script/dom/html/
htmllinkelement.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5use std::borrow::{Borrow, ToOwned};
6use std::cell::Cell;
7use std::default::Default;
8
9use base::generic_channel::GenericSharedMemory;
10use dom_struct::dom_struct;
11use html5ever::{LocalName, Prefix, local_name};
12use js::context::JSContext;
13use js::rust::HandleObject;
14use net_traits::image_cache::{
15    Image, ImageCache, ImageCacheResponseCallback, ImageCacheResult, ImageLoadListener,
16    ImageOrMetadataAvailable, ImageResponse, PendingImageId,
17};
18use net_traits::request::{Destination, Initiator, RequestBuilder, RequestId};
19use net_traits::{
20    FetchMetadata, FetchResponseMsg, NetworkError, ReferrerPolicy, ResourceFetchTiming,
21};
22use pixels::PixelFormat;
23use script_bindings::root::Dom;
24use servo_arc::Arc;
25use servo_url::ServoUrl;
26use style::attr::AttrValue;
27use style::media_queries::MediaList as StyleMediaList;
28use style::stylesheets::Stylesheet;
29use stylo_atoms::Atom;
30use webrender_api::units::DeviceIntSize;
31
32use crate::dom::attr::Attr;
33use crate::dom::bindings::cell::DomRefCell;
34use crate::dom::bindings::codegen::Bindings::DOMTokenListBinding::DOMTokenList_Binding::DOMTokenListMethods;
35use crate::dom::bindings::codegen::Bindings::HTMLLinkElementBinding::HTMLLinkElementMethods;
36use crate::dom::bindings::inheritance::Castable;
37use crate::dom::bindings::refcounted::Trusted;
38use crate::dom::bindings::reflector::DomGlobal;
39use crate::dom::bindings::root::{DomRoot, MutNullableDom};
40use crate::dom::bindings::str::{DOMString, USVString};
41use crate::dom::csp::{GlobalCspReporting, Violation};
42use crate::dom::css::cssstylesheet::CSSStyleSheet;
43use crate::dom::css::stylesheet::StyleSheet as DOMStyleSheet;
44use crate::dom::document::Document;
45use crate::dom::documentorshadowroot::StylesheetSource;
46use crate::dom::domtokenlist::DOMTokenList;
47use crate::dom::element::{
48    AttributeMutation, Element, ElementCreator, cors_setting_for_element,
49    referrer_policy_for_element, reflect_cross_origin_attribute, reflect_referrer_policy_attribute,
50    set_cross_origin_attribute,
51};
52use crate::dom::html::htmlelement::HTMLElement;
53use crate::dom::medialist::MediaList;
54use crate::dom::node::{BindContext, Node, NodeTraits, UnbindContext};
55use crate::dom::performance::performanceresourcetiming::InitiatorType;
56use crate::dom::processingoptions::{
57    LinkFetchContext, LinkFetchContextType, LinkProcessingOptions,
58};
59use crate::dom::types::{EventTarget, GlobalScope};
60use crate::dom::virtualmethods::VirtualMethods;
61use crate::links::LinkRelations;
62use crate::network_listener::{FetchResponseListener, ResourceTimingListener, submit_timing};
63use crate::script_runtime::CanGc;
64use crate::stylesheet_loader::{ElementStylesheetLoader, StylesheetContextSource, StylesheetOwner};
65
66#[derive(Clone, Copy, JSTraceable, MallocSizeOf, PartialEq)]
67pub(crate) struct RequestGenerationId(u32);
68
69impl RequestGenerationId {
70    fn increment(self) -> RequestGenerationId {
71        RequestGenerationId(self.0 + 1)
72    }
73}
74
75#[dom_struct]
76pub(crate) struct HTMLLinkElement {
77    htmlelement: HTMLElement,
78    /// The relations as specified by the "rel" attribute
79    rel_list: MutNullableDom<DOMTokenList>,
80
81    /// The link relations as they are used in practice.
82    ///
83    /// The reason this is separate from [HTMLLinkElement::rel_list] is that
84    /// a literal list is a bit unwieldy and that there are corner cases to consider
85    /// (Like `rev="made"` implying an author relationship that is not represented in rel_list)
86    #[no_trace]
87    relations: Cell<LinkRelations>,
88
89    #[conditional_malloc_size_of]
90    #[no_trace]
91    stylesheet: DomRefCell<Option<Arc<Stylesheet>>>,
92    cssom_stylesheet: MutNullableDom<CSSStyleSheet>,
93
94    /// <https://html.spec.whatwg.org/multipage/#a-style-sheet-that-is-blocking-scripts>
95    parser_inserted: Cell<bool>,
96    /// The number of loads that this link element has triggered (could be more
97    /// than one because of imports) and have not yet finished.
98    pending_loads: Cell<u32>,
99    /// Whether any of the loads have failed.
100    any_failed_load: Cell<bool>,
101    /// A monotonically increasing counter that keeps track of which stylesheet to apply.
102    request_generation_id: Cell<RequestGenerationId>,
103    /// <https://html.spec.whatwg.org/multipage/#explicitly-enabled>
104    is_explicitly_enabled: Cell<bool>,
105    /// Whether the previous type matched with the destination
106    previous_type_matched: Cell<bool>,
107    /// Whether the previous media environment matched with the media query
108    previous_media_environment_matched: Cell<bool>,
109    /// Line number this element was created on
110    line_number: u64,
111    /// <https://html.spec.whatwg.org/multipage/#dom-link-blocking>
112    blocking: MutNullableDom<DOMTokenList>,
113}
114
115impl HTMLLinkElement {
116    fn new_inherited(
117        local_name: LocalName,
118        prefix: Option<Prefix>,
119        document: &Document,
120        creator: ElementCreator,
121    ) -> HTMLLinkElement {
122        HTMLLinkElement {
123            htmlelement: HTMLElement::new_inherited(local_name, prefix, document),
124            rel_list: Default::default(),
125            relations: Cell::new(LinkRelations::empty()),
126            parser_inserted: Cell::new(creator.is_parser_created()),
127            stylesheet: DomRefCell::new(None),
128            cssom_stylesheet: MutNullableDom::new(None),
129            pending_loads: Cell::new(0),
130            any_failed_load: Cell::new(false),
131            request_generation_id: Cell::new(RequestGenerationId(0)),
132            is_explicitly_enabled: Cell::new(false),
133            previous_type_matched: Cell::new(true),
134            previous_media_environment_matched: Cell::new(true),
135            line_number: creator.return_line_number(),
136            blocking: Default::default(),
137        }
138    }
139
140    pub(crate) fn new(
141        local_name: LocalName,
142        prefix: Option<Prefix>,
143        document: &Document,
144        proto: Option<HandleObject>,
145        creator: ElementCreator,
146        can_gc: CanGc,
147    ) -> DomRoot<HTMLLinkElement> {
148        Node::reflect_node_with_proto(
149            Box::new(HTMLLinkElement::new_inherited(
150                local_name, prefix, document, creator,
151            )),
152            document,
153            proto,
154            can_gc,
155        )
156    }
157
158    pub(crate) fn get_request_generation_id(&self) -> RequestGenerationId {
159        self.request_generation_id.get()
160    }
161
162    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
163    fn remove_stylesheet(&self) {
164        if let Some(stylesheet) = self.stylesheet.borrow_mut().take() {
165            let owner = self.stylesheet_list_owner();
166            owner.remove_stylesheet(
167                StylesheetSource::Element(Dom::from_ref(self.upcast())),
168                &stylesheet,
169            );
170            self.clean_stylesheet_ownership();
171            owner.invalidate_stylesheets();
172        }
173    }
174
175    // FIXME(emilio): These methods are duplicated with
176    // HTMLStyleElement::set_stylesheet.
177    #[cfg_attr(crown, expect(crown::unrooted_must_root))]
178    pub(crate) fn set_stylesheet(&self, new_stylesheet: Arc<Stylesheet>) {
179        let owner = self.stylesheet_list_owner();
180        if let Some(old_stylesheet) = self.stylesheet.borrow_mut().replace(new_stylesheet.clone()) {
181            owner.remove_stylesheet(
182                StylesheetSource::Element(Dom::from_ref(self.upcast())),
183                &old_stylesheet,
184            );
185        }
186        owner.add_owned_stylesheet(self.upcast(), new_stylesheet);
187    }
188
189    pub(crate) fn get_stylesheet(&self) -> Option<Arc<Stylesheet>> {
190        self.stylesheet.borrow().clone()
191    }
192
193    pub(crate) fn get_cssom_stylesheet(&self, can_gc: CanGc) -> Option<DomRoot<CSSStyleSheet>> {
194        self.get_stylesheet().map(|sheet| {
195            self.cssom_stylesheet.or_init(|| {
196                CSSStyleSheet::new(
197                    &self.owner_window(),
198                    Some(self.upcast::<Element>()),
199                    "text/css".into(),
200                    Some(self.Href().into()),
201                    None, // todo handle title
202                    sheet,
203                    None, // constructor_document
204                    can_gc,
205                )
206            })
207        })
208    }
209
210    pub(crate) fn is_alternate(&self) -> bool {
211        self.relations.get().contains(LinkRelations::ALTERNATE) &&
212            !self
213                .upcast::<Element>()
214                .get_string_attribute(&local_name!("title"))
215                .is_empty()
216    }
217
218    pub(crate) fn is_effectively_disabled(&self) -> bool {
219        (self.is_alternate() && !self.is_explicitly_enabled.get()) ||
220            self.upcast::<Element>()
221                .has_attribute(&local_name!("disabled"))
222    }
223
224    fn clean_stylesheet_ownership(&self) {
225        if let Some(cssom_stylesheet) = self.cssom_stylesheet.get() {
226            cssom_stylesheet.set_owner_node(None);
227        }
228        self.cssom_stylesheet.set(None);
229    }
230}
231
232fn get_attr(element: &Element, local_name: &LocalName) -> Option<String> {
233    let elem = element.get_attribute(local_name);
234    elem.map(|e| {
235        let value = e.value();
236        (**value).to_owned()
237    })
238}
239
240impl VirtualMethods for HTMLLinkElement {
241    fn super_type(&self) -> Option<&dyn VirtualMethods> {
242        Some(self.upcast::<HTMLElement>() as &dyn VirtualMethods)
243    }
244
245    fn attribute_mutated(&self, attr: &Attr, mutation: AttributeMutation, can_gc: CanGc) {
246        self.super_type()
247            .unwrap()
248            .attribute_mutated(attr, mutation, can_gc);
249
250        let local_name = attr.local_name();
251        let is_removal = mutation.is_removal();
252        if *local_name == local_name!("disabled") {
253            self.handle_disabled_attribute_change(is_removal);
254            return;
255        }
256        let node = self.upcast::<Node>();
257
258        if !node.is_connected() {
259            return;
260        }
261
262        // For stylesheets, we should only refetch when the actual attribute value
263        // has been changed.
264        if self.relations.get().contains(LinkRelations::STYLESHEET) {
265            if let AttributeMutation::Set(Some(previous_value), _) = mutation {
266                if **previous_value == **attr.value() {
267                    return;
268                }
269            }
270        }
271
272        match *local_name {
273            local_name!("rel") | local_name!("rev") => {
274                let previous_relations = self.relations.get();
275                self.relations
276                    .set(LinkRelations::for_element(self.upcast()));
277
278                // If relations haven't changed, we shouldn't do anything
279                if previous_relations == self.relations.get() {
280                    return;
281                }
282
283                // https://html.spec.whatwg.org/multipage/#link-type-stylesheet:fetch-and-process-the-linked-resource
284                // > When the external resource link is created on a link element that is already browsing-context connected.
285                if self.relations.get().contains(LinkRelations::STYLESHEET) {
286                    self.handle_stylesheet_url();
287                } else {
288                    self.remove_stylesheet();
289                }
290            },
291            local_name!("href") => {
292                // https://html.spec.whatwg.org/multipage/#attr-link-href
293                // > If both the href and imagesrcset attributes are absent, then the element does not define a link.
294                if is_removal {
295                    if self.relations.get().contains(LinkRelations::STYLESHEET) {
296                        self.remove_stylesheet();
297                    }
298                    return;
299                }
300                // https://html.spec.whatwg.org/multipage/#link-type-stylesheet:fetch-and-process-the-linked-resource
301                // > When the href attribute of the link element of an external resource link
302                // > that is already browsing-context connected is changed.
303                if self.relations.get().contains(LinkRelations::STYLESHEET) {
304                    self.handle_stylesheet_url();
305                }
306
307                if self.relations.get().contains(LinkRelations::ICON) {
308                    self.handle_favicon_url(&attr.value());
309                }
310
311                // https://html.spec.whatwg.org/multipage/#link-type-prefetch
312                // When the href attribute of the link element of an external resource link
313                // that is already browsing-context connected is changed.
314                if self.relations.get().contains(LinkRelations::PREFETCH) {
315                    self.fetch_and_process_prefetch_link(&attr.value());
316                }
317
318                // https://html.spec.whatwg.org/multipage/#link-type-preload
319                // When the href attribute of the link element of an external resource link
320                // that is already browsing-context connected is changed.
321                if self.relations.get().contains(LinkRelations::PRELOAD) {
322                    self.handle_preload_url();
323                }
324            },
325            local_name!("sizes") if self.relations.get().contains(LinkRelations::ICON) => {
326                self.handle_favicon_url(&attr.value());
327            },
328            local_name!("crossorigin") => {
329                // https://html.spec.whatwg.org/multipage/#link-type-prefetch
330                // When the crossorigin attribute of the link element of an external resource link
331                // that is already browsing-context connected is set, changed, or removed.
332                if self.relations.get().contains(LinkRelations::PREFETCH) {
333                    self.fetch_and_process_prefetch_link(&attr.value());
334                }
335
336                // https://html.spec.whatwg.org/multipage/#link-type-stylesheet
337                // When the crossorigin attribute of the link element of an external resource link
338                // that is already browsing-context connected is set, changed, or removed.
339                if self.relations.get().contains(LinkRelations::STYLESHEET) {
340                    self.handle_stylesheet_url();
341                }
342            },
343            local_name!("as") => {
344                // https://html.spec.whatwg.org/multipage/#link-type-preload
345                // When the as attribute of the link element of an external resource link
346                // that is already browsing-context connected is changed.
347                if self.relations.get().contains(LinkRelations::PRELOAD) {
348                    if let AttributeMutation::Set(Some(_), _) = mutation {
349                        self.handle_preload_url();
350                    }
351                }
352            },
353            local_name!("type") => {
354                // https://html.spec.whatwg.org/multipage/#link-type-stylesheet:fetch-and-process-the-linked-resource
355                // When the type attribute of the link element of an external resource link that
356                // is already browsing-context connected is set or changed to a value that does
357                // not or no longer matches the Content-Type metadata of the previous obtained
358                // external resource, if any.
359                //
360                // TODO: Match Content-Type metadata to check if it needs to be updated
361                if self.relations.get().contains(LinkRelations::STYLESHEET) {
362                    self.handle_stylesheet_url();
363                }
364
365                // https://html.spec.whatwg.org/multipage/#link-type-preload
366                // When the type attribute of the link element of an external resource link that
367                // is already browsing-context connected, but was previously not obtained due to
368                // the type attribute specifying an unsupported type for the request destination,
369                // is set, removed, or changed.
370                if self.relations.get().contains(LinkRelations::PRELOAD) &&
371                    !self.previous_type_matched.get()
372                {
373                    self.handle_preload_url();
374                }
375            },
376            local_name!("media") => {
377                // https://html.spec.whatwg.org/multipage/#link-type-preload
378                // When the media attribute of the link element of an external resource link that
379                // is already browsing-context connected, but was previously not obtained due to
380                // the media attribute not matching the environment, is changed or removed.
381                if self.relations.get().contains(LinkRelations::PRELOAD) &&
382                    !self.previous_media_environment_matched.get()
383                {
384                    match mutation {
385                        AttributeMutation::Removed | AttributeMutation::Set(Some(_), _) => {
386                            self.handle_preload_url()
387                        },
388                        _ => {},
389                    };
390                } else if self.relations.get().contains(LinkRelations::STYLESHEET) {
391                    if let Some(ref stylesheet) = *self.stylesheet.borrow_mut() {
392                        let document = self.owner_document();
393                        let shared_lock = document.style_shared_lock().clone();
394                        let mut guard = shared_lock.write();
395                        let media = stylesheet.media.write_with(&mut guard);
396                        match mutation {
397                            AttributeMutation::Set(..) => {
398                                *media =
399                                    MediaList::parse_media_list(&attr.value(), document.window())
400                            },
401                            AttributeMutation::Removed => *media = StyleMediaList::empty(),
402                        };
403                        self.owner_document().invalidate_stylesheets();
404                    }
405                }
406
407                let matches_media_environment =
408                    MediaList::matches_environment(&self.owner_document(), &attr.value());
409                self.previous_media_environment_matched
410                    .set(matches_media_environment);
411            },
412            _ => {},
413        }
414    }
415
416    fn parse_plain_attribute(&self, name: &LocalName, value: DOMString) -> AttrValue {
417        match name {
418            &local_name!("rel") => AttrValue::from_serialized_tokenlist(value.into()),
419            _ => self
420                .super_type()
421                .unwrap()
422                .parse_plain_attribute(name, value),
423        }
424    }
425
426    fn bind_to_tree(&self, context: &BindContext, can_gc: CanGc) {
427        if let Some(s) = self.super_type() {
428            s.bind_to_tree(context, can_gc);
429        }
430
431        self.relations
432            .set(LinkRelations::for_element(self.upcast()));
433
434        if context.tree_connected {
435            let element = self.upcast();
436
437            if let Some(href) = get_attr(element, &local_name!("href")) {
438                let relations = self.relations.get();
439                // https://html.spec.whatwg.org/multipage/#link-type-stylesheet:fetch-and-process-the-linked-resource
440                // > When the external resource link's link element becomes browsing-context connected.
441                if relations.contains(LinkRelations::STYLESHEET) {
442                    self.handle_stylesheet_url();
443                }
444
445                if relations.contains(LinkRelations::ICON) {
446                    self.handle_favicon_url(&href);
447                }
448
449                if relations.contains(LinkRelations::PREFETCH) {
450                    self.fetch_and_process_prefetch_link(&href);
451                }
452
453                if relations.contains(LinkRelations::PRELOAD) {
454                    self.handle_preload_url();
455                }
456            }
457        }
458    }
459
460    fn unbind_from_tree(&self, context: &UnbindContext, can_gc: CanGc) {
461        if let Some(s) = self.super_type() {
462            s.unbind_from_tree(context, can_gc);
463        }
464
465        self.remove_stylesheet();
466    }
467}
468
469impl HTMLLinkElement {
470    fn compute_destination_for_attribute(&self) -> Option<Destination> {
471        // Let destination be the result of translating the keyword
472        // representing the state of el's as attribute.
473        let element = self.upcast::<Element>();
474        element
475            .get_attribute(&local_name!("as"))
476            .and_then(|attr| LinkProcessingOptions::translate_a_preload_destination(&attr.value()))
477    }
478
479    /// <https://html.spec.whatwg.org/multipage/#create-link-options-from-element>
480    fn processing_options(&self) -> LinkProcessingOptions {
481        let element = self.upcast::<Element>();
482
483        // Step 1. Let document be el's node document.
484        let document = self.upcast::<Node>().owner_doc();
485        let global = document.owner_global();
486
487        // Step 2. Let options be a new link processing options
488        let mut options = LinkProcessingOptions {
489            href: String::new(),
490            destination: Destination::None,
491            integrity: String::new(),
492            link_type: String::new(),
493            cryptographic_nonce_metadata: self.upcast::<Element>().nonce_value(),
494            cross_origin: cors_setting_for_element(element),
495            referrer_policy: referrer_policy_for_element(element),
496            policy_container: document.policy_container().to_owned(),
497            source_set: None, // FIXME
498            origin: document.borrow().origin().immutable().to_owned(),
499            base_url: document.borrow().base_url(),
500            insecure_requests_policy: document.insecure_requests_policy(),
501            has_trustworthy_ancestor_origin: document.has_trustworthy_ancestor_or_current_origin(),
502            request_client: global.request_client(),
503            referrer: global.get_referrer(),
504        };
505
506        // Step 3. If el has an href attribute, then set options's href to the value of el's href attribute.
507        if let Some(href_attribute) = element.get_attribute(&local_name!("href")) {
508            options.href = (**href_attribute.value()).to_owned();
509        }
510
511        // Step 4. If el has an integrity attribute, then set options's integrity
512        //         to the value of el's integrity content attribute.
513        if let Some(integrity_attribute) = element.get_attribute(&local_name!("integrity")) {
514            options.integrity = (**integrity_attribute.value()).to_owned();
515        }
516
517        // Step 5. If el has a type attribute, then set options's type to the value of el's type attribute.
518        if let Some(type_attribute) = element.get_attribute(&local_name!("type")) {
519            options.link_type = (**type_attribute.value()).to_owned();
520        }
521
522        // Step 6. Assert: options's href is not the empty string, or options's source set is not null.
523        assert!(!options.href.is_empty() || options.source_set.is_some());
524
525        // Step 7. Return options.
526        options
527    }
528
529    /// <https://html.spec.whatwg.org/multipage/#default-fetch-and-process-the-linked-resource>
530    ///
531    /// This method does not implement Step 7 (fetching the request) and instead returns the [RequestBuilder],
532    /// as the fetch context that should be used depends on the link type.
533    fn default_fetch_and_process_the_linked_resource(&self) -> Option<RequestBuilder> {
534        // Step 1. Let options be the result of creating link options from el.
535        let options = self.processing_options();
536
537        // Step 2. Let request be the result of creating a link request given options.
538        let Some(request) = options.create_link_request(self.owner_window().webview_id()) else {
539            // Step 3. If request is null, then return.
540            return None;
541        };
542        // Step 4. Set request's synchronous flag.
543        let mut request = request.synchronous(true);
544
545        // Step 5. Run the linked resource fetch setup steps, given el and request. If the result is false, then return.
546        if !self.linked_resource_fetch_setup(&mut request) {
547            return None;
548        }
549
550        // TODO Step 6. Set request's initiator type to "css" if el's rel attribute
551        // contains the keyword stylesheet; "link" otherwise.
552
553        // Step 7. Fetch request with processResponseConsumeBody set to the following steps given response response and null,
554        // failure, or a byte sequence bodyBytes: [..]
555        Some(request)
556    }
557
558    /// <https://html.spec.whatwg.org/multipage/#linked-resource-fetch-setup-steps>
559    fn linked_resource_fetch_setup(&self, request: &mut RequestBuilder) -> bool {
560        // https://html.spec.whatwg.org/multipage/#rel-icon:linked-resource-fetch-setup-steps
561        if self.relations.get().contains(LinkRelations::ICON) {
562            // Step 1. Set request's destination to "image".
563            request.destination = Destination::Image;
564
565            // Step 2. Return true.
566            //
567            // Fall-through
568        }
569
570        // https://html.spec.whatwg.org/multipage/#link-type-stylesheet:linked-resource-fetch-setup-steps
571        if self.relations.get().contains(LinkRelations::STYLESHEET) {
572            // Step 1. If el's disabled attribute is set, then return false.
573            if self
574                .upcast::<Element>()
575                .has_attribute(&local_name!("disabled"))
576            {
577                return false;
578            }
579            // Step 2. If el contributes a script-blocking style sheet, append el to its node document's script-blocking style sheet set.
580            //
581            // Implemented in `ElementStylesheetLoader::load_with_element`.
582
583            // Step 3. If el's media attribute's value matches the environment and el is potentially render-blocking, then block rendering on el.
584            //
585            // Implemented in `ElementStylesheetLoader::load_with_element`.
586
587            // Step 4. If el is currently render-blocking, then set request's render-blocking to true.
588            // TODO
589
590            // Step 5. Return true.
591            //
592            // Fall-through
593        }
594
595        true
596    }
597
598    /// The `fetch and process the linked resource` algorithm for [`rel="prefetch"`](https://html.spec.whatwg.org/multipage/#link-type-prefetch)
599    fn fetch_and_process_prefetch_link(&self, href: &str) {
600        // Step 1. If el's href attribute's value is the empty string, then return.
601        if href.is_empty() {
602            return;
603        }
604
605        // Step 2. Let options be the result of creating link options from el.
606        let mut options = self.processing_options();
607
608        // Step 3. Set options's destination to the empty string.
609        options.destination = Destination::None;
610
611        // Step 4. Let request be the result of creating a link request given options.
612        let Some(request) = options.create_link_request(self.owner_window().webview_id()) else {
613            // Step 5. If request is null, then return.
614            return;
615        };
616        let url = request.url.clone();
617
618        // Step 6. Set request's initiator to "prefetch".
619        let request = request.initiator(Initiator::Prefetch);
620
621        // (Step 7, firing load/error events is handled in the FetchResponseListener impl for LinkFetchContext)
622
623        // Step 8. The user agent should fetch request, with processResponseConsumeBody set to processPrefetchResponse.
624        let document = self.upcast::<Node>().owner_doc();
625        let fetch_context = LinkFetchContext {
626            url,
627            link: Some(Trusted::new(self)),
628            document: Trusted::new(&document),
629            global: Trusted::new(&document.global()),
630            type_: LinkFetchContextType::Prefetch,
631            response_body: vec![],
632        };
633
634        document.fetch_background(request, fetch_context);
635    }
636
637    /// <https://html.spec.whatwg.org/multipage/#concept-link-obtain>
638    fn handle_stylesheet_url(&self) {
639        let document = self.owner_document();
640        if document.browsing_context().is_none() {
641            return;
642        }
643
644        let element = self.upcast::<Element>();
645
646        // https://html.spec.whatwg.org/multipage/#processing-the-type-attribute
647        // > If the UA does not support the given MIME type for the given link relationship,
648        // > then the UA should not fetch and process the linked resource
649        //
650        // https://html.spec.whatwg.org/multipage/#link-type-stylesheet
651        // > The default type for resources given by the stylesheet keyword is text/css.
652        let type_ = element.get_string_attribute(&local_name!("type"));
653        if !type_.is_empty() && type_ != "text/css" {
654            return;
655        }
656
657        // Step 1.
658        let href = element.get_string_attribute(&local_name!("href"));
659        if href.is_empty() {
660            return;
661        }
662
663        // Step 2.
664        let link_url = match document.base_url().join(&href.str()) {
665            Ok(url) => url,
666            Err(e) => {
667                debug!("Parsing url {} failed: {}", href, e);
668                return;
669            },
670        };
671
672        // Step 3
673        let cors_setting = cors_setting_for_element(element);
674
675        let mq_attribute = element.get_attribute(&local_name!("media"));
676        let value = mq_attribute.as_ref().map(|a| a.value());
677        let mq_str = match value {
678            Some(ref value) => &***value,
679            None => "",
680        };
681
682        let media = MediaList::parse_media_list(mq_str, document.window());
683        let media = Arc::new(document.style_shared_lock().wrap(media));
684
685        let im_attribute = element.get_attribute(&local_name!("integrity"));
686        let integrity_val = im_attribute.as_ref().map(|a| a.value());
687        let integrity_metadata = match integrity_val {
688            Some(ref value) => &***value,
689            None => "",
690        };
691
692        self.request_generation_id
693            .set(self.request_generation_id.get().increment());
694        self.pending_loads.set(0);
695
696        ElementStylesheetLoader::load_with_element(
697            self.upcast(),
698            StylesheetContextSource::LinkElement,
699            media,
700            link_url,
701            cors_setting,
702            integrity_metadata.to_owned(),
703        );
704    }
705
706    /// <https://html.spec.whatwg.org/multipage/#attr-link-disabled>
707    fn handle_disabled_attribute_change(&self, is_removal: bool) {
708        // > Whenever the disabled attribute is removed, set the link element's explicitly enabled attribute to true.
709        if is_removal {
710            self.is_explicitly_enabled.set(true);
711        }
712        if let Some(stylesheet) = self.get_stylesheet() {
713            if stylesheet.set_disabled(!is_removal) {
714                self.stylesheet_list_owner().invalidate_stylesheets();
715            }
716        }
717    }
718
719    fn handle_favicon_url(&self, href: &str) {
720        // If el's href attribute's value is the empty string, then return.
721        if href.is_empty() {
722            return;
723        }
724
725        // The spec does not specify this, but we don't fetch favicons for iframes, as
726        // they won't be displayed anyways.
727        let window = self.owner_window();
728        if !window.is_top_level() {
729            return;
730        }
731        let Ok(href) = self.Href().parse() else {
732            return;
733        };
734
735        // Ignore all previous fetch operations
736        self.request_generation_id
737            .set(self.request_generation_id.get().increment());
738
739        let cache_result = window.image_cache().get_cached_image_status(
740            href,
741            window.origin().immutable().clone(),
742            cors_setting_for_element(self.upcast()),
743        );
744
745        match cache_result {
746            ImageCacheResult::Available(ImageOrMetadataAvailable::ImageAvailable {
747                image, ..
748            }) => {
749                self.process_favicon_response(image);
750            },
751            ImageCacheResult::Available(ImageOrMetadataAvailable::MetadataAvailable(_, id)) |
752            ImageCacheResult::Pending(id) => {
753                let sender = self.register_image_cache_callback(id);
754                window.image_cache().add_listener(ImageLoadListener::new(
755                    sender,
756                    window.pipeline_id(),
757                    id,
758                ));
759            },
760            ImageCacheResult::ReadyForRequest(id) => {
761                let Some(request) = self.default_fetch_and_process_the_linked_resource() else {
762                    return;
763                };
764
765                let sender = self.register_image_cache_callback(id);
766                window.image_cache().add_listener(ImageLoadListener::new(
767                    sender,
768                    window.pipeline_id(),
769                    id,
770                ));
771
772                let document = self.upcast::<Node>().owner_doc();
773                let fetch_context = FaviconFetchContext {
774                    url: self.owner_document().base_url(),
775                    image_cache: window.image_cache(),
776                    id,
777                    link: Trusted::new(self),
778                };
779                document.fetch_background(request, fetch_context);
780            },
781            ImageCacheResult::FailedToLoadOrDecode => {},
782        };
783    }
784
785    fn register_image_cache_callback(&self, id: PendingImageId) -> ImageCacheResponseCallback {
786        let trusted_node = Trusted::new(self);
787        let window = self.owner_window();
788        let request_generation_id = self.get_request_generation_id();
789        window.register_image_cache_listener(id, move |response, _| {
790            let trusted_node = trusted_node.clone();
791            let link_element = trusted_node.root();
792            let window = link_element.owner_window();
793
794            let ImageResponse::Loaded(image, _) = response.response else {
795                // We don't care about metadata and such for favicons.
796                return;
797            };
798
799            if request_generation_id != link_element.get_request_generation_id() {
800                // This load is no longer relevant.
801                return;
802            };
803
804            window
805                .as_global_scope()
806                .task_manager()
807                .networking_task_source()
808                .queue(task!(process_favicon_response: move || {
809                    let element = trusted_node.root();
810
811                    if request_generation_id != element.get_request_generation_id() {
812                        // This load is no longer relevant.
813                        return;
814                    };
815
816                    element.process_favicon_response(image);
817                }));
818        })
819    }
820
821    /// Rasterizes a loaded favicon file if necessary and notifies the embedder about it.
822    fn process_favicon_response(&self, image: Image) {
823        // TODO: Include the size attribute here
824        let window = self.owner_window();
825        let document = self.owner_document();
826
827        let send_rasterized_favicon_to_embedder = |raster_image: &pixels::RasterImage| {
828            // Let's not worry about animated favicons...
829            let frame = raster_image.first_frame();
830
831            let format = match raster_image.format {
832                PixelFormat::K8 => embedder_traits::PixelFormat::K8,
833                PixelFormat::KA8 => embedder_traits::PixelFormat::KA8,
834                PixelFormat::RGB8 => embedder_traits::PixelFormat::RGB8,
835                PixelFormat::RGBA8 => embedder_traits::PixelFormat::RGBA8,
836                PixelFormat::BGRA8 => embedder_traits::PixelFormat::BGRA8,
837            };
838
839            let embedder_image = embedder_traits::Image::new(
840                frame.width,
841                frame.height,
842                std::sync::Arc::new(GenericSharedMemory::from_bytes(&raster_image.bytes)),
843                raster_image.frames[0].byte_range.clone(),
844                format,
845            );
846            document.set_favicon(embedder_image);
847        };
848
849        match image {
850            Image::Raster(raster_image) => send_rasterized_favicon_to_embedder(&raster_image),
851            Image::Vector(vector_image) => {
852                // This size is completely arbitrary.
853                let size = DeviceIntSize::new(250, 250);
854
855                let image_cache = window.image_cache();
856                if let Some(raster_image) =
857                    image_cache.rasterize_vector_image(vector_image.id, size, None)
858                {
859                    send_rasterized_favicon_to_embedder(&raster_image);
860                } else {
861                    // The rasterization callback will end up calling "process_favicon_response" again,
862                    // but this time with a raster image.
863                    let image_cache_sender = self.register_image_cache_callback(vector_image.id);
864                    image_cache.add_rasterization_complete_listener(
865                        window.pipeline_id(),
866                        vector_image.id,
867                        size,
868                        image_cache_sender,
869                    );
870                }
871            },
872        }
873    }
874
875    /// <https://html.spec.whatwg.org/multipage/#link-type-preload:fetch-and-process-the-linked-resource-2>
876    /// and type matching destination steps of <https://html.spec.whatwg.org/multipage/#preload>
877    fn handle_preload_url(&self) {
878        // Step 1. Update the source set for el.
879        // TODO
880        // Step 2. Let options be the result of creating link options from el.
881        let mut options = self.processing_options();
882        // Step 3. Let destination be the result of translating the keyword
883        // representing the state of el's as attribute.
884        let Some(destination) = self.compute_destination_for_attribute() else {
885            // Step 4. If destination is null, then return.
886            return;
887        };
888        // Step 5. Set options's destination to destination.
889        options.destination = destination;
890        // Steps for https://html.spec.whatwg.org/multipage/#preload
891        {
892            // Step 1. If options's type doesn't match options's destination, then return.
893            let type_matches_destination = options.type_matches_destination();
894            self.previous_type_matched.set(type_matches_destination);
895            if !type_matches_destination {
896                return;
897            }
898        }
899        // Step 6. Preload options, with the following steps given a response response:
900        let document = self.upcast::<Node>().owner_doc();
901        options.preload(
902            self.owner_window().webview_id(),
903            Some(Trusted::new(self)),
904            &document,
905        );
906    }
907
908    /// <https://html.spec.whatwg.org/multipage/#link-type-preload:fetch-and-process-the-linked-resource-2>
909    pub(crate) fn fire_event_after_response(
910        &self,
911        response: Result<(), NetworkError>,
912        can_gc: CanGc,
913    ) {
914        // Step 3.1 If response is a network error, fire an event named error at el.
915        // Otherwise, fire an event named load at el.
916        if response.is_err() {
917            self.upcast::<EventTarget>()
918                .fire_event(atom!("error"), can_gc);
919        } else {
920            self.upcast::<EventTarget>()
921                .fire_event(atom!("load"), can_gc);
922        }
923    }
924}
925
926impl StylesheetOwner for HTMLLinkElement {
927    fn increment_pending_loads_count(&self) {
928        self.pending_loads.set(self.pending_loads.get() + 1)
929    }
930
931    fn load_finished(&self, succeeded: bool) -> Option<bool> {
932        assert!(self.pending_loads.get() > 0, "What finished?");
933        if !succeeded {
934            self.any_failed_load.set(true);
935        }
936
937        self.pending_loads.set(self.pending_loads.get() - 1);
938        if self.pending_loads.get() != 0 {
939            return None;
940        }
941
942        let any_failed = self.any_failed_load.get();
943        self.any_failed_load.set(false);
944        Some(any_failed)
945    }
946
947    fn parser_inserted(&self) -> bool {
948        self.parser_inserted.get()
949    }
950
951    /// <https://html.spec.whatwg.org/multipage/#potentially-render-blocking>
952    fn potentially_render_blocking(&self) -> bool {
953        // An element is potentially render-blocking if its blocking tokens set contains "render",
954        // or if it is implicitly potentially render-blocking, which will be defined at the individual elements.
955        // By default, an element is not implicitly potentially render-blocking.
956        //
957        // https://html.spec.whatwg.org/multipage/#link-type-stylesheet:implicitly-potentially-render-blocking
958        // > A link element of this type is implicitly potentially render-blocking if the element was created by its node document's parser.
959        self.parser_inserted() ||
960            self.blocking
961                .get()
962                .is_some_and(|list| list.Contains("render".into()))
963    }
964
965    fn referrer_policy(&self) -> ReferrerPolicy {
966        if self.RelList(CanGc::note()).Contains("noreferrer".into()) {
967            return ReferrerPolicy::NoReferrer;
968        }
969
970        ReferrerPolicy::EmptyString
971    }
972
973    fn set_origin_clean(&self, origin_clean: bool) {
974        if let Some(stylesheet) = self.get_cssom_stylesheet(CanGc::note()) {
975            stylesheet.set_origin_clean(origin_clean);
976        }
977    }
978}
979
980impl HTMLLinkElementMethods<crate::DomTypeHolder> for HTMLLinkElement {
981    // https://html.spec.whatwg.org/multipage/#dom-link-href
982    make_url_getter!(Href, "href");
983
984    // https://html.spec.whatwg.org/multipage/#dom-link-href
985    make_url_setter!(SetHref, "href");
986
987    // https://html.spec.whatwg.org/multipage/#dom-link-rel
988    make_getter!(Rel, "rel");
989
990    /// <https://html.spec.whatwg.org/multipage/#dom-link-rel>
991    fn SetRel(&self, rel: DOMString, can_gc: CanGc) {
992        self.upcast::<Element>()
993            .set_tokenlist_attribute(&local_name!("rel"), rel, can_gc);
994    }
995
996    // https://html.spec.whatwg.org/multipage/#dom-link-as
997    make_enumerated_getter!(
998        As,
999        "as",
1000        "fetch" | "audio" | "audioworklet" | "document" | "embed" | "font" | "frame"
1001            | "iframe" | "image" | "json" | "manifest" | "object" | "paintworklet"
1002            | "report" | "script" | "serviceworker" | "sharedworker" | "style" | "track"
1003            | "video" | "webidentity" | "worker" | "xslt",
1004        missing => "",
1005        invalid => ""
1006    );
1007
1008    // https://html.spec.whatwg.org/multipage/#dom-link-as
1009    make_setter!(SetAs, "as");
1010
1011    // https://html.spec.whatwg.org/multipage/#dom-link-media
1012    make_getter!(Media, "media");
1013
1014    // https://html.spec.whatwg.org/multipage/#dom-link-media
1015    make_setter!(SetMedia, "media");
1016
1017    // https://html.spec.whatwg.org/multipage/#dom-link-integrity
1018    make_getter!(Integrity, "integrity");
1019
1020    // https://html.spec.whatwg.org/multipage/#dom-link-integrity
1021    make_setter!(SetIntegrity, "integrity");
1022
1023    // https://html.spec.whatwg.org/multipage/#dom-link-hreflang
1024    make_getter!(Hreflang, "hreflang");
1025
1026    // https://html.spec.whatwg.org/multipage/#dom-link-hreflang
1027    make_setter!(SetHreflang, "hreflang");
1028
1029    // https://html.spec.whatwg.org/multipage/#dom-link-type
1030    make_getter!(Type, "type");
1031
1032    // https://html.spec.whatwg.org/multipage/#dom-link-type
1033    make_setter!(SetType, "type");
1034
1035    // https://html.spec.whatwg.org/multipage/#dom-link-disabled
1036    make_bool_getter!(Disabled, "disabled");
1037
1038    // https://html.spec.whatwg.org/multipage/#dom-link-disabled
1039    make_bool_setter!(SetDisabled, "disabled");
1040
1041    /// <https://html.spec.whatwg.org/multipage/#dom-link-rellist>
1042    fn RelList(&self, can_gc: CanGc) -> DomRoot<DOMTokenList> {
1043        self.rel_list.or_init(|| {
1044            DOMTokenList::new(
1045                self.upcast(),
1046                &local_name!("rel"),
1047                Some(vec![
1048                    Atom::from("alternate"),
1049                    Atom::from("apple-touch-icon"),
1050                    Atom::from("apple-touch-icon-precomposed"),
1051                    Atom::from("canonical"),
1052                    Atom::from("dns-prefetch"),
1053                    Atom::from("icon"),
1054                    Atom::from("import"),
1055                    Atom::from("manifest"),
1056                    Atom::from("modulepreload"),
1057                    Atom::from("next"),
1058                    Atom::from("preconnect"),
1059                    Atom::from("prefetch"),
1060                    Atom::from("preload"),
1061                    Atom::from("prerender"),
1062                    Atom::from("stylesheet"),
1063                ]),
1064                can_gc,
1065            )
1066        })
1067    }
1068
1069    // https://html.spec.whatwg.org/multipage/#dom-link-charset
1070    make_getter!(Charset, "charset");
1071
1072    // https://html.spec.whatwg.org/multipage/#dom-link-charset
1073    make_setter!(SetCharset, "charset");
1074
1075    // https://html.spec.whatwg.org/multipage/#dom-link-rev
1076    make_getter!(Rev, "rev");
1077
1078    // https://html.spec.whatwg.org/multipage/#dom-link-rev
1079    make_setter!(SetRev, "rev");
1080
1081    // https://html.spec.whatwg.org/multipage/#dom-link-target
1082    make_getter!(Target, "target");
1083
1084    // https://html.spec.whatwg.org/multipage/#dom-link-target
1085    make_setter!(SetTarget, "target");
1086
1087    /// <https://html.spec.whatwg.org/multipage/#attr-link-blocking>
1088    fn Blocking(&self, can_gc: CanGc) -> DomRoot<DOMTokenList> {
1089        self.blocking.or_init(|| {
1090            DOMTokenList::new(
1091                self.upcast(),
1092                &local_name!("blocking"),
1093                Some(vec![Atom::from("render")]),
1094                can_gc,
1095            )
1096        })
1097    }
1098
1099    /// <https://html.spec.whatwg.org/multipage/#dom-link-crossorigin>
1100    fn GetCrossOrigin(&self) -> Option<DOMString> {
1101        reflect_cross_origin_attribute(self.upcast::<Element>())
1102    }
1103
1104    /// <https://html.spec.whatwg.org/multipage/#dom-link-crossorigin>
1105    fn SetCrossOrigin(&self, cx: &mut JSContext, value: Option<DOMString>) {
1106        set_cross_origin_attribute(cx, self.upcast::<Element>(), value);
1107    }
1108
1109    /// <https://html.spec.whatwg.org/multipage/#dom-link-referrerpolicy>
1110    fn ReferrerPolicy(&self) -> DOMString {
1111        reflect_referrer_policy_attribute(self.upcast::<Element>())
1112    }
1113
1114    // https://html.spec.whatwg.org/multipage/#dom-link-referrerpolicy
1115    make_setter!(SetReferrerPolicy, "referrerpolicy");
1116
1117    /// <https://drafts.csswg.org/cssom/#dom-linkstyle-sheet>
1118    fn GetSheet(&self, can_gc: CanGc) -> Option<DomRoot<DOMStyleSheet>> {
1119        self.get_cssom_stylesheet(can_gc).map(DomRoot::upcast)
1120    }
1121}
1122
1123struct FaviconFetchContext {
1124    /// The `<link>` element that caused this fetch operation
1125    link: Trusted<HTMLLinkElement>,
1126    image_cache: std::sync::Arc<dyn ImageCache>,
1127    id: PendingImageId,
1128
1129    /// The base url of the document that the `<link>` element belongs to.
1130    url: ServoUrl,
1131}
1132
1133impl FetchResponseListener for FaviconFetchContext {
1134    fn process_request_body(&mut self, _: RequestId) {}
1135
1136    fn process_request_eof(&mut self, _: RequestId) {}
1137
1138    fn process_response(
1139        &mut self,
1140        request_id: RequestId,
1141        metadata: Result<FetchMetadata, NetworkError>,
1142    ) {
1143        self.image_cache.notify_pending_response(
1144            self.id,
1145            FetchResponseMsg::ProcessResponse(request_id, metadata.clone()),
1146        );
1147    }
1148
1149    fn process_response_chunk(&mut self, request_id: RequestId, chunk: Vec<u8>) {
1150        self.image_cache.notify_pending_response(
1151            self.id,
1152            FetchResponseMsg::ProcessResponseChunk(request_id, chunk.into()),
1153        );
1154    }
1155
1156    fn process_response_eof(
1157        self,
1158        cx: &mut js::context::JSContext,
1159        request_id: RequestId,
1160        response: Result<(), NetworkError>,
1161        timing: ResourceFetchTiming,
1162    ) {
1163        self.image_cache.notify_pending_response(
1164            self.id,
1165            FetchResponseMsg::ProcessResponseEOF(request_id, response.clone(), timing.clone()),
1166        );
1167        submit_timing(&self, &response, &timing, CanGc::from_cx(cx));
1168    }
1169
1170    fn process_csp_violations(&mut self, _request_id: RequestId, violations: Vec<Violation>) {
1171        let global = &self.resource_timing_global();
1172        global.report_csp_violations(violations, None, None);
1173    }
1174}
1175
1176impl ResourceTimingListener for FaviconFetchContext {
1177    fn resource_timing_information(&self) -> (InitiatorType, ServoUrl) {
1178        (
1179            InitiatorType::LocalName("link".to_string()),
1180            self.url.clone(),
1181        )
1182    }
1183
1184    fn resource_timing_global(&self) -> DomRoot<GlobalScope> {
1185        self.link.root().upcast::<Node>().owner_doc().global()
1186    }
1187}
script/dom/html/htmllinkelement.rs

script/dom/html/
htmllinkelement.rs
