Struct leptos::Trigger

pub struct Trigger { /* private fields */ }

Reactive Trigger, notifies reactive code to rerun.

See create_trigger for more.

Implementations

impl Trigger

pub fn new() -> Trigger

Creates a Trigger, a kind of reactive primitive.

A trigger is a data-less signal with the sole purpose of notifying other reactive code of a change. This can be useful for when using external data not stored in signals, for example.

This is identical to create_trigger.

use std::{cell::RefCell, fmt::Write, rc::Rc};

let external_data = Rc::new(RefCell::new(1));
let output = Rc::new(RefCell::new(String::new()));

let rerun_on_data = Trigger::new();

let o = output.clone();
let e = external_data.clone();
create_effect(move |_| {
    // can be `rerun_on_data()` on nightly
    rerun_on_data.track();
    write!(o.borrow_mut(), "{}", *e.borrow());
    *e.borrow_mut() += 1;
});
assert_eq!(*output.borrow(), "1");

rerun_on_data.notify(); // reruns the above effect

assert_eq!(*output.borrow(), "12");

pub fn notify(&self)

Notifies any reactive code where this trigger is tracked to rerun.

Panics

Panics if there is no current reactive runtime, or if the trigger has been disposed.

pub fn try_notify(&self) -> bool

Attempts to notify any reactive code where this trigger is tracked to rerun.

Returns false if there is no current reactive runtime.

pub fn track(&self)

Subscribes the running effect to this trigger.

Panics

Panics if there is no current reactive runtime, or if the trigger has been disposed.

pub fn try_track(&self) -> bool

Attempts to subscribe the running effect to this trigger, returning false if there is no current reactive runtime.

Trait Implementations

impl Clone for Trigger

fn clone(&self) -> Trigger

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Trigger

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

Formats the value using the given formatter.

impl Default for Trigger

fn default() -> Trigger

Returns the “default value” for a type.

impl PartialEq for Trigger

fn eq(&self, other: &Trigger) -> 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 !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl SignalGet for Trigger

type Value = ()

The value held by the signal.

fn get(&self)

Clones and returns the current value of the signal, and subscribes the running effect to this signal.

fn try_get(&self) -> Option<()>

Clones and returns the signal value, returning Some if the signal is still alive, and None otherwise.

impl SignalSet for Trigger

type Value = ()

The value held by the signal.

fn set(&self, _: ())

Sets the signal’s value and notifies subscribers.

fn try_set(&self, _: ()) -> Option<()>

Sets the signal’s value and notifies subscribers. Returns None if the signal is still valid, [Some(T)] otherwise.

impl SignalUpdate for Trigger

type Value = ()

The value held by the signal.

fn update(&self, f: impl FnOnce(&mut ()))

Applies a function to the current value to mutate it in place and notifies subscribers that the signal has changed.

fn try_update<O>(&self, f: impl FnOnce(&mut ()) -> O) -> Option<O>

Applies a function to the current value to mutate it in place and notifies subscribers that the signal has changed. Returns [Some(O)] if the signal is still valid, None otherwise.

impl Copy for Trigger

impl Eq for Trigger

impl StructuralPartialEq for Trigger