Struct sycamore_reactive::Signal

pub struct Signal<T: 'static> { /* fields omitted */ }

State that can be set.

Example

use sycamore_reactive::*;

let state = Signal::new(0);
assert_eq!(*state.get(), 0);

state.set(1);
assert_eq!(*state.get(), 1);

Implementations

impl<T: 'static> Signal<T>

pub fn new(initial: T) -> Self

Creates a new signal with the given value.

Example

let state = Signal::new(0);

pub fn set(&self, new_value: T)

Set the current value of the state.

This will notify and update any effects and memos that depend on this value.

Example

let state = Signal::new(0);
assert_eq!(*state.get(), 0);

state.set(1);
assert_eq!(*state.get(), 1);

pub fn handle(&self) -> StateHandle<T>

Get the StateHandle associated with this signal.

This is a shortcut for (*signal).clone().

pub fn into_handle(self) -> StateHandle<T>

Consumes this signal and returns its underlying StateHandle.

pub fn trigger_subscribers(&self)

Calls all the subscribers without modifying the state. This can be useful when using patterns such as inner mutability where the state updated will not be automatically triggered. In the general case, however, it is preferable to use Signal::set instead.

Methods from Deref<Target = StateHandle<T>>

pub fn get(&self) -> Rc<T>

Get the current value of the state. When called inside a reactive scope, calling this will add itself to the scope’s dependencies.

Example

use sycamore_reactive::*;

let state = Signal::new(0);
assert_eq!(*state.get(), 0);

state.set(1);
assert_eq!(*state.get(), 1);

pub fn get_untracked(&self) -> Rc<T>

Get the current value of the state, without tracking this as a dependency if inside a reactive context.

Example

use sycamore_reactive::*;

let state = Signal::new(1);

let double = create_memo({
    let state = state.clone();
    move || *state.get_untracked() * 2
});

assert_eq!(*double.get(), 2);

state.set(2);
// double value should still be old value because state was untracked
assert_eq!(*double.get(), 2);

Trait Implementations

impl<T: 'static> Clone for Signal<T>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Signal<T>

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

Formats the value using the given formatter.

impl<T: Default> Default for Signal<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: 'static> Deref for Signal<T>

type Target = StateHandle<T>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T: Hash> Hash for Signal<T>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T: PartialEq> PartialEq<Signal<T>> for Signal<T>

fn eq(&self, other: &Signal<T>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<T: Eq> Eq for Signal<T>