Struct MaybeProp

pub struct MaybeProp<T, S = SyncStorage>(/* private fields */)
where
    T: 'static,
    S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>;

A wrapping type for an optional component prop.

This can either be a signal or a non-reactive value, and may or may not have a value. In other words, this is an Option<Signal<Option<T>>>, but automatically flattens its getters.

This creates an extremely flexible type for component libraries, etc.

Examples

let (count, set_count) = signal(Some(2));
let double = |n| n * 2;
let double_count = MaybeProp::derive(move || count.get().map(double));
let memoized_double_count = Memo::new(move |_| count.get().map(double));
let static_value = 5;

// this function takes either a reactive or non-reactive value
fn above_3(arg: &MaybeProp<i32>) -> bool {
    // ✅ calling the signal clones and returns the value
    //    it is a shorthand for arg.get()q
    arg.get().map(|arg| arg > 3).unwrap_or(false)
}

assert_eq!(above_3(&None::<i32>.into()), false);
assert_eq!(above_3(&static_value.into()), true);
assert_eq!(above_3(&count.into()), false);
assert_eq!(above_3(&double_count), true);
assert_eq!(above_3(&memoized_double_count.into()), true);

Implementations

impl<T> MaybeProp<T>

where T: Send + Sync,

pub fn derive( derived_signal: impl Fn() -> Option<T> + Send + Sync + 'static, ) -> MaybeProp<T>

Wraps a derived signal, i.e., any computation that accesses one or more reactive signals.

impl<T> MaybeProp<T, LocalStorage>

pub fn derive_local( derived_signal: impl Fn() -> Option<T> + 'static, ) -> MaybeProp<T, LocalStorage>

Wraps a derived signal, i.e., any computation that accesses one or more reactive signals.

Trait Implementations

impl<T, S> Clone for MaybeProp<T, S>

where S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

fn clone(&self) -> MaybeProp<T, S>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T, S> Debug for MaybeProp<T, S>

where T: Debug + 'static, S: Debug + Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

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

Formats the value using the given formatter.

impl<T, S> Default for MaybeProp<T, S>

where S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

fn default() -> MaybeProp<T, S>

Returns the “default value” for a type.

impl<T, S> DefinedAt for MaybeProp<T, S>

where S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

fn defined_at(&self) -> Option<&'static Location<'static>>

Returns the location at which the signal was defined. This is usually simply None in release mode.

impl From<&str> for MaybeProp<String>

fn from(value: &str) -> MaybeProp<String>

Converts to this type from the input type.

impl From<&str> for MaybeProp<String, LocalStorage>

fn from(value: &str) -> MaybeProp<String, LocalStorage>

Converts to this type from the input type.

impl<T> From<MaybeProp<T>> for Option<Signal<Option<T>>>

where T: Send + Sync + 'static,

fn from(value: MaybeProp<T>) -> Option<Signal<Option<T>>>

Converts to this type from the input type.

impl<T> From<MaybeProp<T, LocalStorage>> for Option<Signal<Option<T>, LocalStorage>>

where T: Send + Sync + 'static,

fn from( value: MaybeProp<T, LocalStorage>, ) -> Option<Signal<Option<T>, LocalStorage>>

Converts to this type from the input type.

impl<T> From<MaybeSignal<Option<T>>> for MaybeProp<T>

where T: Send + Sync, SyncStorage: Storage<Option<T>>,

fn from(value: MaybeSignal<Option<T>>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<MaybeSignal<Option<T>, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync,

fn from( value: MaybeSignal<Option<T>, LocalStorage>, ) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<Memo<Option<T>>> for MaybeProp<T>

where T: Send + Sync,

fn from(value: Memo<Option<T>>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<Memo<Option<T>, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync,

fn from(value: Memo<Option<T>, LocalStorage>) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<Memo<T>> for MaybeProp<T>

where T: Send + Sync + Clone,

fn from(value: Memo<T>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<Memo<T, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync + Clone,

fn from(value: Memo<T, LocalStorage>) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<Option<MaybeSignal<Option<T>>>> for MaybeProp<T>

where T: Send + Sync, SyncStorage: Storage<Option<T>>,

fn from(value: Option<MaybeSignal<Option<T>>>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<Option<MaybeSignal<Option<T>, LocalStorage>>> for MaybeProp<T, LocalStorage>

where T: Send + Sync,

fn from( value: Option<MaybeSignal<Option<T>, LocalStorage>>, ) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<Option<T>> for MaybeProp<T>

where T: Send + Sync, SyncStorage: Storage<Option<T>>,

fn from(value: Option<T>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<ReadSignal<Option<T>>> for MaybeProp<T>

where T: Send + Sync,

fn from(value: ReadSignal<Option<T>>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<ReadSignal<Option<T>, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync,

fn from( value: ReadSignal<Option<T>, LocalStorage>, ) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<ReadSignal<T>> for MaybeProp<T>

where T: Send + Sync + Clone,

fn from(value: ReadSignal<T>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<ReadSignal<T, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync + Clone,

fn from(value: ReadSignal<T, LocalStorage>) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<RwSignal<Option<T>>> for MaybeProp<T>

where T: Send + Sync,

fn from(value: RwSignal<Option<T>>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<RwSignal<Option<T>, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync,

fn from(value: RwSignal<Option<T>, LocalStorage>) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<RwSignal<T>> for MaybeProp<T>

where T: Send + Sync + Clone,

fn from(value: RwSignal<T>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<RwSignal<T, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync + Clone,

fn from(value: RwSignal<T, LocalStorage>) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<Signal<Option<T>>> for MaybeProp<T>

where T: Send + Sync, SyncStorage: Storage<Option<T>>,

fn from(value: Signal<Option<T>>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<Signal<Option<T>, LocalStorage>> for MaybeProp<T, LocalStorage>

fn from(value: Signal<Option<T>, LocalStorage>) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<Signal<T>> for MaybeProp<T>

where T: Send + Sync + Clone,

fn from(value: Signal<T>) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> From<Signal<T, LocalStorage>> for MaybeProp<T, LocalStorage>

where T: Send + Sync + Clone,

fn from(value: Signal<T, LocalStorage>) -> MaybeProp<T, LocalStorage>

Converts to this type from the input type.

impl<T> From<T> for MaybeProp<T>

where T: Send + Sync, SyncStorage: Storage<Option<T>>,

fn from(value: T) -> MaybeProp<T>

Converts to this type from the input type.

impl<T> FromLocal<Option<T>> for MaybeProp<T, LocalStorage>

fn from_local(value: Option<T>) -> MaybeProp<T, LocalStorage>

Converts between the types.

impl<T> FromLocal<T> for MaybeProp<T, LocalStorage>

fn from_local(value: T) -> MaybeProp<T, LocalStorage>

Converts between the types.

impl IntoClass for MaybeProp<String>

fn into_class(self) -> Class

impl<T, S> PartialEq for MaybeProp<T, S>

where T: PartialEq + 'static, S: PartialEq + Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T, S> ReadUntracked for MaybeProp<T, S>

where T: Clone, S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

type Value = ReadGuard<Option<T>, SignalReadGuard<Option<T>, S>>

The guard type that will be returned, which can be dereferenced to the value.

fn try_read_untracked( &self, ) -> Option<<MaybeProp<T, S> as ReadUntracked>::Value>

Returns the guard, or None if the signal has already been disposed.

fn custom_try_read( &self, ) -> Option<Option<<MaybeProp<T, S> as ReadUntracked>::Value>>

This is a backdoor to allow overriding the Read::try_read implementation despite it being auto implemented.

fn read_untracked(&self) -> Self::Value

Returns the guard.

impl<T, St> Serialize for MaybeProp<T, St>

where T: Send + Sync + Serialize, St: Storage<SignalTypes<Option<T>, St>> + Storage<Option<T>>,

fn serialize<S>( &self, serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl<T, S> Track for MaybeProp<T, S>

where S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

fn track(&self)

Subscribes to this signal in the current reactive scope without doing anything with its value.

impl<T, S> Copy for MaybeProp<T, S>

where S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

impl<T, S> Eq for MaybeProp<T, S>

where T: Eq + 'static, S: Eq + Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,

impl<T, S> StructuralPartialEq for MaybeProp<T, S>

where T: 'static, S: Storage<Option<T>> + Storage<SignalTypes<Option<T>, S>>,