//! Dioxus WebSys
//! --------------
//! This crate implements a renderer of the Dioxus Virtual DOM for the web browser.
//!
//! While it is possible to render a single component directly, it is not possible to render component trees. For these,
//! an external renderer is needed to progress the component lifecycles. The `WebsysRenderer` shows how to use the Virtual DOM
//! API to progress these lifecycle events to generate a fully-mounted Virtual DOM instance which can be renderer in the
//! `render` method.
//!
//! ```ignore
//! fn main() {
//! let renderer = WebsysRenderer::<()>::new(|_| html! {
"Hello world"
});
//! let output = renderer.render();
//! assert_eq!(output, "
Hello World
");
//! }
//! ```
//!
//! The `WebsysRenderer` is particularly useful when needing to cache a Virtual DOM in between requests
use web_sys::{window, Document, Element, Event, Node};
use dioxus::prelude::VElement;
// use dioxus::{patch::Patch, prelude::VText};
// use dioxus::{patch::Patch, prelude::VText};
pub use dioxus_core as dioxus;
use dioxus_core::{
events::EventTrigger,
prelude::{bumpalo::Bump, html, DiffMachine, VNode, VirtualDom, FC},
};
use futures::{channel::mpsc, future, SinkExt, StreamExt};
use mpsc::UnboundedSender;
pub mod interpreter;
use interpreter::PatchMachine;
/// The `WebsysRenderer` provides a way of rendering a Dioxus Virtual DOM to the browser's DOM.
/// Under the hood, we leverage WebSys and interact directly with the DOM
///
pub struct WebsysRenderer {
internal_dom: VirtualDom,
}
impl WebsysRenderer {
/// Create a new instance of the Dioxus Virtual Dom with no properties for the root component.
///
/// This means that the root component must either consumes its own context, or statics are used to generate the page.
/// The root component can access things like routing in its context.
pub fn new(root: FC<()>) -> Self {
Self::new_with_props(root, ())
}
/// Create a new text-renderer instance from a functional component root.
/// Automatically progresses the creation of the VNode tree to completion.
///
/// A VDom is automatically created. If you want more granular control of the VDom, use `from_vdom`
pub fn new_with_props(root: FC, root_props: T) -> Self {
Self::from_vdom(VirtualDom::new_with_props(root, root_props))
}
/// Create a new text renderer from an existing Virtual DOM.
/// This will progress the existing VDom's events to completion.
pub fn from_vdom(dom: VirtualDom) -> Self {
Self { internal_dom: dom }
}
/// Run the renderer, progressing any events that crop up
/// Yield on event handlers
/// If the dom errors out, self is consumed and the dom is torn down
pub async fn run(self) -> dioxus_core::error::Result<()> {
let WebsysRenderer { mut internal_dom } = self;
// Progress the mount of the root component
internal_dom
.progress()
.expect("Progressing the root failed :(");
// set up the channels to connect listeners to the event loop
let (sender, mut receiver) = mpsc::unbounded::();
// Iterate through the nodes, attaching the closure and sender to the listener
// {
// let mut remote_sender = sender.clone();
// let listener = move || {
// let event = EventTrigger::new();
// wasm_bindgen_futures::spawn_local(async move {
// remote_sender
// .send(event)
// .await
// .expect("Updating receiver failed");
// })
// };
// }
// Event loop waits for the receiver to finish up
// TODO! Connect the sender to the virtual dom's suspense system
// Suspense is basically an external event that can force renders to specific nodes
while let Some(event) = receiver.next().await {
// event is triggered
// relevant listeners are ran
// internal state is modified, components are tagged for changes
match internal_dom.progress_with_event(event).await {
Err(_) => {}
Ok(_) => {} // Ok(_) => render_diffs(),
}
// waiting for next event to arrive from the external triggers
}
Ok(())
}
pub fn simple_render(tree: impl for<'a> Fn(&'a Bump) -> VNode<'a>) {
let bump = Bump::new();
// Choose the body to render the app into
let window = web_sys::window().expect("should have access to the Window");
let document = window
.document()
.expect("should have access to the Document");
let body = document.body().unwrap();
// Build a dummy div
let container: &Element = body.as_ref();
container.set_inner_html("");
container
.append_child(
document
.create_element("div")
.expect("should create element OK")
.as_ref(),
)
.expect("should append child OK");
// Create the old dom and the new dom
// The old is just an empty div, like the one we made above
let old = html! {
}(&bump);
let new = tree(&bump);
// Build a machine that diffs doms
let mut diff_machine = DiffMachine::new(&bump);
diff_machine.diff_node(&old, &new);
// Build a machine that patches doms
// In practice, the diff machine might be on a different computer, sending us patches
let mut patch_machine = PatchMachine::new(body.clone().into());
// need to make sure we push the root node onto the stack before trying to run anything
// this provides an entrance for the diffing machine to do its work
// Here, we grab the div out of the container (the body) to connect with the dummy div we made above
// This is because we don't support fragments (yet)
let root_node = container.first_child().unwrap();
patch_machine.stack.push(root_node);
// Consume the diff machine, generating the patch list
for patch in diff_machine.consume() {
patch_machine.handle_edit(&patch);
log::info!("Patch is {:?}", patch);
}
}
pub fn complex_render(
tree1: impl for<'a> Fn(&'a Bump) -> VNode<'a>,
tree2: impl for<'a> Fn(&'a Bump) -> VNode<'a>,
) {
let bump = Bump::new();
let old = tree1(&bump);
let new = tree2(&bump);
let mut machine = DiffMachine::new(&bump);
machine.diff_node(&old, &new);
for patch in machine.consume() {
println!("Patch is {:?}", patch);
}
}
}
#[cfg(test)]
mod tests {
use std::env;
use super::*;
use dioxus_core as dioxus;
use dioxus_core::prelude::html;
#[test]
fn simple_patch() {
env::set_var("RUST_LOG", "trace");
pretty_env_logger::init();
log::info!("Hello!");
let renderer = WebsysRenderer::simple_render(html! {