pub trait Readable {
type Target: ?Sized;
type Storage: AnyStorage;
// Required methods
fn try_read_unchecked(
&self,
) -> Result<<Self::Storage as AnyStorage>::Ref<'static, Self::Target>, BorrowError>
where Self::Target: 'static;
fn try_peek_unchecked(
&self,
) -> Result<<Self::Storage as AnyStorage>::Ref<'static, Self::Target>, BorrowError>
where Self::Target: 'static;
fn subscribers(&self) -> Subscribers
where Self::Target: 'static;
}Available on crate feature
prelude only.Expand description
A trait for states that can be read from like crate::Signal, crate::GlobalSignal, or crate::ReadSignal. You may choose to accept this trait as a parameter instead of the concrete type to allow for more flexibility in your API. For example, instead of creating two functions, one that accepts a crate::Signal and one that accepts a crate::GlobalSignal, you can create one function that accepts a Readable type.
§Example
fn double(something_readable: &impl Readable<Target = i32>) -> i32 {
something_readable.cloned() * 2
}
static COUNT: GlobalSignal<i32> = Signal::global(|| 0);
fn MyComponent(count: Signal<i32>) -> Element {
// Since we defined the function in terms of the readable trait, we can use it with any readable type (Signal, GlobalSignal, ReadSignal, etc)
let doubled = use_memo(move || double(&count));
let global_count_doubled = use_memo(|| double(&COUNT));
rsx! {
div {
"Count local: {count}"
"Doubled local: {doubled}"
"Count global: {COUNT}"
"Doubled global: {global_count_doubled}"
}
}
}Required Associated Types§
Sourcetype Storage: AnyStorage
type Storage: AnyStorage
The type of the storage this readable uses.
Required Methods§
Sourcefn try_read_unchecked(
&self,
) -> Result<<Self::Storage as AnyStorage>::Ref<'static, Self::Target>, BorrowError>where
Self::Target: 'static,
fn try_read_unchecked(
&self,
) -> Result<<Self::Storage as AnyStorage>::Ref<'static, Self::Target>, BorrowError>where
Self::Target: 'static,
Try to get a reference to the value without checking the lifetime. This will subscribe the current scope to the signal.
NOTE: This method is completely safe because borrow checking is done at runtime.
Sourcefn try_peek_unchecked(
&self,
) -> Result<<Self::Storage as AnyStorage>::Ref<'static, Self::Target>, BorrowError>where
Self::Target: 'static,
fn try_peek_unchecked(
&self,
) -> Result<<Self::Storage as AnyStorage>::Ref<'static, Self::Target>, BorrowError>where
Self::Target: 'static,
Try to peek the current value of the signal without subscribing to updates. If the value has been dropped, this will return an error.
NOTE: This method is completely safe because borrow checking is done at runtime.
Sourcefn subscribers(&self) -> Subscriberswhere
Self::Target: 'static,
fn subscribers(&self) -> Subscriberswhere
Self::Target: 'static,
Get the underlying subscriber list for this readable. This is used to track when the value changes and notify subscribers.
Dyn Compatibility§
This trait is dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety".