Markerless placeholders/Portals/Multiwindow/const builder/optimized templates

[ealmloff]

Changes

• Removes all markers and placeholders from fullstack and core
• Templates are represented at the core level instead of leaking into renderers
• Templates are reworked into a flat structure that is easier to work with in const code
• RSX lowers to a const builder api which fully supports templates
• Html elements are fully trait based and take the exact same path for elements and components
• You can define html elements in user code
• Portals/multirenderer support via a renderer id + routing

Placeholderless

Currently we use comment nodes in several places at runtime and in hydration:

1. To represent Placeholder nodes at runtime
2. To represent empty lists
3. To surround text nodes for hydration

This PR removes all of those in favor of keeping track of the position of nodes relative to an anchor. This lets us:

1. Properly render element that interpret children as text like textarea (Fixes Textarea with placeholder child renders <!--placeholder8--> when first loaded in fullstack #5548)
2. Drop the different between ssr prerendering and rendering since all of that data is now interpreted at runtime

Templates and const builders

This PR introduces a const builder api for vnodes which builds up a cons list-style template in the type system at the same time as the dynamic values. Since the builder only builds up deep trees of &'static Node, we can keep the work to condense the template into a more runtime usable flat form into a single method where &mut ConstVec is usable. This helps to keep down compile times

#[component]
fn Dashboard(#[props(into)] title: String, metrics: &'static [Metric]) -> Element {
    Ok(html::main()
        .onclick(|event| println!("{event:?}"))
        .class("dashboard")
        .child((
            Header.builder().title(title).total(metrics.len()).build(),
            html::section().class("metric-grid").child(
                metrics
                    .iter()
                    .copied()
                    .map(|metric| MetricCard.builder().metric(metric).build()),
            ),
            html::footer()
                .class("note")
                .child("Created with typed HTML builders and component props builders."),
        ))
        .into_vnode())
}

Html extensions

Html elements are no longer namespaced in dioxus_elements and are now trait based which makes them easy to define from user code. We expose a macro to define them which works for the builder api rsx now expands to:

use dioxus::prelude::*;

dioxus::html::define_elements! {
    #[element(name = "analytics-panel")]
    analyticsPanel {
        metric,
        #[attr(name = "data-region")]
        region,
    }
}

fn main() {
    dioxus::launch(app);
}

fn app() -> Element {
    let selected_metric = "conversion-rate";

    rsx! {
        analyticsPanel {
            class: "metric-card",
            metric: selected_metric,
            region: "north-america",
            h2 { "Revenue" }
            p { "Custom elements can still use regular HTML children." }
        }
    }
}

Warning

Since html elements are no longer name spaced, there are some breaking changes around what items can be in scope when you use an element. Eg. you need to use html::main {} instead of main {} to differentiate between the main function in your code and the main element builder in html

Portal support

Core now supports a render id which scopes elementids and events to a specific renderer. This makes it possible to support many desktop windows in the same runtime with shared context, and signals.

TODO:

• Round trip fuzzing with a mock renderer using mutatis
• Make sure the docsite renders correctly
• Make sure the component library renders correctly
• Make sure hotreloading still works
• Playwright tests passing
• Update most tests to use an oracle renderer to assert the output structure is correct instead of asserting the ops themselves

Stacked on #5571, #5633, #5634

Closes #628
Closes #5548
Closes #4019
Closes #5181
Closes #2467
Closes #1627
Closes #2040