LibWeb: Implement `<meta http-equiv="Refresh">`

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Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -9,6 +9,7 @@
 
 #include <AK/CharacterTypes.h>
 #include <AK/Debug.h>
+#include <AK/GenericLexer.h>
 #include <AK/StringBuilder.h>
 #include <AK/Utf8View.h>
 #include <LibCore/Timer.h>
@@ -77,6 +78,7 @@
 #include <LibWeb/HTML/Window.h>
 #include <LibWeb/HTML/WindowProxy.h>
 #include <LibWeb/HighResolutionTime/TimeOrigin.h>
+#include <LibWeb/Infra/CharacterTypes.h>
 #include <LibWeb/Infra/Strings.h>
 #include <LibWeb/IntersectionObserver/IntersectionObserver.h>
 #include <LibWeb/Layout/BlockFormattingContext.h>
@@ -1756,6 +1758,10 @@ void Document::completely_finish_loading()
     // 2. Set document's completely loaded time to the current time.
     m_completely_loaded_time = AK::UnixDateTime::now();
 
+    // NOTE: See the end of shared_declarative_refresh_steps.
+    if (m_active_refresh_timer)
+        m_active_refresh_timer->start();
+
     // 3. Let container be document's browsing context's container.
     auto container = JS::make_handle(browsing_context()->container());
 
@@ -3049,4 +3055,162 @@ void Document::start_intersection_observing_a_lazy_loading_element(Element& elem
     m_lazy_load_intersection_observer->observe(element);
 }
 
+// https://html.spec.whatwg.org/multipage/semantics.html#shared-declarative-refresh-steps
+void Document::shared_declarative_refresh_steps(StringView input, JS::GCPtr<HTML::HTMLMetaElement const> meta_element)
+{
+    // 1. If document's will declaratively refresh is true, then return.
+    if (m_will_declaratively_refresh)
+        return;
+
+    // 2. Let position point at the first code point of input.
+    GenericLexer lexer(input);
+
+    // 3. Skip ASCII whitespace within input given position.
+    lexer.ignore_while(Infra::is_ascii_whitespace);
+
+    // 4. Let time be 0.
+    u32 time = 0;
+
+    // 5. Collect a sequence of code points that are ASCII digits from input given position, and let the result be timeString.
+    auto time_string = lexer.consume_while(is_ascii_digit);
+
+    // 6. If timeString is the empty string, then:
+    if (time_string.is_empty()) {
+        // 1. If the code point in input pointed to by position is not U+002E (.), then return.
+        if (lexer.peek() != '.')
+            return;
+    }
+
+    // 7. Otherwise, set time to the result of parsing timeString using the rules for parsing non-negative integers.
+    // FIXME: Not sure if this exactly matches the spec's "rules for parsing non-negative integers".
+    auto maybe_time = time_string.to_uint<u32>();
+
+    // FIXME: Since we only collected ASCII digits, this can only fail because of overflow. What do we do when that happens? For now, default to 0.
+    if (maybe_time.has_value() && maybe_time.value() < NumericLimits<int>::max() && !Checked<int>::multiplication_would_overflow(static_cast<int>(maybe_time.value()), 1000)) {
+        time = maybe_time.value();
+    }
+
+    // 8. Collect a sequence of code points that are ASCII digits and U+002E FULL STOP characters (.) from input given
+    //    position. Ignore any collected characters.
+    lexer.ignore_while([](auto c) {
+        return is_ascii_digit(c) || c == '.';
+    });
+
+    // 9. Let urlRecord be document's URL.
+    auto url_record = url();
+
+    // 10. If position is not past the end of input, then:
+    if (!lexer.is_eof()) {
+        // 1. If the code point in input pointed to by position is not U+003B (;), U+002C (,), or ASCII whitespace, then return.
+        if (lexer.peek() != ';' && lexer.peek() != ',' && !Infra::is_ascii_whitespace(lexer.peek()))
+            return;
+
+        // 2. Skip ASCII whitespace within input given position.
+        lexer.ignore_while(Infra::is_ascii_whitespace);
+
+        // 3. If the code point in input pointed to by position is U+003B (;) or U+002C (,), then advance position to the next code point.
+        if (lexer.peek() == ';' || lexer.peek() == ',')
+            lexer.ignore(1);
+
+        // 4. Skip ASCII whitespace within input given position.
+        lexer.ignore_while(Infra::is_ascii_whitespace);
+    }
+
+    // 11. If position is not past the end of input, then:
+    if (!lexer.is_eof()) {
+        // 1. Let urlString be the substring of input from the code point at position to the end of the string.
+        auto url_string = lexer.remaining();
+
+        // 2. If the code point in input pointed to by position is U+0055 (U) or U+0075 (u), then advance position to the next code point. Otherwise, jump to the step labeled skip quotes.
+        if (lexer.peek() == 'U' || lexer.peek() == 'u')
+            lexer.ignore(1);
+        else
+            goto skip_quotes;
+
+        // 3. If the code point in input pointed to by position is U+0052 (R) or U+0072 (r), then advance position to the next code point. Otherwise, jump to the step labeled parse.
+        if (lexer.peek() == 'R' || lexer.peek() == 'r')
+            lexer.ignore(1);
+        else
+            goto parse;
+
+        // 4. If the code point in input pointed to by position is U+004C (L) or U+006C (l), then advance position to the next code point. Otherwise, jump to the step labeled parse.
+        if (lexer.peek() == 'L' || lexer.peek() == 'l')
+            lexer.ignore(1);
+        else
+            goto parse;
+
+        // 5. Skip ASCII whitespace within input given position.
+        lexer.ignore_while(Infra::is_ascii_whitespace);
+
+        // 6. If the code point in input pointed to by position is U+003D (=), then advance position to the next code point. Otherwise, jump to the step labeled parse.
+        if (lexer.peek() == '=')
+            lexer.ignore(1);
+        else
+            goto parse;
+
+        // 7. Skip ASCII whitespace within input given position.
+        lexer.ignore_while(Infra::is_ascii_whitespace);
+
+    skip_quotes : {
+        // 8. Skip quotes: If the code point in input pointed to by position is U+0027 (') or U+0022 ("), then let
+        //    quote be that code point, and advance position to the next code point. Otherwise, let quote be the empty
+        //    string.
+        Optional<char> quote;
+        if (lexer.peek() == '\'' || lexer.peek() == '"')
+            quote = lexer.consume();
+
+        // 9. Set urlString to the substring of input from the code point at position to the end of the string.
+        // 10. If quote is not the empty string, and there is a code point in urlString equal to quote, then truncate
+        //     urlString at that code point, so that it and all subsequent code points are removed.
+        url_string = lexer.consume_while([&quote](auto c) {
+            return !quote.has_value() || c != quote.value();
+        });
+    }
+
+    parse:
+        // 11. Parse: Parse urlString relative to document. If that fails, return. Otherwise, set urlRecord to the
+        //     resulting URL record.
+        auto maybe_url_record = parse_url(url_string);
+        if (!maybe_url_record.is_valid())
+            return;
+
+        url_record = maybe_url_record;
+    }
+
+    // 12. Set document's will declaratively refresh to true.
+    m_will_declaratively_refresh = true;
+
+    // 13. Perform one or more of the following steps:
+    // - After the refresh has come due (as defined below), if the user has not canceled the redirect and, if meta is
+    //   given, document's active sandboxing flag set does not have the sandboxed automatic features browsing context
+    //   flag set, then navigate document's node navigable to urlRecord using document, with historyHandling set to
+    //   "replace".
+    m_active_refresh_timer = Core::Timer::create_single_shot(time * 1000, [this, has_meta_element = !!meta_element, url_record = move(url_record)]() {
+        if (has_meta_element && active_sandboxing_flag_set().flags & HTML::SandboxingFlagSet::SandboxedAutomaticFeatures)
+            return;
+
+        // FIXME: Use navigables when they're used for all navigation (otherwise, navigable() would be null in some cases)
+        VERIFY(browsing_context());
+        auto request = Fetch::Infrastructure::Request::create(vm());
+        request->set_url(url_record);
+        MUST(browsing_context()->navigate(request, *browsing_context(), false, HTML::HistoryHandlingBehavior::Replace));
+    }).release_value_but_fixme_should_propagate_errors();
+
+    // For the purposes of the previous paragraph, a refresh is said to have come due as soon as the later of the
+    // following two conditions occurs:
+
+    // - At least time seconds have elapsed since document's completely loaded time, adjusted to take into
+    //   account user or user agent preferences.
+    // m_active_refresh_timer is started in completely_finished_loading after setting the completely loaded time.
+
+    // - If meta is given, at least time seconds have elapsed since meta was inserted into the document document,
+    // adjusted to take into account user or user agent preferences.
+    // NOTE: This is only done if completely loaded time has a value because shared_declarative_refresh_steps is called
+    // by HTMLMetaElement::inserted and if the document hasn't finished loading when the meta element was inserted,
+    // then the document completely finishing loading will _always_ come after inserting the meta element.
+    if (meta_element && m_completely_loaded_time.has_value()) {
+        m_active_refresh_timer->start();
+    }
+}
+
 }

Userland/Libraries/LibWeb/DOM/Document.h

@@ -495,6 +495,8 @@ public:
 
     void start_intersection_observing_a_lazy_loading_element(Element& element);
 
+    void shared_declarative_refresh_steps(StringView input, JS::GCPtr<HTML::HTMLMetaElement const> meta_element = nullptr);
+
 protected:
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
@@ -676,6 +678,12 @@ private:
     // https://html.spec.whatwg.org/multipage/urls-and-fetching.html#lazy-load-intersection-observer
     // Each Document has a lazy load intersection observer, initially set to null but can be set to an IntersectionObserver instance.
     JS::GCPtr<IntersectionObserver::IntersectionObserver> m_lazy_load_intersection_observer;
+
+    // https://html.spec.whatwg.org/multipage/semantics.html#will-declaratively-refresh
+    // A Document object has an associated will declaratively refresh (a boolean). It is initially false.
+    bool m_will_declaratively_refresh { false };
+
+    RefPtr<Core::Timer> m_active_refresh_timer;
 };
 
 template<>

Userland/Libraries/LibWeb/HTML/HTMLMetaElement.cpp

@@ -1,10 +1,12 @@
 /*
  * Copyright (c) 2020, the SerenityOS developers.
+ * Copyright (c) 2023, Luke Wilde <lukew@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/DOM/Document.h>
 #include <LibWeb/HTML/HTMLMetaElement.h>
 
 namespace Web::HTML {
@@ -24,4 +26,50 @@ JS::ThrowCompletionOr<void> HTMLMetaElement::initialize(JS::Realm& realm)
     return {};
 }
 
+Optional<HTMLMetaElement::HttpEquivAttributeState> HTMLMetaElement::http_equiv_state() const
+{
+    auto value = attribute(HTML::AttributeNames::http_equiv);
+
+#define __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE(keyword, state) \
+    if (value.equals_ignoring_ascii_case(#keyword##sv))            \
+        return HTMLMetaElement::HttpEquivAttributeState::state;
+    ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTES
+#undef __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE
+
+    return OptionalNone {};
+}
+
+void HTMLMetaElement::inserted()
+{
+    Base::inserted();
+
+    // https://html.spec.whatwg.org/multipage/semantics.html#pragma-directives
+    // When a meta element is inserted into the document, if its http-equiv attribute is present and represents one of
+    // the above states, then the user agent must run the algorithm appropriate for that state, as described in the
+    // following list:
+    auto http_equiv = http_equiv_state();
+    if (http_equiv.has_value()) {
+        switch (http_equiv.value()) {
+        case HttpEquivAttributeState::Refresh: {
+            // https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-refresh
+            // 1. If the meta element has no content attribute, or if that attribute's value is the empty string, then return.
+            // 2. Let input be the value of the element's content attribute.
+            if (!has_attribute(AttributeNames::content))
+                break;
+
+            auto input = attribute(AttributeNames::content);
+            if (input.is_empty())
+                break;
+
+            // 3. Run the shared declarative refresh steps with the meta element's node document, input, and the meta element.
+            document().shared_declarative_refresh_steps(input, this);
+            break;
+        }
+        default:
+            dbgln("FIXME: Implement '{}' http-equiv state", attribute(AttributeNames::http_equiv));
+            break;
+        }
+    }
+}
+
 }

Userland/Libraries/LibWeb/HTML/HTMLMetaElement.h

@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2020, the SerenityOS developers.
+ * Copyright (c) 2023, Luke Wilde <lukew@serenityos.org>
  *
  * SPDX-License-Identifier: BSD-2-Clause
  */
@@ -10,16 +11,37 @@
 
 namespace Web::HTML {
 
+// https://html.spec.whatwg.org/multipage/semantics.html#pragma-directives
+#define ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTES                                   \
+    __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE("content-language", ContentLanguage) \
+    __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE("content-type", EncodingDeclaration) \
+    __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE("default-style", DefaultStyle)       \
+    __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE(refresh, Refresh)                    \
+    __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE("set-cookie", SetCookie)             \
+    __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE("x-ua-compatible", XUACompatible)    \
+    __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE("content-security-policy", ContentSecurityPolicy)
+
 class HTMLMetaElement final : public HTMLElement {
     WEB_PLATFORM_OBJECT(HTMLMetaElement, HTMLElement);
 
 public:
     virtual ~HTMLMetaElement() override;
 
+    enum class HttpEquivAttributeState {
+#define __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE(_, state) state,
+        ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTES
+#undef __ENUMERATE_HTML_META_HTTP_EQUIV_ATTRIBUTE
+    };
+
+    Optional<HttpEquivAttributeState> http_equiv_state() const;
+
 private:
     HTMLMetaElement(DOM::Document&, DOM::QualifiedName);
 
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
+
+    // ^DOM::Element
+    virtual void inserted() override;
 };
 
 }