classList.add("zoomable");
+            } else {
+                image.classList.remove("zoomable");
+                image.classList.remove("zoomed-in");
+            }
+
+            image.addEventListener("click", imageClickEventListener);
+        });
+    }
+
+    document.addEventListener("load", () => {
+        processImages();
+    });
+
+    window.addEventListener("resize", () => {
+        processImages();
+    });
+</script>
+)~~~"sv;
+
+    auto parser = HTML::HTMLParser::create(document, markdown_document->render_to_html(extra_head_contents), "utf-8");
+    parser->run(document.url());
+    return true;
+}
+
+static bool build_text_document(DOM::Document& document, ByteBuffer const& data)
+{
+    auto html_element = DOM::create_element(document, HTML::TagNames::html, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(document.append_child(html_element));
+
+    auto head_element = DOM::create_element(document, HTML::TagNames::head, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(html_element->append_child(head_element));
+    auto title_element = DOM::create_element(document, HTML::TagNames::title, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(head_element->append_child(title_element));
+
+    auto title_text = document.create_text_node(document.url().basename());
+    MUST(title_element->append_child(title_text));
+
+    auto body_element = DOM::create_element(document, HTML::TagNames::body, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(html_element->append_child(body_element));
+
+    auto pre_element = DOM::create_element(document, HTML::TagNames::pre, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(body_element->append_child(pre_element));
+
+    MUST(pre_element->append_child(document.create_text_node(DeprecatedString::copy(data))));
+    return true;
+}
+
+static bool build_image_document(DOM::Document& document, ByteBuffer const& data)
+{
+    auto image = Platform::ImageCodecPlugin::the().decode_image(data);
+    if (!image.has_value() || image->frames.is_empty())
+        return false;
+    auto const& frame = image->frames[0];
+    auto const& bitmap = frame.bitmap;
+    if (!bitmap)
+        return false;
+
+    auto html_element = DOM::create_element(document, HTML::TagNames::html, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(document.append_child(html_element));
+
+    auto head_element = DOM::create_element(document, HTML::TagNames::head, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(html_element->append_child(head_element));
+    auto title_element = DOM::create_element(document, HTML::TagNames::title, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(head_element->append_child(title_element));
+
+    auto basename = LexicalPath::basename(document.url().serialize_path());
+    auto title_text = document.heap().allocate<DOM::Text>(document.realm(), document, DeprecatedString::formatted("{} [{}x{}]", basename, bitmap->width(), bitmap->height())).release_allocated_value_but_fixme_should_propagate_errors();
+    MUST(title_element->append_child(*title_text));
+
+    auto body_element = DOM::create_element(document, HTML::TagNames::body, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(html_element->append_child(body_element));
+
+    auto image_element = DOM::create_element(document, HTML::TagNames::img, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(image_element->set_attribute(HTML::AttributeNames::src, document.url().to_deprecated_string()));
+    MUST(body_element->append_child(image_element));
+
+    return true;
+}
+
+static bool build_gemini_document(DOM::Document& document, ByteBuffer const& data)
+{
+    StringView gemini_data { data };
+    auto gemini_document = Gemini::Document::parse(gemini_data, document.url());
+    DeprecatedString html_data = gemini_document->render_to_html();
+
+    dbgln_if(GEMINI_DEBUG, "Gemini data:\n\"\"\"{}\"\"\"", gemini_data);
+    dbgln_if(GEMINI_DEBUG, "Converted to HTML:\n\"\"\"{}\"\"\"", html_data);
+
+    auto parser = HTML::HTMLParser::create(document, html_data, "utf-8");
+    parser->run(document.url());
+    return true;
+}
+
+static bool build_xml_document(DOM::Document& document, ByteBuffer const& data)
+{
+    auto encoding = HTML::run_encoding_sniffing_algorithm(document, data);
+    auto decoder = TextCodec::decoder_for(encoding);
+    VERIFY(decoder.has_value());
+    auto source = decoder->to_utf8(data).release_value_but_fixme_should_propagate_errors();
+    XML::Parser parser(source, { .resolve_external_resource = resolve_xml_resource });
+    XMLDocumentBuilder builder { document };
+    auto result = parser.parse_with_listener(builder);
+    return !result.is_error() && !builder.has_error();
+}
+
+static bool build_video_document(DOM::Document& document)
+{
+    auto html_element = DOM::create_element(document, HTML::TagNames::html, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(document.append_child(html_element));
+
+    auto head_element = DOM::create_element(document, HTML::TagNames::head, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(html_element->append_child(head_element));
+
+    auto body_element = DOM::create_element(document, HTML::TagNames::body, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(html_element->append_child(body_element));
+
+    auto video_element = DOM::create_element(document, HTML::TagNames::video, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
+    MUST(video_element->set_attribute(HTML::AttributeNames::src, document.url().to_deprecated_string()));
+    MUST(video_element->set_attribute(HTML::AttributeNames::autoplay, DeprecatedString::empty()));
+    MUST(video_element->set_attribute(HTML::AttributeNames::controls, DeprecatedString::empty()));
+    MUST(body_element->append_child(video_element));
+
+    return true;
+}
+
+bool parse_document(DOM::Document& document, ByteBuffer const& data)
+{
+    auto& mime_type = document.content_type();
+    if (mime_type == "text/html" || mime_type == "image/svg+xml") {
+        auto parser = HTML::HTMLParser::create_with_uncertain_encoding(document, data);
+        parser->run(document.url());
+        return true;
+    }
+    if (mime_type.ends_with("+xml"sv) || mime_type.is_one_of("text/xml", "application/xml"))
+        return build_xml_document(document, data);
+    if (mime_type.starts_with("image/"sv))
+        return build_image_document(document, data);
+    if (mime_type.starts_with("video/"sv))
+        return build_video_document(document);
+    if (mime_type == "text/plain" || mime_type == "application/json")
+        return build_text_document(document, data);
+    if (mime_type == "text/markdown")
+        return build_markdown_document(document, data);
+    if (mime_type == "text/gemini")
+        return build_gemini_document(document, data);
+
+    return false;
+}
+
+}

Userland/Libraries/LibWeb/DOM/DocumentLoading.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2023, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/DOM/Document.h>
+
+namespace Web {
+
+bool parse_document(DOM::Document& document, ByteBuffer const& data);
+
+}

Userland/Libraries/LibWeb/Loader/FrameLoader.cpp

@@ -8,18 +8,12 @@
 #include <AK/JsonArray.h>
 #include <AK/LexicalPath.h>
 #include <AK/SourceGenerator.h>
-#include <LibGemini/Document.h>
-#include <LibGfx/ImageFormats/ImageDecoder.h>
-#include <LibMarkdown/Document.h>
-#include <LibTextCodec/Decoder.h>
 #include <LibWeb/Bindings/MainThreadVM.h>
 #include <LibWeb/DOM/Document.h>
+#include <LibWeb/DOM/DocumentLoading.h>
 #include <LibWeb/DOM/ElementFactory.h>
 #include <LibWeb/DOM/Text.h>
-#include <LibWeb/HTML/BrowsingContext.h>
-#include <LibWeb/HTML/HTMLIFrameElement.h>
 #include <LibWeb/HTML/NavigationParams.h>
-#include <LibWeb/HTML/Parser/HTMLEncodingDetection.h>
 #include <LibWeb/HTML/Parser/HTMLParser.h>
 #include <LibWeb/Loader/FrameLoader.h>
 #include <LibWeb/Loader/ResourceLoader.h>
@@ -49,185 +43,6 @@ FrameLoader::FrameLoader(HTML::BrowsingContext& browsing_context)
 
 FrameLoader::~FrameLoader() = default;
 
-static bool build_markdown_document(DOM::Document& document, ByteBuffer const& data)
-{
-    auto markdown_document = Markdown::Document::parse(data);
-    if (!markdown_document)
-        return false;
-
-    auto extra_head_contents = R"~~~(
-<style>
-    .zoomable {
-        cursor: zoom-in;
-        max-width: 100%;
-    }
-    .zoomable.zoomed-in {
-        cursor: zoom-out;
-        max-width: none;
-    }
-</style>
-<script>
-    function imageClickEventListener(event) {
-        let image = event.target;
-        if (image.classList.contains("zoomable")) {
-            image.classList.toggle("zoomed-in");
-        }
-    }
-    function processImages() {
-        let images = document.querySelectorAll("img");
-        let windowWidth = window.innerWidth;
-        images.forEach((image) => {
-            if (image.naturalWidth > windowWidth) {
-                image.classList.add("zoomable");
-            } else {
-                image.classList.remove("zoomable");
-                image.classList.remove("zoomed-in");
-            }
-
-            image.addEventListener("click", imageClickEventListener);
-        });
-    }
-
-    document.addEventListener("load", () => {
-        processImages();
-    });
-
-    window.addEventListener("resize", () => {
-        processImages();
-    });
-</script>
-)~~~"sv;
-
-    auto parser = HTML::HTMLParser::create(document, markdown_document->render_to_html(extra_head_contents), "utf-8");
-    parser->run(document.url());
-    return true;
-}
-
-static bool build_text_document(DOM::Document& document, ByteBuffer const& data)
-{
-    auto html_element = DOM::create_element(document, HTML::TagNames::html, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(document.append_child(html_element));
-
-    auto head_element = DOM::create_element(document, HTML::TagNames::head, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(html_element->append_child(head_element));
-    auto title_element = DOM::create_element(document, HTML::TagNames::title, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(head_element->append_child(title_element));
-
-    auto title_text = document.create_text_node(document.url().basename());
-    MUST(title_element->append_child(title_text));
-
-    auto body_element = DOM::create_element(document, HTML::TagNames::body, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(html_element->append_child(body_element));
-
-    auto pre_element = DOM::create_element(document, HTML::TagNames::pre, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(body_element->append_child(pre_element));
-
-    MUST(pre_element->append_child(document.create_text_node(DeprecatedString::copy(data))));
-    return true;
-}
-
-static bool build_image_document(DOM::Document& document, ByteBuffer const& data)
-{
-    auto image = Platform::ImageCodecPlugin::the().decode_image(data);
-    if (!image.has_value() || image->frames.is_empty())
-        return false;
-    auto const& frame = image->frames[0];
-    auto const& bitmap = frame.bitmap;
-    if (!bitmap)
-        return false;
-
-    auto html_element = DOM::create_element(document, HTML::TagNames::html, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(document.append_child(html_element));
-
-    auto head_element = DOM::create_element(document, HTML::TagNames::head, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(html_element->append_child(head_element));
-    auto title_element = DOM::create_element(document, HTML::TagNames::title, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(head_element->append_child(title_element));
-
-    auto basename = LexicalPath::basename(document.url().serialize_path());
-    auto title_text = document.heap().allocate<DOM::Text>(document.realm(), document, DeprecatedString::formatted("{} [{}x{}]", basename, bitmap->width(), bitmap->height())).release_allocated_value_but_fixme_should_propagate_errors();
-    MUST(title_element->append_child(*title_text));
-
-    auto body_element = DOM::create_element(document, HTML::TagNames::body, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(html_element->append_child(body_element));
-
-    auto image_element = DOM::create_element(document, HTML::TagNames::img, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(image_element->set_attribute(HTML::AttributeNames::src, document.url().to_deprecated_string()));
-    MUST(body_element->append_child(image_element));
-
-    return true;
-}
-
-static bool build_gemini_document(DOM::Document& document, ByteBuffer const& data)
-{
-    StringView gemini_data { data };
-    auto gemini_document = Gemini::Document::parse(gemini_data, document.url());
-    DeprecatedString html_data = gemini_document->render_to_html();
-
-    dbgln_if(GEMINI_DEBUG, "Gemini data:\n\"\"\"{}\"\"\"", gemini_data);
-    dbgln_if(GEMINI_DEBUG, "Converted to HTML:\n\"\"\"{}\"\"\"", html_data);
-
-    auto parser = HTML::HTMLParser::create(document, html_data, "utf-8");
-    parser->run(document.url());
-    return true;
-}
-
-static bool build_xml_document(DOM::Document& document, ByteBuffer const& data)
-{
-    auto encoding = HTML::run_encoding_sniffing_algorithm(document, data);
-    auto decoder = TextCodec::decoder_for(encoding);
-    VERIFY(decoder.has_value());
-    auto source = decoder->to_utf8(data).release_value_but_fixme_should_propagate_errors();
-    XML::Parser parser(source, { .resolve_external_resource = resolve_xml_resource });
-    XMLDocumentBuilder builder { document };
-    auto result = parser.parse_with_listener(builder);
-    return !result.is_error() && !builder.has_error();
-}
-
-static bool build_video_document(DOM::Document& document)
-{
-    auto html_element = DOM::create_element(document, HTML::TagNames::html, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(document.append_child(html_element));
-
-    auto head_element = DOM::create_element(document, HTML::TagNames::head, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(html_element->append_child(head_element));
-
-    auto body_element = DOM::create_element(document, HTML::TagNames::body, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(html_element->append_child(body_element));
-
-    auto video_element = DOM::create_element(document, HTML::TagNames::video, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
-    MUST(video_element->set_attribute(HTML::AttributeNames::src, document.url().to_deprecated_string()));
-    MUST(video_element->set_attribute(HTML::AttributeNames::autoplay, DeprecatedString::empty()));
-    MUST(video_element->set_attribute(HTML::AttributeNames::controls, DeprecatedString::empty()));
-    MUST(body_element->append_child(video_element));
-
-    return true;
-}
-
-bool FrameLoader::parse_document(DOM::Document& document, ByteBuffer const& data)
-{
-    auto& mime_type = document.content_type();
-    if (mime_type == "text/html" || mime_type == "image/svg+xml") {
-        auto parser = HTML::HTMLParser::create_with_uncertain_encoding(document, data);
-        parser->run(document.url());
-        return true;
-    }
-    if (mime_type.ends_with("+xml"sv) || mime_type.is_one_of("text/xml", "application/xml"))
-        return build_xml_document(document, data);
-    if (mime_type.starts_with("image/"sv))
-        return build_image_document(document, data);
-    if (mime_type.starts_with("video/"sv))
-        return build_video_document(document);
-    if (mime_type == "text/plain" || mime_type == "application/json")
-        return build_text_document(document, data);
-    if (mime_type == "text/markdown")
-        return build_markdown_document(document, data);
-    if (mime_type == "text/gemini")
-        return build_gemini_document(document, data);
-
-    return false;
-}
-
 bool FrameLoader::load(LoadRequest& request, Type type)
 {
     if (!request.is_valid()) {

Userland/Libraries/LibWeb/Loader/FrameLoader.h

@@ -45,7 +45,6 @@ private:
 
     void load_error_page(const AK::URL& failed_url, DeprecatedString const& error_message);
     void load_favicon(RefPtr<Gfx::Bitmap> bitmap = nullptr);
-    bool parse_document(DOM::Document&, ByteBuffer const& data);
 
     JS::NonnullGCPtr<HTML::BrowsingContext> m_browsing_context;
     size_t m_redirects_count { 0 };