Struct HookContext 

pub struct HookContext {
    pub inner: Rc<RefCell<HookContextInner>>,
}

Manages hook state across render cycles for a DynamicNode.

Stores boxed Any values keyed by hook call order, enabling use_signal and similar hooks to persist state between re-renders of the same dynamic node.

Implements Clone for ergonomic use; all clones share the same underlying state.

Fields

inner: Rc<RefCell<HookContextInner>>

Shared reference to the heap-allocated hook context inner state.

Implementations

impl HookContext

Implementation of hook context lifecycle and hook index management.

pub fn reset_index(&mut self)

Resets the hook index for a new render cycle.

Sets the internal hook index back to zero so that subsequent use_signal calls start indexing from the beginning of the hook list.

pub fn switch_arm(&mut self, changed: usize)

Notifies the hook context that a match arm is being entered.

If the arm index has changed, all existing hooks and cleanups are cleared and re-initialized for the new arm. If the arm is unchanged, only the hook index is reset.

Arguments

• usize - The index of the new match arm.

impl HookContext

Associated functions for hook context management.

These are crate-internal static methods for managing the active hook context, creating signals, registering cleanups, and scheduling intervals.

pub fn current() -> HookContext

Returns a shared reference to the current hook context global state.

SAFETY: Must only be called from the main thread (WASM single-threaded context). Returns the currently active HookContext for this thread.

If no hook context has been set, creates and stores a default one in the thread-local CURRENT_HOOK_CONTEXT cell so subsequent calls on this thread return the same instance.

Returns

• HookContext - The currently active hook context.

pub fn with<F, R>(context: HookContext, callback: F) -> R

where F: FnOnce() -> R,

Runs a closure with the given HookContext set as the active context.

Saves the previous context, sets the new one, executes the closure, and restores the previous context afterward. The save/restore pair is scoped to the current thread, so concurrent callers cannot restore each other’s context.

Arguments

• HookContext - The hook context to set as active during closure execution.
• F - The closure to execute with the given context.

Returns

• R - The result of the closure execution.

impl HookContext

Inherent implementation of HookContext.

pub fn use_hook<T, F>(factory: F) -> T

where F: FnOnce() -> T, T: Clone + 'static,

Registers a hook value with the current hook context and returns the existing instance if one was stored at this index from a previous render cycle.

This is the public extension point for custom hook types. ui and downstream crates implement use_form, use_i18n, etc. on top of this primitive instead of poking at the hook array directly. factory runs once per hook slot on the first render; subsequent renders in the same arm return the previously stored instance.

Arguments

• F - Constructor that produces a fresh value of type T when the slot has never been written.

Returns

• T - Either the previously-stored value (cheap clone / copy) or a fresh one from factory.

impl HookContext

pub fn get_inner(&self) -> &Rc<RefCell<HookContextInner>>

pub fn get_mut_inner(&mut self) -> &mut Rc<RefCell<HookContextInner>>

pub fn set_inner(&mut self, val: Rc<RefCell<HookContextInner>>) -> &mut Self

impl HookContext

pub fn new(inner: Rc<RefCell<HookContextInner>>) -> Self

Trait Implementations

impl Clone for HookContext

Clones the hook context, sharing the same inner state.

All clones share the same underlying Rc<RefCell<HookContextInner>>, so modifications through one clone are visible through all others.

Returns

• Self - A new HookContext sharing the same inner state.

fn clone(&self) -> Self

Clones the HookContext by reusing shared, cheap-to-clone state where possible.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for HookContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the struct fields as a debug struct, skipping excluded fields.

Arguments

• &mut std::fmt::Formatter<'_> - The formatter to write the representation into.

Returns

• std::fmt::Result - Success or failure of the formatting operation.

impl Default for HookContext

Provides a default empty hook context.

Creates a fresh Rc<RefCell<HookContextInner>> with default values (empty hook list, zero hook index, empty cleanup list).

Returns

• Self - A new HookContext with default inner state.

fn default() -> Self

Constructs a default HookContext value.