weft_web

pub fn animation_loop(f: impl FnMut(f64) + 'static) -> AnimationHandle

Call f(timestamp_ms) every animation frame until stopped.

pub fn attribute_changes(current: &[(String, String)], desired: &[(String, String)]) -> (Vec<String>, Vec<(String, String)>)

Attribute names to remove and pairs to set to turn current into desired (host-internal attributes are left alone).

pub fn color_uniforms(colors: &[Color]) -> [f32; 12]

u_color[4] uniform data, cycling through the given colors.

pub fn create_node(document: &Document, node: &VNode) -> Result<Node, JsValue>

Create the DOM for a virtual node (graphics surfaces get a wrapper, canvas and proxies; drawing happens in the host).

pub fn current_path() -> String

The current route path ("/post/hello").

pub fn device_pixel_size(w: f32, h: f32, dpr: f64) -> (u32, u32)

Backing-store size of a canvas for a CSS size and device pixel ratio.

pub fn embed_asset(url: &str, bytes: &'static [u8])

Build an asset into the app: scenes asking for url get bytes without fetching. For files made at build time, so they show at once:

weft::web::embed_asset("/models/chair.wmodel", include_bytes!("../public/models/chair.wmodel"));

pub fn execute(ctx: &CanvasRenderingContext2d, commands: &[DrawCommand])

Run each command against ctx.

pub async fn fetch(req: Request) -> Result<Response, Error>

Send a request with fetch.

pub fn focus(element: &Element)

Focus an element (e.g. from an event handler).

pub fn focus_paths(tree: &[VNode]) -> Vec<Vec<usize>>

Paths of elements with a truthy focus attribute (declarative focus).

pub fn graphics_paths(tree: &[VNode]) -> Vec<(Vec<usize>, &VElement)>

Every graphics surface in the tree, with its path, in document order.

pub fn graphics_prefix(tree: &[VNode], path: &[usize]) -> Option<Vec<usize>>

The path of the graphics surface that is, or contains, path.

pub fn handles_link(c: LinkClick<'_>) -> bool

Whether the app shows a link's page itself rather than letting the browser load it: a plain click with the main button on a link without target or download, to a page of this origin the app has a route for, that isn't a jump within the current page.

pub fn hash_route() -> Signal<String>

A signal holding the current location.hash (e.g. "#/post/hello"), updated on hashchange. Pair with weft_core::router::Router.

pub fn input_value_text(input_type: &str, checked: bool, value: &str) -> String

The Event::value reported for an input element.

pub fn install_base_css(document: &Document) -> Result<(), JsValue>

Add Weft's base stylesheet to <head> (once).

pub fn install_panic_hook()

Route Rust panics to console.error.

pub fn is_activation_key(key: &str) -> bool

Keys that activate a focused button-like proxy.

pub fn load<F, E>(resource: &Resource, f: F) where F: Future<Output = Result<Value, E>> + 'static, E: Display + 'static

Load f's result into resource (marking it loading meanwhile).

pub fn location_path() -> String

The page's own path (location.pathname, e.g. "/about/"), for sites with one prerendered page per path.

pub fn location_query(name: &str) -> Option<String>

A value in the page's query string (?s=asia → location_query("s") is Some("asia")), decoded.

pub fn mesh_key(p: &Primitive) -> String

Cache key for a primitive's GPU mesh.

pub fn modal_path(tree: &[VNode]) -> Option<Vec<usize>>

The last (topmost) element with aria-modal="true".

pub fn mount(selector: &str, root: Component, registry: Registry) -> Result<App, JsValue>

Mount root into the first element matching selector.

pub fn mount_themed(element: &Element, root: Component, registry: Registry, theme: Theme) -> Result<App, JsValue>

Mount root into element using a custom Tailwind theme.

pub fn mount_to(element: &Element, root: Component, registry: Registry) -> Result<App, JsValue>

Mount root into element with the default theme.

pub fn navigate(path: &str)

Navigate to path (sets location.hash and updates hash_route immediately).

pub fn new_focus_requests(before: &[Vec<usize>], now: &[Vec<usize>]) -> Vec<Vec<usize>>

Focus requests that weren't present after the previous render.

pub fn now_iso() -> String

The current time as an RFC 3339 / ISO 8601 string (UTC).

pub fn orbit_camera(base: &Camera, o: &Orbit) -> Camera

The camera after orbiting base around its target.

pub fn page_data(id: &str) -> Option<Value>

JSON embedded in the page as <script type="application/json" id="…"> (how a host page — Gatsby, a CMS template — hands data to the app).

pub fn path_route() -> Signal<String>

A signal holding location.pathname ("/blog/hello/"), updated by visit and by the browser's back and forward buttons.

pub fn pointer_uv(rect: (f32, f32, f32, f32), x: f32, y: f32) -> (f32, f32)

Pointer position as shader UV (0..1, y up) within rect = (left, top, width, height) in client pixels.

pub fn prefers_reduced_motion() -> bool

Whether the user asked the OS to minimise motion.

pub fn query_value(search: &str, name: &str) -> Option<String>

name's value in a query string (?a=1&b=two+words).

pub fn random() -> f64

A random number in [0, 1).

pub fn recall(key: &str) -> Option<(f64, Value)>

What remember kept under key, and how long ago (milliseconds).

pub fn remember(key: &str, value: &Value)

Keep value in this browser under key (localStorage), with when. Best effort: a full or blocked store keeps nothing.

pub fn spawn(f: impl Future<Output = ()> + 'static)

Run a future on the page's event loop.

pub fn start(selector: &str, root: Component, registry: Registry) -> Result<(), JsValue>

Mount and keep the app alive for the lifetime of the page.

pub fn start_app(selector: &str, routes: Routes, registry: Registry, theme: Theme) -> Result<(), JsValue>

Start an app made from app/ (see weft::app!): render the page at the browser's path in its layouts, keep the document's title in step, and, unless the app's mode is mpa, show its pages without loading them when their links are clicked.

pub fn start_themed(selector: &str, root: Component, registry: Registry, theme: Theme) -> Result<(), JsValue>

start with a custom Tailwind theme.

pub fn stats() -> HostStats

Current debug counters.

pub fn surface_is_animated(el: &VElement) -> bool

Whether a surface needs redrawing every frame.

pub fn surface_resolution(kind: SurfaceKind, css_w: f32, css_h: f32, dpr: f64) -> (u32, u32)

Backing-store size for a surface of css_w × css_h CSS pixels. Shader backgrounds (smooth, full-bleed) render at ≤1× density and a small pixel budget; 3D scenes at ≤2×; 2D canvases at full density. The browser scales the result to the CSS box, so this mostly trades invisible detail for GPU memory and fill rate.

pub fn surface_target(el: &VElement, x: f32, y: f32) -> Option<Vec<usize>>

The child index of the item under (x, y) on a graphics surface.

pub fn sync_attributes(el: &Element, desired: &[(String, String)]) -> Result<(), JsValue>

Make el's attributes equal to desired (host-internal ones are kept).

pub fn tint_svg(svg: &str, color: &str) -> String

An SVG with every hex colour (#rgb, #rrggbb, #rrggbbaa) replaced by color, so an icon can take a particle's colour.

pub fn trap_focus_index(count: usize, current: Option<usize>, backwards: bool) -> usize

Next index when Tab-cycling through count focusable elements inside a modal (current is the focused one, if it is inside).

pub fn visit(url: &str)

Show the page at url (/blog/hello/, /docs/#install) without loading it: push it onto the history and update path_route.

pub const DELEGATED_EVENTS: &[&str] = _;

DOM events listened for (via delegation on the mount root).

pub const INTERNAL_ATTR_PREFIX: &str = "data-weft-";

Prefix attribute names the host owns; attribute syncing never removes them.

pub const MAX_SCENE_PIXELS: u32 = 2_500_000;

Pixel budget for 3D scenes.

pub const MAX_SHADER_PIXELS: u32 = 600_000;

Pixel budget for full-surface shader backgrounds.