euv_core/vdom/node/
struct.rs

1use super::*;
2
3/// Inner storage for a dynamic node render closure.
4///
5/// Boxes a `dyn FnMut(&mut HookContext) -> VirtualNode` so it can be stored behind `Rc<UnsafeCell<>>`.
6#[derive(CustomDebug, Data, New)]
7pub(crate) struct RenderFnInner {
8    /// The boxed render closure.
9    #[debug(skip)]
10    #[get(pub(crate))]
11    #[get_mut(pub(crate))]
12    #[set(pub(crate))]
13    pub(crate) render_fn: Box<dyn FnMut(&mut HookContext) -> VirtualNode>,
14}
15
16/// Represents a text node in the virtual DOM.
17///
18/// Text nodes may optionally be bound to a reactive signal for automatic updates.
19///
20/// OPT 29: `content` is `Cow<'static, str>` instead of `String` so the
21/// `html!` macro can emit `Cow::Borrowed("...")` for literal text
22/// without allocating a `String` per text node per render. Runtime
23/// text (signals, `format!`, `to_string()`) still falls through to
24/// `Cow::Owned`. The renderer's `set_text_content` and
25/// `create_text_node` calls take `&str`, which is what `Cow<'static, str>`
26/// derefs to, so call sites use `.as_ref()` (yields `&str`).
27#[derive(Clone, CustomDebug, Data, New)]
28pub struct TextNode {
29    /// The text content.
30    #[get(pub(crate))]
31    #[get_mut(pub(crate))]
32    #[set(pub(crate))]
33    pub(crate) content: Cow<'static, str>,
34    /// An optional binder that wires a freshly created DOM `Text` node to
35    /// its backing signal. The binder is invoked once per DOM text node at
36    /// materialization time (`create_dom_with_doc`); it subscribes the
37    /// source signal directly to that node, so no intermediate bridge
38    /// signal is allocated per binding. Kept text nodes are patched in
39    /// place without re-invoking the binder, so re-renders of a bound
40    /// position never accumulate subscriptions.
41    #[debug(skip)]
42    #[get(pub(crate))]
43    #[get_mut(pub(crate))]
44    #[set(pub(crate))]
45    pub(crate) binder: Option<Rc<dyn Fn(&Text)>>,
46}
47
48/// A closure-based dynamic node that re-renders when its dependency signals change.
49///
50/// Holds a shared reference to a heap-allocated render closure that produces a fresh
51/// `VirtualNode` on each evaluation. The renderer subscribes to the closure's
52/// signals and patches the DOM automatically.
53/// Contains a `HookContext` that persists hook state (like `use_signal`) across
54/// re-renders, ensuring that signal values are not reset when the render function
55/// is called again.
56///
57/// Uses `Rc<UnsafeCell<>>` instead of `Rc<RefCell<>>` to avoid runtime borrow
58/// checking overhead. Safety is guaranteed by the single-threaded WASM context.
59/// The `Rc` provides automatic memory management — the render closure is freed
60/// when the last reference (either in the VirtualNode tree or the signal update
61/// callback) is dropped.
62#[derive(Clone, CustomDebug, Data, New)]
63pub struct DynamicNode {
64    /// Shared reference to the heap-allocated render closure inner state.
65    /// `Rc` ensures automatic deallocation; `UnsafeCell` allows mutable access
66    /// without RefCell overhead.
67    #[debug(skip)]
68    #[get(pub(crate))]
69    #[get_mut(pub(crate))]
70    #[set(pub(crate))]
71    pub(crate) render_fn: Rc<UnsafeCell<RenderFnInner>>,
72    /// Persistent hook context for this dynamic node, storing signal
73    /// state and other hook values across render cycles.
74    #[get(pub(crate))]
75    #[get_mut(pub(crate))]
76    #[set(pub(crate))]
77    pub(crate) hook_context: HookContext,
78}
euv_core/vdom/node/struct.rs

euv_core/vdom/node/
struct.rs
