script/dom/html/form_controls/

htmloptionelement.rs

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

use std::cell::Cell;
use std::convert::TryInto;

use dom_struct::dom_struct;
use html5ever::{LocalName, Prefix, QualName, local_name, ns};
use js::context::{JSContext, NoGC};
use js::rust::HandleObject;
use script_bindings::dom::{MutNullableDom, UnrootedDom};
use script_bindings::root::Dom;
use style::str::{split_html_space_chars, str_join};
use stylo_dom::ElementState;

use crate::dom::bindings::codegen::Bindings::CharacterDataBinding::CharacterDataMethods;
use crate::dom::bindings::codegen::Bindings::HTMLOptionElementBinding::HTMLOptionElementMethods;
use crate::dom::bindings::codegen::Bindings::HTMLSelectElementBinding::HTMLSelectElement_Binding::HTMLSelectElementMethods;
use crate::dom::bindings::codegen::Bindings::NodeBinding::NodeMethods;
use crate::dom::bindings::codegen::Bindings::WindowBinding::WindowMethods;
use crate::dom::bindings::error::Fallible;
use crate::dom::bindings::inheritance::Castable;
use crate::dom::bindings::reflector::DomGlobal;
use crate::dom::bindings::root::DomRoot;
use crate::dom::bindings::str::DOMString;
use crate::dom::characterdata::CharacterData;
use crate::dom::document::Document;
use crate::dom::element::attributes::storage::AttrRef;
use crate::dom::element::{AttributeMutation, CustomElementCreationMode, Element, ElementCreator};
use crate::dom::html::htmlelement::HTMLElement;
use crate::dom::html::htmlformelement::HTMLFormElement;
use crate::dom::html::htmloptgroupelement::HTMLOptGroupElement;
use crate::dom::html::htmlscriptelement::HTMLScriptElement;
use crate::dom::html::htmlselectelement::HTMLSelectElement;
use crate::dom::iterators::ShadowIncluding;
use crate::dom::node::virtualmethods::VirtualMethods;
use crate::dom::node::{
    BindContext, ChildrenMutation, CloneChildrenFlag, MoveContext, Node, NodeTraits, UnbindContext,
};
use crate::dom::text::Text;
use crate::dom::types::DocumentFragment;
use crate::dom::validation::Validatable;
use crate::dom::validitystate::ValidationFlags;
use crate::dom::window::Window;
use crate::realms::enter_auto_realm;
use crate::runtime::job_queue::MicrotaskRunnable;

#[dom_struct]
pub(crate) struct HTMLOptionElement {
    htmlelement: HTMLElement,

    /// <https://html.spec.whatwg.org/multipage/#attr-option-selected>
    selectedness: Cell<bool>,

    /// <https://html.spec.whatwg.org/multipage/#concept-option-dirtiness>
    dirtiness: Cell<bool>,

    /// <https://html.spec.whatwg.org/multipage/#cached-nearest-ancestor-select-element>
    cached_nearest_ancestor_select: MutNullableDom<HTMLSelectElement>,
}

impl HTMLOptionElement {
    fn new_inherited(
        local_name: LocalName,
        prefix: Option<Prefix>,
        document: &Document,
    ) -> HTMLOptionElement {
        HTMLOptionElement {
            htmlelement: HTMLElement::new_inherited_with_state(
                ElementState::ENABLED,
                local_name,
                prefix,
                document,
            ),
            selectedness: Cell::new(false),
            dirtiness: Cell::new(false),
            cached_nearest_ancestor_select: MutNullableDom::default(),
        }
    }

    pub(crate) fn new(
        cx: &mut js::context::JSContext,
        local_name: LocalName,
        prefix: Option<Prefix>,
        document: &Document,
        proto: Option<HandleObject>,
    ) -> DomRoot<HTMLOptionElement> {
        Node::reflect_node_with_proto(
            cx,
            Box::new(HTMLOptionElement::new_inherited(
                local_name, prefix, document,
            )),
            document,
            proto,
        )
    }

    /// Set the selectedness value of this [`HTMLOptionElement`] returning true if anything
    /// changed.
    ///
    /// Note: This *does not* update the containing `<select>` element.
    pub(crate) fn set_selectedness(&self, no_gc: &NoGC, selected: bool) -> bool {
        if selected == self.selectedness.get() {
            return false;
        }

        self.selectedness.set(selected);
        self.upcast::<Element>()
            .set_state(no_gc, ElementState::CHECKED, selected);
        // Bump the tree version so that any live HTMLCollection (e.g. selectedOptions)
        // rooted at an ancestor invalidates its cached length and cursor.
        self.upcast::<Node>().rev_version(no_gc);
        true
    }

    pub(crate) fn set_dirtiness(&self, dirtiness: bool) {
        self.dirtiness.set(dirtiness);
    }

    /// From <https://html.spec.whatwg.org/multipage/#the-select-element>:
    ///
    /// > If the multiple attribute is absent, whenever an option element in the select element's
    /// > list of options has its selectedness set to true, and whenever an option element with its
    /// > selectedness set to true is added to the select element's list of options, the user agent
    /// > must set the selectedness of all the other option elements in its list of options to
    /// > false.
    fn pick_if_selected_in_select(&self, cx: &mut JSContext, select: &HTMLSelectElement) {
        if !self.Selected() {
            return;
        }

        debug_assert!(
            select
                .list_of_options(cx.no_gc())
                .any(|option| *option == self)
        );
        select.pick_option(cx.no_gc(), self);

        // This is not specified, but Servo needs to update the cached validity state and shadow
        // tree of select elements when their descendants change.
        select
            .validity_state(cx)
            .perform_validation_and_update(cx, ValidationFlags::all());
        select.update_shadow_tree(cx);
    }

    fn pick_if_selected_in_cached_select(&self, cx: &mut JSContext) {
        let select = self.cached_nearest_ancestor_select.get();
        debug_assert!(select == self.nearest_ancestor_select());
        if let Some(select) = select {
            self.pick_if_selected_in_select(cx, &select);
        }
    }

    /// <https://html.spec.whatwg.org/multipage/#concept-option-index>
    fn index(&self, no_gc: &NoGC) -> i32 {
        let Some(owner_select) = self.cached_nearest_ancestor_select() else {
            return 0;
        };

        let Some(position) = owner_select.list_of_options(no_gc).position(|n| *n == self) else {
            // An option should always be in it's owner's list of options, but it's not worth a browser panic
            warn!("HTMLOptionElement called index_in_select at a select that did not contain it");
            return 0;
        };

        position.try_into().unwrap_or(0)
    }

    fn update_select_validity(&self, cx: &mut JSContext) {
        if let Some(select) = self.cached_nearest_ancestor_select() {
            select
                .validity_state(cx)
                .perform_validation_and_update(cx, ValidationFlags::all());
        }
    }

    /// <https://html.spec.whatwg.org/multipage/#concept-option-label>
    ///
    /// Note that this is not equivalent to <https://html.spec.whatwg.org/multipage/#dom-option-label>.
    pub(crate) fn displayed_label(&self) -> DOMString {
        // > The label of an option element is the value of the label content attribute, if there is one
        // > and its value is not the empty string, or, otherwise, the value of the element's text IDL attribute.
        let label = self
            .upcast::<Element>()
            .get_string_attribute(&local_name!("label"));

        if label.is_empty() {
            return self.Text();
        }

        label
    }

    /// <https://html.spec.whatwg.org/multipage/#cached-nearest-ancestor-select-element>
    pub(crate) fn cached_nearest_ancestor_select(&self) -> Option<DomRoot<HTMLSelectElement>> {
        self.cached_nearest_ancestor_select.get()
    }

    /// <https://html.spec.whatwg.org/multipage/#option-element-nearest-ancestor-select>
    pub(crate) fn nearest_ancestor_select(&self) -> Option<DomRoot<HTMLSelectElement>> {
        // Step 1. Let ancestorOptgroup be null.
        // NOTE: We only care whether the value is non-null, so a boolean is enough
        let mut did_see_ancestor_optgroup = false;

        // Step 2. For each ancestor of option's ancestors, in reverse tree order:
        for ancestor in self
            .upcast::<Node>()
            .ancestors()
            .filter_map(DomRoot::downcast::<Element>)
        {
            // Step 2.1 If ancestor is a datalist, hr, or option element, then return null.
            if matches!(
                ancestor.local_name(),
                &local_name!("datalist") | &local_name!("hr") | &local_name!("option")
            ) {
                return None;
            }

            // Step 2.2 If ancestor is an optgroup element
            if ancestor.local_name() == &local_name!("optgroup") {
                // Step 2.1 If ancestorOptgroup is not null, then return null.
                if did_see_ancestor_optgroup {
                    return None;
                }

                // Step 2.2 Set ancestorOptgroup to ancestor.
                did_see_ancestor_optgroup = true;
            }

            // Step 2.3 If ancestor is a select, then return ancestor.
            if let Some(select) = DomRoot::downcast::<HTMLSelectElement>(ancestor) {
                return Some(select);
            }
        }

        // Step 3. Return null.
        None
    }

    /// <https://html.spec.whatwg.org/multipage/#maybe-clone-an-option-into-selectedcontent>
    pub(crate) fn maybe_clone_an_option_into_selectedcontent(&self, cx: &mut JSContext) {
        // Step 1. Let select be option's option element nearest ancestor select.
        let select = self.nearest_ancestor_select();

        // Step 2. If all of the following conditions are true:
        // * select is not null;
        // * option's selectedness is true; and
        // * select's enabled selectedcontent is not null,
        // * then run clone an option into a selectedcontent given option and select's enabled selectedcontent.
        if self.selectedness.get() &&
            let Some(selectedcontent) =
                select.and_then(|select| select.get_enabled_selectedcontent())
        {
            self.clone_an_option_into_selectedcontent(cx, &selectedcontent);
        }
    }

    /// <https://html.spec.whatwg.org/multipage/#clone-an-option-into-a-selectedcontent>
    pub(crate) fn clone_an_option_into_selectedcontent(
        &self,
        cx: &mut JSContext,
        selectedcontent: &Element,
    ) {
        // Step 1. Let documentFragment be a new DocumentFragment whose node document is option's node document.
        let document_fragment = DocumentFragment::new(cx, &self.owner_document());

        // Step 2. For each child of option's children:
        for child in self.upcast::<Node>().children() {
            // Step 2.1 Let childClone be the result of running clone given child with subtree set to true.
            let child_clone = Node::clone(cx, &child, None, CloneChildrenFlag::CloneChildren, None);

            // Step 2.2 Append childClone to documentFragment.
            let _ = document_fragment
                .upcast::<Node>()
                .AppendChild(cx, &child_clone);
        }

        // Step 3. Replace all with documentFragment within selectedcontent.
        Node::replace_all(
            cx,
            Some(document_fragment.upcast()),
            selectedcontent.upcast(),
        );
    }

    /// <https://html.spec.whatwg.org/multipage/#update-an-option's-nearest-ancestor-select>
    fn update_nearest_ancestor_selection(
        &self,
        cx: &mut JSContext,
    ) -> Vec<DomRoot<HTMLSelectElement>> {
        // Step 1. Let oldSelect be option's cached nearest ancestor select element.
        let old_select = self.cached_nearest_ancestor_select.get();

        // Step 2. Let newSelect be option's nearest ancestor select.
        let new_select = self.nearest_ancestor_select();

        // Step 3. Set option's cached nearest ancestor select element to newSelect.
        self.cached_nearest_ancestor_select
            .set(new_select.as_deref());

        // Step 4. If oldSelect is newSelect, then return « ».
        if old_select == new_select {
            return Vec::new();
        }

        // Step 5. Let result be « ».
        let mut result = Vec::new();

        // Step 6. For each select of « oldSelect, newSelect »:
        for select in [old_select, new_select] {
            // Step 6.1. If select is null, then continue.
            let Some(select) = select else {
                continue;
            };

            // Step 6.2. Let hasChanged be the result of running the selectedness setting algorithm
            // given select.
            let has_changed = select.selectedness_setting_algorithm(cx.no_gc());

            // This is not specified, but Servo needs to update the cached validity state and shadow
            // tree of select elements when their descendants change.
            select
                .validity_state(cx)
                .perform_validation_and_update(cx, ValidationFlags::all());
            select.update_shadow_tree(cx);

            // Step 6.3. If option's selectedness is true or hasChanged is true, then append select
            // to result.
            if self.Selected() || has_changed {
                result.push(select);
            }
        }

        // Step 7. Return result.
        result
    }

    /// <https://html.spec.whatwg.org/multipage/#ask-for-a-reset>
    fn ask_for_a_reset(&self, cx: &mut JSContext) {
        // Step 1. Let select be option's cached nearest ancestor select element.
        let select = self.cached_nearest_ancestor_select.get();
        // Step 2. If select is null, then return.
        let Some(select) = select else {
            return;
        };
        // Step 3. Run the selectedness setting algorithm given select.
        select.selectedness_setting_algorithm(cx.no_gc());
        // Step 4. Update a select's descendant selectedcontent elements given select.
        select.update_a_selects_descendant_selectedcontent_elements(cx);

        // Note: This is unspecified, but this is where we update the cached validity
        // and shadow tree when things change in this option element.
        select
            .validity_state(cx)
            .perform_validation_and_update(cx, ValidationFlags::all());
        select.update_shadow_tree(cx);
    }

    /// Update the disabled state of this [`HTMLOptionElement`] based on its
    /// disabled attribute and whether or not its owning [`HTMLOptGroupElement`]
    /// is disabled.
    pub(crate) fn update_disabled_state(&self, no_gc: &NoGC) {
        let element = self.upcast::<Element>();
        let disabled = element.has_attribute(&local_name!("disabled")) ||
            self.is_disabled_by_parent_optgroup(no_gc);
        element.set_disabled_state(no_gc, disabled);
        element.set_enabled_state(no_gc, !disabled);
    }

    fn is_disabled_by_parent_optgroup(&self, no_gc: &NoGC) -> bool {
        self.upcast::<Node>()
            .get_parent_node_unrooted(no_gc)
            .and_then(UnrootedDom::downcast::<HTMLOptGroupElement>)
            .is_some_and(|optgroup| optgroup.upcast::<Element>().disabled_state())
    }
}

impl HTMLOptionElementMethods<crate::DomTypeHolder> for HTMLOptionElement {
    /// <https://html.spec.whatwg.org/multipage/#dom-option>
    fn Option(
        cx: &mut JSContext,
        window: &Window,
        proto: Option<HandleObject>,
        text: DOMString,
        value: Option<DOMString>,
        default_selected: bool,
        selected: bool,
    ) -> Fallible<DomRoot<HTMLOptionElement>> {
        let element = Element::create(
            cx,
            QualName::new(None, ns!(html), local_name!("option")),
            None,
            &window.Document(),
            ElementCreator::ScriptCreated,
            CustomElementCreationMode::Synchronous,
            proto,
        );

        let option = DomRoot::downcast::<HTMLOptionElement>(element).unwrap();

        if !text.is_empty() {
            option
                .upcast::<Node>()
                .set_text_content_for_element(cx, Some(text))
        }

        if let Some(val) = value {
            option.SetValue(cx, val)
        }

        option.SetDefaultSelected(cx, default_selected);
        option.set_selectedness(cx, selected);
        option.update_select_validity(cx);
        Ok(option)
    }

    // https://html.spec.whatwg.org/multipage/#dom-option-disabled
    make_bool_getter!(Disabled, "disabled");

    // https://html.spec.whatwg.org/multipage/#dom-option-disabled
    make_bool_setter!(SetDisabled, "disabled");

    /// <https://html.spec.whatwg.org/multipage/#dom-option-text>
    fn Text(&self) -> DOMString {
        let mut content = DOMString::new();

        let mut iterator = self.upcast::<Node>().traverse_preorder(ShadowIncluding::No);
        while let Some(node) = iterator.peek() {
            if let Some(element) = node.downcast::<Element>() {
                let html_script = element.is::<HTMLScriptElement>();
                let svg_script = *element.namespace() == ns!(svg) &&
                    element.local_name() == &local_name!("script");
                if html_script || svg_script {
                    iterator.next_skipping_children();
                    continue;
                }
            }

            if node.is::<Text>() {
                let characterdata = node.downcast::<CharacterData>().unwrap();
                content.push_str(&characterdata.Data().str());
            }

            iterator.next();
        }

        DOMString::from(str_join(split_html_space_chars(&content.str()), " "))
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-option-text>
    fn SetText(&self, cx: &mut JSContext, value: DOMString) {
        self.upcast::<Node>()
            .set_text_content_for_element(cx, Some(value))
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-option-form>
    fn GetForm(&self) -> Option<DomRoot<HTMLFormElement>> {
        self.cached_nearest_ancestor_select()
            .and_then(|s| s.GetForm())
    }

    /// <https://html.spec.whatwg.org/multipage/#attr-option-value>
    fn Value(&self) -> DOMString {
        let element = self.upcast::<Element>();
        let attr = &local_name!("value");
        if element.has_attribute(attr) {
            element.get_string_attribute(attr)
        } else {
            self.Text()
        }
    }

    // https://html.spec.whatwg.org/multipage/#attr-option-value
    make_setter!(SetValue, "value");

    /// <https://html.spec.whatwg.org/multipage/#attr-option-label>
    fn Label(&self) -> DOMString {
        let element = self.upcast::<Element>();
        let attr = &local_name!("label");
        if element.has_attribute(attr) {
            element.get_string_attribute(attr)
        } else {
            self.Text()
        }
    }

    // https://html.spec.whatwg.org/multipage/#attr-option-label
    make_setter!(SetLabel, "label");

    // https://html.spec.whatwg.org/multipage/#dom-option-defaultselected
    make_bool_getter!(DefaultSelected, "selected");

    // https://html.spec.whatwg.org/multipage/#dom-option-defaultselected
    make_bool_setter!(SetDefaultSelected, "selected");

    /// <https://html.spec.whatwg.org/multipage/#dom-option-selected>
    fn Selected(&self) -> bool {
        self.selectedness.get()
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-option-selected>
    fn SetSelected(&self, cx: &mut JSContext, selected: bool) {
        // Step 1. Set this's selectedness to the given value.
        if self.set_selectedness(cx, selected) {
            self.pick_if_selected_in_cached_select(cx);
        }
        // Step 2. Set this's dirtiness to true.
        self.dirtiness.set(true);
        // Step 3. Ask for a reset given this.
        self.ask_for_a_reset(cx);
    }

    /// <https://html.spec.whatwg.org/multipage/#dom-option-index>
    fn Index(&self, cx: &JSContext) -> i32 {
        self.index(cx.no_gc())
    }
}

impl VirtualMethods for HTMLOptionElement {
    fn super_type(&self) -> Option<&dyn VirtualMethods> {
        Some(self.upcast::<HTMLElement>() as &dyn VirtualMethods)
    }

    fn attribute_mutated(
        &self,
        cx: &mut js::context::JSContext,
        attr: AttrRef<'_>,
        mutation: AttributeMutation,
    ) {
        self.super_type()
            .unwrap()
            .attribute_mutated(cx, attr, mutation);
        match *attr.local_name() {
            local_name!("disabled") => {
                self.update_disabled_state(cx.no_gc());
                self.update_select_validity(cx);
            },
            local_name!("selected") => {
                let mut selectedness_changed = false;
                match mutation {
                    AttributeMutation::Set(_) => {
                        // https://html.spec.whatwg.org/multipage/#concept-option-selectedness
                        if !self.dirtiness.get() && !self.selectedness.get() {
                            self.set_selectedness(cx.no_gc(), true);
                            selectedness_changed = true;
                        }
                    },
                    AttributeMutation::Removed => {
                        // https://html.spec.whatwg.org/multipage/#concept-option-selectedness
                        if !self.dirtiness.get() && self.selectedness.get() {
                            self.set_selectedness(cx.no_gc(), false);
                            selectedness_changed = true;
                        }
                    },
                }

                if selectedness_changed {
                    self.pick_if_selected_in_cached_select(cx);
                    self.ask_for_a_reset(cx);
                }
                self.update_select_validity(cx);
            },
            local_name!("label") => {
                // The label of the selected option is displayed inside the select element, so we need to repaint
                // when it changes
                if let Some(select_element) = self.cached_nearest_ancestor_select() {
                    select_element.update_shadow_tree(cx);
                }
            },
            _ => {},
        }
    }

    fn bind_to_tree(&self, cx: &mut JSContext, context: &BindContext) {
        if let Some(super_type) = self.super_type() {
            super_type.bind_to_tree(cx, context);
        }

        self.update_disabled_state(cx.no_gc());

        // TODO: When several selected option elements are added at once, the specification doesn't
        // say which one should win. Firefox chooses the last one and we should do the same here.
        // This should ensure that all selected `<option>` elements outside of the inserted subtree
        // are unselected.
        if let Some(select) = self.nearest_ancestor_select() {
            self.pick_if_selected_in_select(cx, &select);
        }

        self.update_nearest_ancestor_selection(cx);
        self.update_select_validity(cx);
    }

    fn unbind_from_tree(&self, cx: &mut js::context::JSContext, context: &UnbindContext) {
        self.super_type().unwrap().unbind_from_tree(cx, context);

        // Step 1. Let selects be the result of update an option's nearest ancestor select given
        // removedNode.
        let selects = self.update_nearest_ancestor_selection(cx);

        // Step 2. For each select of selects: queue a microtask to update a select's descendant
        // selectedcontent elements given select.
        for select in selects {
            self.global().enqueue_microtask(
                cx,
                Box::new(UpdateSelectedContentMicrotask {
                    select: select.as_traced(),
                }),
            );
        }

        self.update_disabled_state(cx.no_gc());
    }

    fn children_changed(&self, cx: &mut JSContext, mutation: &ChildrenMutation) {
        if let Some(super_type) = self.super_type() {
            super_type.children_changed(cx, mutation);
        }

        // Changing the descendants of a selected option can change it's displayed label
        // if it does not have a label attribute
        if !self
            .upcast::<Element>()
            .has_attribute(&local_name!("label")) &&
            let Some(owner_select) = self.cached_nearest_ancestor_select() &&
            owner_select
                .selected_option(cx.no_gc())
                .is_some_and(|selected_option| *self == **selected_option)
        {
            owner_select.update_shadow_tree(cx);
        }
    }

    /// <https://html.spec.whatwg.org/multipage/#the-option-element:html-element-moving-steps>
    fn moving_steps(&self, cx: &mut JSContext, context: &MoveContext) {
        if let Some(super_type) = self.super_type() {
            super_type.moving_steps(cx, context);
        }

        self.update_disabled_state(cx.no_gc());

        // TODO: When several selected option elements are added at once, the specification doesn't
        // say which one should win. Firefox chooses the last one and we should do the same here.
        // This should ensure that all selected `<option>` elements outside of the moved subtree
        // are unselected.
        if let Some(select) = self.nearest_ancestor_select() {
            self.pick_if_selected_in_select(cx, &select);
        }

        // Step 1. Let selects be the result of update an option's nearest ancestor select given
        // movedNode.
        let selects = self.update_nearest_ancestor_selection(cx);

        // Step 2. For each select of selects: queue a microtask to update a select's descendant
        // selectedcontent elements given select.
        for select in selects {
            self.global().enqueue_microtask(
                cx,
                Box::new(UpdateSelectedContentMicrotask {
                    select: select.as_traced(),
                }),
            );
        }
    }
}

#[derive(JSTraceable, MallocSizeOf)]
#[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
struct UpdateSelectedContentMicrotask {
    select: Dom<HTMLSelectElement>,
}

impl MicrotaskRunnable for UpdateSelectedContentMicrotask {
    fn handler(&self, cx: &mut JSContext) {
        let mut realm = enter_auto_realm(cx, &*self.select);
        let cx = &mut realm;
        self.select
            .update_a_selects_descendant_selectedcontent_elements(cx);
    }
}