1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170

#![doc(html_logo_url = "https://avatars.githubusercontent.com/u/79236386")]
#![doc(html_favicon_url = "https://avatars.githubusercontent.com/u/79236386")]
#![deny(missing_docs)]

//! Dioxus WebSys
//!
//! ## Overview
//! ------------
//! This crate implements a renderer of the Dioxus Virtual DOM for the web browser using WebSys. This web render for
//! Dioxus is one of the more advanced renderers, supporting:
//! - idle work
//! - animations
//! - jank-free rendering
//! - controlled components
//! - hydration
//! - and more.
//!
//! The actual implementation is farily thin, with the heavy lifting happening inside the Dioxus Core crate.
//!
//! To purview the examples, check of the root Dioxus crate - the examples in this crate are mostly meant to provide
//! validation of websys-specific features and not the general use of Dioxus.

use std::rc::Rc;

pub use crate::cfg::Config;
#[cfg(feature = "file_engine")]
pub use crate::file_engine::WebFileEngineExt;
use dioxus_core::VirtualDom;
use futures_util::{pin_mut, select, FutureExt, StreamExt};

mod cfg;
mod dom;

mod event;
pub mod launch;
mod mutations;
pub use event::*;

#[cfg(feature = "eval")]
mod eval;

#[cfg(feature = "file_engine")]
mod file_engine;

#[cfg(all(feature = "hot_reload", debug_assertions))]
mod hot_reload;

#[cfg(feature = "hydrate")]
mod rehydrate;

/// Runs the app as a future that can be scheduled around the main thread.
///
/// Polls futures internal to the VirtualDOM, hence the async nature of this function.
///
/// # Example
///
/// ```ignore, rust
/// let app_fut = dioxus_web::run_with_props(App, RootProps { name: String::from("foo") });
/// wasm_bindgen_futures::spawn_local(app_fut);
/// ```
pub async fn run(virtual_dom: VirtualDom, web_config: Config) {
    tracing::info!("Starting up");

    let mut dom = virtual_dom;

    #[cfg(feature = "eval")]
    dom.in_runtime(eval::init_eval);

    #[cfg(feature = "panic_hook")]
    if web_config.default_panic_hook {
        console_error_panic_hook::set_once();
    }

    #[cfg(all(feature = "hot_reload", debug_assertions))]
    let mut hotreload_rx = hot_reload::init();

    let (tx, mut rx) = futures_channel::mpsc::unbounded();

    let should_hydrate = web_config.hydrate;

    let mut websys_dom = dom::WebsysDom::new(web_config, tx);

    tracing::info!("rebuilding app");

    if should_hydrate {
        #[cfg(feature = "hydrate")]
        {
            dom.rebuild(&mut crate::rehydrate::OnlyWriteTemplates(&mut websys_dom));

            if let Err(err) = websys_dom.rehydrate(&dom) {
                tracing::error!("Rehydration failed. {:?}", err);
                tracing::error!("Rebuild DOM into element from scratch");
                websys_dom.root.set_text_content(None);

                dom.rebuild(&mut websys_dom);

                websys_dom.flush_edits();
            }
        }
    } else {
        dom.rebuild(&mut websys_dom);

        websys_dom.flush_edits();
    }

    // the mutations come back with nothing - we need to actually mount them
    websys_dom.mount();

    loop {
        // if virtual dom has nothing, wait for it to have something before requesting idle time
        // if there is work then this future resolves immediately.
        let (mut res, template) = {
            let work = dom.wait_for_work().fuse();
            pin_mut!(work);

            let mut rx_next = rx.select_next_some();

            #[cfg(all(feature = "hot_reload", debug_assertions))]
            {
                let mut hot_reload_next = hotreload_rx.select_next_some();
                select! {
                    _ = work => (None, None),
                    new_template = hot_reload_next => (None, Some(new_template)),
                    evt = rx_next => (Some(evt), None),
                }
            }

            #[cfg(not(all(feature = "hot_reload", debug_assertions)))]
            select! {
                _ = work => (None, None),
                evt = rx_next => (Some(evt), None),
            }
        };

        if let Some(template) = template {
            dom.replace_template(template);
        }

        // Dequeue all of the events from the channel in send order
        // todo: we should re-order these if possible
        while let Some(evt) = res {
            dom.handle_event(
                evt.name.as_str(),
                Rc::new(evt.data),
                evt.element,
                evt.bubbles,
            );
            res = rx.try_next().transpose().unwrap().ok();
        }

        // Todo: This is currently disabled because it has a negative impact on response times for events but it could be re-enabled for tasks
        // Jank free rendering
        //
        // 1. wait for the browser to give us "idle" time
        // 2. During idle time, diff the dom
        // 3. Stop diffing if the deadline is exceded
        // 4. Wait for the animation frame to patch the dom

        // wait for the mainthread to schedule us in
        // let deadline = work_loop.wait_for_idle_time().await;

        // run the virtualdom work phase until the frame deadline is reached
        dom.render_immediate(&mut websys_dom);

        // wait for the animation frame to fire so we can apply our changes
        // work_loop.wait_for_raf().await;

        websys_dom.flush_edits();
    }
}