Enum yew::callback::Callback

pub enum Callback<IN> {
    Callback(Rc<dyn Fn(IN)>),
    CallbackOnce(Rc<RefCell<Option<Box<dyn FnOnce(IN)>>>>),
}

Universal callback wrapper.

Use callbacks carefully, because if you call it from `update` loop of `Components` (even from JS) it will delay a message until next. Callbacks should be used from JS callbacks or `setTimeout` calls.

`Rc` wrapper used to make it clonable.

Variants

Callback(Rc<dyn Fn(IN)>)

A callback that can be called multiple times

CallbackOnce(Rc<RefCell<Option<Box<dyn FnOnce(IN)>>>>)

A callback that will only be called once. Panics if it is called again

Methods

impl<IN> Callback<IN>

pub fn emit(&self, value: IN)

This method calls the actual callback.

pub fn once<F>(func: F) -> Self where
    F: FnOnce(IN) + 'static, 

Creates a callback from a FnOnce. You are responsible for ensuring the callback is only called once otherwise it will panic.

pub fn noop() -> Self

Creates a no-op callback which can be used when it is not suitable to use an Option<Callback>.

impl<IN: 'static> Callback<IN>

pub fn reform<F, T>(&self, func: F) -> Callback<T> where
    F: Fn(T) -> IN + 'static, 

Changes input type of the callback to another. Works like common map method but in an opposite direction.

Trait Implementations

impl<IN> Clone for Callback<IN>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<IN> Debug for Callback<IN>

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

Formats the value using the given formatter.

impl<IN> Default for Callback<IN>

fn default() -> Self

Returns the "default value" for a type.

impl<IN, F: Fn(IN) + 'static> From<F> for Callback<IN>

fn from(func: F) -> Self

Performs the conversion.

impl<IN> PartialEq<Callback<IN>> for Callback<IN>

fn eq(&self, other: &Callback<IN>) -> bool

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

#[must_use]fn ne(&self, other: &Rhs) -> bool

This method tests for !=.