dioxus-mirror/packages/web/src/dom.rs

//! Implementation of a renderer for Dioxus on the web.
//!
//! Oustanding todos:
//! - Removing event listeners (delegation)
//! - Passive event listeners
//! - no-op event listener patch for safari
//! - tests to ensure dyn_into works for various event types.
//! - Partial delegation?>

use dioxus_core::{
    events::{SyntheticEvent, UserEvent},
    mutations::NodeRefMutation,
    scheduler::SchedulerMsg,
    DomEdit, ElementId, ScopeId,
};
use fxhash::FxHashMap;
use std::{fmt::Debug, rc::Rc, sync::Arc};
use wasm_bindgen::{closure::Closure, JsCast};
use web_sys::{
    Attr, CssStyleDeclaration, Document, Element, Event, HtmlElement, HtmlInputElement,
    HtmlOptionElement, HtmlTextAreaElement, Node, NodeList,
};

use crate::{nodeslab::NodeSlab, WebConfig};

pub struct WebsysDom {
    stack: Stack,

    /// A map from ElementID (index) to Node
    nodes: NodeSlab,

    document: Document,

    root: Element,

    sender_callback: Rc<dyn Fn(SchedulerMsg)>,

    // map of listener types to number of those listeners
    // This is roughly a delegater
    // TODO: check how infero delegates its events - some are more performant
    listeners: FxHashMap<&'static str, ListenerEntry>,

    // We need to make sure to add comments between text nodes
    // We ensure that the text siblings are patched by preventing the browser from merging
    // neighboring text nodes. Originally inspired by some of React's work from 2016.
    //  -> https://reactjs.org/blog/2016/04/07/react-v15.html#major-changes
    //  -> https://github.com/facebook/react/pull/5753
    last_node_was_text: bool,
}

type ListenerEntry = (usize, Closure<dyn FnMut(&Event)>);

impl WebsysDom {
    pub fn new(root: Element, cfg: WebConfig, sender_callback: Rc<dyn Fn(SchedulerMsg)>) -> Self {
        let document = load_document();

        let mut nodes = NodeSlab::new(2000);
        let mut listeners = FxHashMap::default();

        // re-hydrate the page - only supports one virtualdom per page
        if cfg.hydrate {
            // Load all the elements into the arena
            let node_list: NodeList = document.query_selector_all("dio_el").unwrap();
            let len = node_list.length() as usize;

            for x in 0..len {
                let node: Node = node_list.get(x as u32).unwrap();
                let el: &Element = node.dyn_ref::<Element>().unwrap();
                let id: String = el.get_attribute("dio_el").unwrap();
                let id = id.parse::<usize>().unwrap();
                nodes[id] = Some(node);
            }

            // Load all the event listeners into our listener register
            // TODO
        }

        let mut stack = Stack::with_capacity(10);
        let root_node = root.clone().dyn_into::<Node>().unwrap();
        stack.push(root_node);

        Self {
            stack,
            nodes,
            listeners,
            document,
            sender_callback,
            root,
            last_node_was_text: false,
        }
    }

    pub fn apply_refs(&mut self, refs: &[NodeRefMutation]) {
        for item in refs {
            if let Some(bla) = &item.element {
                let node = self.nodes[item.element_id.as_u64() as usize]
                    .as_ref()
                    .unwrap()
                    .clone();
                bla.set(Box::new(node)).unwrap();
            }
        }
    }

    pub fn process_edits(&mut self, edits: &mut Vec<DomEdit>) {
        for edit in edits.drain(..) {
            match edit {
                DomEdit::PushRoot { id: root } => self.push(root),
                DomEdit::PopRoot => self.pop(),
                DomEdit::AppendChildren { many } => self.append_children(many),
                DomEdit::ReplaceWith { m, root } => self.replace_with(m, root),
                DomEdit::Remove { root } => self.remove(root),
                DomEdit::RemoveAllChildren => self.remove_all_children(),
                DomEdit::CreateTextNode { text, id } => self.create_text_node(text, id),
                DomEdit::CreateElement { tag, id } => self.create_element(tag, None, id),
                DomEdit::CreateElementNs { tag, id, ns } => self.create_element(tag, Some(ns), id),
                DomEdit::CreatePlaceholder { id } => self.create_placeholder(id),
                DomEdit::NewEventListener {
                    event_name,
                    scope,
                    mounted_node_id,
                } => self.new_event_listener(event_name, scope, mounted_node_id),

                DomEdit::RemoveEventListener { event } => todo!(),

                DomEdit::SetText { text } => self.set_text(text),
                DomEdit::SetAttribute { field, value, ns } => self.set_attribute(field, value, ns),
                DomEdit::RemoveAttribute { name } => self.remove_attribute(name),

                DomEdit::InsertAfter { n, root } => self.insert_after(n, root),
                DomEdit::InsertBefore { n, root } => self.insert_before(n, root),
            }
        }
    }
    fn push(&mut self, root: u64) {
        let key = root as usize;
        let domnode = &self.nodes[key];

        let real_node: Node = match domnode {
            Some(n) => n.clone(),
            None => todo!(),
        };

        self.stack.push(real_node);
    }

    // drop the node off the stack
    fn pop(&mut self) {
        self.stack.pop();
    }

    fn append_children(&mut self, many: u32) {
        let root: Node = self
            .stack
            .list
            .get(self.stack.list.len() - (1 + many as usize))
            .unwrap()
            .clone();

        for child in self
            .stack
            .list
            .drain((self.stack.list.len() - many as usize)..)
        {
            if child.dyn_ref::<web_sys::Text>().is_some() {
                if self.last_node_was_text {
                    let comment_node = self
                        .document
                        .create_comment("dioxus")
                        .dyn_into::<Node>()
                        .unwrap();
                    root.append_child(&comment_node).unwrap();
                }
                self.last_node_was_text = true;
            } else {
                self.last_node_was_text = false;
            }
            root.append_child(&child).unwrap();
        }
    }

    fn replace_with(&mut self, m: u32, root: u64) {
        let old = self.nodes[root as usize].as_ref().unwrap();

        let arr: js_sys::Array = self
            .stack
            .list
            .drain((self.stack.list.len() - m as usize)..)
            .collect();

        if let Some(el) = old.dyn_ref::<Element>() {
            el.replace_with_with_node(&arr).unwrap();
        } else if let Some(el) = old.dyn_ref::<web_sys::CharacterData>() {
            el.replace_with_with_node(&arr).unwrap();
        } else if let Some(el) = old.dyn_ref::<web_sys::DocumentType>() {
            el.replace_with_with_node(&arr).unwrap();
        }
    }

    fn remove(&mut self, root: u64) {
        let node = self.nodes[root as usize].as_ref().unwrap();
        if let Some(element) = node.dyn_ref::<Element>() {
            element.remove();
        } else {
            if let Some(parent) = node.parent_node() {
                parent.remove_child(&node).unwrap();
            }
        }
    }

    fn remove_all_children(&mut self) {
        todo!()
    }

    fn create_placeholder(&mut self, id: u64) {
        self.create_element("pre", None, id);
        self.set_attribute("hidden", "", None);
    }

    fn create_text_node(&mut self, text: &str, id: u64) {
        let textnode = self
            .document
            .create_text_node(text)
            .dyn_into::<Node>()
            .unwrap();

        self.stack.push(textnode.clone());

        self.nodes[(id as usize)] = Some(textnode);
    }

    fn create_element(&mut self, tag: &str, ns: Option<&'static str>, id: u64) {
        let tag = wasm_bindgen::intern(tag);

        let el = match ns {
            Some(ns) => self
                .document
                .create_element_ns(Some(ns), tag)
                .unwrap()
                .dyn_into::<Node>()
                .unwrap(),
            None => self
                .document
                .create_element(tag)
                .unwrap()
                .dyn_into::<Node>()
                .unwrap(),
        };

        self.stack.push(el.clone());
        self.nodes[(id as usize)] = Some(el);
    }

    fn new_event_listener(&mut self, event: &'static str, scope: ScopeId, real_id: u64) {
        let event = wasm_bindgen::intern(event);

        // attach the correct attributes to the element
        // these will be used by accessing the event's target
        // This ensures we only ever have one handler attached to the root, but decide
        // dynamically when we want to call a listener.

        let el = self.stack.top();

        let el = el
            .dyn_ref::<Element>()
            .expect(&format!("not an element: {:?}", el));

        // let scope_id = scope.data().as_ffi();
        let scope_id = scope.0 as u64;

        el.set_attribute(
            &format!("dioxus-event-{}", event),
            &format!("{}.{}", scope_id, real_id),
        )
        .unwrap();

        // el.set_attribute(&format!("dioxus-event"), &format!("{}", event))
        //     .unwrap();

        // Register the callback to decode

        if let Some(entry) = self.listeners.get_mut(event) {
            entry.0 += 1;
        } else {
            let trigger = self.sender_callback.clone();

            let handler = Closure::wrap(Box::new(move |event: &web_sys::Event| {
                // "Result" cannot be received from JS
                // Instead, we just build and immediately execute a closure that returns result
                match decode_trigger(event) {
                    Ok(synthetic_event) => trigger.as_ref()(SchedulerMsg::UiEvent(synthetic_event)),
                    Err(e) => log::error!("Error decoding Dioxus event attribute. {:#?}", e),
                };
            }) as Box<dyn FnMut(&Event)>);

            self.root
                .add_event_listener_with_callback(event, (&handler).as_ref().unchecked_ref())
                .unwrap();

            // Increment the listeners
            self.listeners.insert(event.into(), (1, handler));
        }
    }

    fn remove_event_listener(&mut self, event: &str) {
        todo!()
    }

    fn set_text(&mut self, text: &str) {
        self.stack.top().set_text_content(Some(text))
    }

    fn set_attribute(&mut self, name: &str, value: &str, ns: Option<&str>) {
        let node = self.stack.top();
        if ns == Some("style") {
            if let Some(el) = node.dyn_ref::<Element>() {
                let el = el.dyn_ref::<HtmlElement>().unwrap();
                let style_dc: CssStyleDeclaration = el.style();
                style_dc.set_property(name, value).unwrap();
            }
        } else {
            let fallback = || {
                let el = node.dyn_ref::<Element>().unwrap();
                el.set_attribute(name, value).unwrap()
            };
            match name {
                "value" => {
                    if let Some(input) = node.dyn_ref::<HtmlInputElement>() {
                        /*
                        if the attribute being set is the same as the value of the input, then don't bother setting it.
                        This is used in controlled components to keep the cursor in the right spot.

                        this logic should be moved into the virtualdom since we have the notion of "volatile"
                        */
                        if input.value() != value {
                            input.set_value(value);
                        }
                    } else if let Some(node) = node.dyn_ref::<HtmlTextAreaElement>() {
                        if name == "value" {
                            node.set_value(value);
                        }
                    } else {
                        fallback();
                    }
                }
                "checked" => {
                    if let Some(input) = node.dyn_ref::<HtmlInputElement>() {
                        input.set_checked(true);
                    } else {
                        fallback();
                    }
                }
                "selected" => {
                    if let Some(node) = node.dyn_ref::<HtmlOptionElement>() {
                        node.set_selected(true);
                    } else {
                        fallback();
                    }
                }
                _ => fallback(),
            }
        }
    }

    fn remove_attribute(&mut self, name: &str) {
        let node = self.stack.top();
        if let Some(node) = node.dyn_ref::<web_sys::Element>() {
            node.remove_attribute(name).unwrap();
        }
        if let Some(node) = node.dyn_ref::<HtmlInputElement>() {
            // Some attributes are "volatile" and don't work through `removeAttribute`.
            if name == "value" {
                node.set_value("");
            }
            if name == "checked" {
                node.set_checked(false);
            }
        }

        if let Some(node) = node.dyn_ref::<HtmlOptionElement>() {
            if name == "selected" {
                node.set_selected(true);
            }
        }
    }

    fn insert_after(&mut self, n: u32, root: u64) {
        let old = self.nodes[root as usize].as_ref().unwrap();

        let arr: js_sys::Array = self
            .stack
            .list
            .drain((self.stack.list.len() - n as usize)..)
            .collect();

        if let Some(el) = old.dyn_ref::<Element>() {
            el.after_with_node(&arr).unwrap();
        } else if let Some(el) = old.dyn_ref::<web_sys::CharacterData>() {
            el.after_with_node(&arr).unwrap();
        } else if let Some(el) = old.dyn_ref::<web_sys::DocumentType>() {
            el.after_with_node(&arr).unwrap();
        }
    }

    fn insert_before(&mut self, n: u32, root: u64) {
        let after = self.nodes[root as usize].as_ref().unwrap();

        if n == 1 {
            let before = self.stack.pop();

            after
                .parent_node()
                .unwrap()
                .insert_before(&before, Some(&after))
                .unwrap();

            after.insert_before(&before, None).unwrap();
        } else {
            let arr: js_sys::Array = self
                .stack
                .list
                .drain((self.stack.list.len() - n as usize)..)
                .collect();

            if let Some(el) = after.dyn_ref::<Element>() {
                el.before_with_node(&arr).unwrap();
            } else if let Some(el) = after.dyn_ref::<web_sys::CharacterData>() {
                el.before_with_node(&arr).unwrap();
            } else if let Some(el) = after.dyn_ref::<web_sys::DocumentType>() {
                el.before_with_node(&arr).unwrap();
            }
        }
    }
}

#[derive(Debug, Default)]
struct Stack {
    list: Vec<Node>,
}

impl Stack {
    #[inline]
    fn with_capacity(cap: usize) -> Self {
        Stack {
            list: Vec::with_capacity(cap),
        }
    }

    #[inline]
    fn push(&mut self, node: Node) {
        self.list.push(node);
    }

    #[inline]
    fn pop(&mut self) -> Node {
        self.list.pop().unwrap()
    }

    fn top(&self) -> &Node {
        match self.list.last() {
            Some(a) => a,
            None => panic!("Called 'top' of an empty stack, make sure to push the root first"),
        }
    }
}

// todo: some of these events are being casted to the wrong event type.
// We need tests that simulate clicks/etc and make sure every event type works.
fn virtual_event_from_websys_event(event: web_sys::Event) -> SyntheticEvent {
    use crate::events::*;
    use dioxus_core::events::on::*;
    match event.type_().as_str() {
        "copy" | "cut" | "paste" => {
            SyntheticEvent::ClipboardEvent(ClipboardEvent(Arc::new(WebsysClipboardEvent(event))))
        }
        "compositionend" | "compositionstart" | "compositionupdate" => {
            let evt: web_sys::CompositionEvent = event.dyn_into().unwrap();
            SyntheticEvent::CompositionEvent(CompositionEvent(Arc::new(WebsysCompositionEvent(
                evt,
            ))))
        }
        "keydown" | "keypress" | "keyup" => {
            let evt: web_sys::KeyboardEvent = event.dyn_into().unwrap();
            SyntheticEvent::KeyboardEvent(KeyboardEvent(Arc::new(WebsysKeyboardEvent(evt))))
        }
        "focus" | "blur" => {
            let evt: web_sys::FocusEvent = event.dyn_into().unwrap();
            SyntheticEvent::FocusEvent(FocusEvent(Arc::new(WebsysFocusEvent(evt))))
        }
        "change" => {
            let evt = event.dyn_into().unwrap();
            SyntheticEvent::GenericEvent(GenericEvent(Arc::new(WebsysGenericUiEvent(evt))))
        }
        "input" | "invalid" | "reset" | "submit" => {
            let evt: web_sys::Event = event.dyn_into().unwrap();
            SyntheticEvent::FormEvent(FormEvent(Arc::new(WebsysFormEvent(evt))))
        }
        "click" | "contextmenu" | "doubleclick" | "drag" | "dragend" | "dragenter" | "dragexit"
        | "dragleave" | "dragover" | "dragstart" | "drop" | "mousedown" | "mouseenter"
        | "mouseleave" | "mousemove" | "mouseout" | "mouseover" | "mouseup" => {
            let evt: web_sys::MouseEvent = event.dyn_into().unwrap();
            SyntheticEvent::MouseEvent(MouseEvent(Arc::new(WebsysMouseEvent(evt))))
        }
        "pointerdown" | "pointermove" | "pointerup" | "pointercancel" | "gotpointercapture"
        | "lostpointercapture" | "pointerenter" | "pointerleave" | "pointerover" | "pointerout" => {
            let evt: web_sys::PointerEvent = event.dyn_into().unwrap();
            SyntheticEvent::PointerEvent(PointerEvent(Arc::new(WebsysPointerEvent(evt))))
        }
        "select" => {
            let evt: web_sys::UiEvent = event.dyn_into().unwrap();
            SyntheticEvent::SelectionEvent(SelectionEvent(Arc::new(WebsysGenericUiEvent(evt))))
        }
        "touchcancel" | "touchend" | "touchmove" | "touchstart" => {
            let evt: web_sys::TouchEvent = event.dyn_into().unwrap();
            SyntheticEvent::TouchEvent(TouchEvent(Arc::new(WebsysTouchEvent(evt))))
        }
        "scroll" => {
            let evt: web_sys::UiEvent = event.dyn_into().unwrap();
            SyntheticEvent::GenericEvent(GenericEvent(Arc::new(WebsysGenericUiEvent(evt))))
        }
        "wheel" => {
            let evt: web_sys::WheelEvent = event.dyn_into().unwrap();
            SyntheticEvent::WheelEvent(WheelEvent(Arc::new(WebsysWheelEvent(evt))))
        }
        "animationstart" | "animationend" | "animationiteration" => {
            let evt: web_sys::AnimationEvent = event.dyn_into().unwrap();
            SyntheticEvent::AnimationEvent(AnimationEvent(Arc::new(WebsysAnimationEvent(evt))))
        }
        "transitionend" => {
            let evt: web_sys::TransitionEvent = event.dyn_into().unwrap();
            SyntheticEvent::TransitionEvent(TransitionEvent(Arc::new(WebsysTransitionEvent(evt))))
        }
        "abort" | "canplay" | "canplaythrough" | "durationchange" | "emptied" | "encrypted"
        | "ended" | "error" | "loadeddata" | "loadedmetadata" | "loadstart" | "pause" | "play"
        | "playing" | "progress" | "ratechange" | "seeked" | "seeking" | "stalled" | "suspend"
        | "timeupdate" | "volumechange" | "waiting" => {
            let evt: web_sys::UiEvent = event.dyn_into().unwrap();
            SyntheticEvent::MediaEvent(MediaEvent(Arc::new(WebsysMediaEvent(evt))))
        }
        "toggle" => {
            let evt: web_sys::UiEvent = event.dyn_into().unwrap();
            SyntheticEvent::ToggleEvent(ToggleEvent(Arc::new(WebsysToggleEvent(evt))))
        }
        _ => {
            let evt: web_sys::UiEvent = event.dyn_into().unwrap();
            SyntheticEvent::GenericEvent(GenericEvent(Arc::new(WebsysGenericUiEvent(evt))))
        }
    }
}

/// This function decodes a websys event and produces an EventTrigger
/// With the websys implementation, we attach a unique key to the nodes
fn decode_trigger(event: &web_sys::Event) -> anyhow::Result<UserEvent> {
    let target = event
        .target()
        .expect("missing target")
        .dyn_into::<Element>()
        .expect("not a valid element");

    let typ = event.type_();

    // TODO: clean this up
    if cfg!(debug_assertions) {
        let attrs = target.attributes();
        for x in 0..attrs.length() {
            let attr: Attr = attrs.item(x).unwrap();
            // log::debug!("attrs include: {:#?}, {:#?}", attr.name(), attr.value());
        }
    }

    use anyhow::Context;

    // The error handling here is not very descriptive and needs to be replaced with a zero-cost error system
    let val: String = target
        .get_attribute(&format!("dioxus-event-{}", typ))
        .context(format!("wrong format - received {:#?}", typ))?;

    let mut fields = val.splitn(3, ".");

    let gi_id = fields
        .next()
        .and_then(|f| f.parse::<u64>().ok())
        .context("failed to parse gi id")?;

    let real_id = fields
        .next()
        .and_then(|raw_id| raw_id.parse::<u64>().ok())
        .context("failed to parse real id")?;

    let triggered_scope = gi_id;

    Ok(UserEvent {
        name: event_name_from_typ(&typ),
        event: virtual_event_from_websys_event(event.clone()),
        mounted_dom_id: Some(ElementId(real_id as usize)),
        scope: ScopeId(triggered_scope as usize),
    })
}

pub(crate) fn load_document() -> Document {
    web_sys::window()
        .expect("should have access to the Window")
        .document()
        .expect("should have access to the Document")
}

fn event_name_from_typ(typ: &str) -> &'static str {
    match typ {
        "copy" => "copy",
        "cut" => "cut",
        "paste" => "paste",
        "compositionend" => "compositionend",
        "compositionstart" => "compositionstart",
        "compositionupdate" => "compositionupdate",
        "keydown" => "keydown",
        "keypress" => "keypress",
        "keyup" => "keyup",
        "focus" => "focus",
        "blur" => "blur",
        "change" => "change",
        "input" => "input",
        "invalid" => "invalid",
        "reset" => "reset",
        "submit" => "submit",
        "click" => "click",
        "contextmenu" => "contextmenu",
        "doubleclick" => "doubleclick",
        "drag" => "drag",
        "dragend" => "dragend",
        "dragenter" => "dragenter",
        "dragexit" => "dragexit",
        "dragleave" => "dragleave",
        "dragover" => "dragover",
        "dragstart" => "dragstart",
        "drop" => "drop",
        "mousedown" => "mousedown",
        "mouseenter" => "mouseenter",
        "mouseleave" => "mouseleave",
        "mousemove" => "mousemove",
        "mouseout" => "mouseout",
        "mouseover" => "mouseover",
        "mouseup" => "mouseup",
        "pointerdown" => "pointerdown",
        "pointermove" => "pointermove",
        "pointerup" => "pointerup",
        "pointercancel" => "pointercancel",
        "gotpointercapture" => "gotpointercapture",
        "lostpointercapture" => "lostpointercapture",
        "pointerenter" => "pointerenter",
        "pointerleave" => "pointerleave",
        "pointerover" => "pointerover",
        "pointerout" => "pointerout",
        "select" => "select",
        "touchcancel" => "touchcancel",
        "touchend" => "touchend",
        "touchmove" => "touchmove",
        "touchstart" => "touchstart",
        "scroll" => "scroll",
        "wheel" => "wheel",
        "animationstart" => "animationstart",
        "animationend" => "animationend",
        "animationiteration" => "animationiteration",
        "transitionend" => "transitionend",
        "abort" => "abort",
        "canplay" => "canplay",
        "canplaythrough" => "canplaythrough",
        "durationchange" => "durationchange",
        "emptied" => "emptied",
        "encrypted" => "encrypted",
        "ended" => "ended",
        "error" => "error",
        "loadeddata" => "loadeddata",
        "loadedmetadata" => "loadedmetadata",
        "loadstart" => "loadstart",
        "pause" => "pause",
        "play" => "play",
        "playing" => "playing",
        "progress" => "progress",
        "ratechange" => "ratechange",
        "seeked" => "seeked",
        "seeking" => "seeking",
        "stalled" => "stalled",
        "suspend" => "suspend",
        "timeupdate" => "timeupdate",
        "volumechange" => "volumechange",
        "waiting" => "waiting",
        "toggle" => "toggle",
        _ => {
            panic!("unsupported event type")
        }
    }
}