Enum RemoteData 

pub enum RemoteData<T, E = String> {
    NotAsked,
    Loading,
    Success(T),
    Failure(E),
}

The four states of an asynchronously loaded value.

E, the error type, defaults to String — the common case after FetchError::to_string().

Variants

NotAsked

Nothing has been asked for yet; the initial state.

Loading

A request is in flight.

Success(T)

The value has arrived.

Failure(E)

The request failed.

Implementations

impl<T, E> RemoteData<T, E>

pub fn from_result(res: Result<T, E>) -> Self

Builds from an effect’s Result: Ok → Success, Err → Failure. The natural bridge inside update.

pub fn is_loading(&self) -> bool

Is a request in flight?

pub fn is_success(&self) -> bool

Has the value arrived?

pub fn is_failure(&self) -> bool

Did the request fail?

pub fn value(&self) -> Option<&T>

The value if it has arrived, None otherwise.

pub fn error(&self) -> Option<&E>

The error if the request failed, None otherwise.

pub fn as_ref(&self) -> RemoteData<&T, &E>

Borrows the inside: RemoteData<T, E> → RemoteData<&T, &E>, so a view can fold over it without consuming the state.

pub fn map<U>(self, f: impl FnOnce(T) -> U) -> RemoteData<U, E>

Transforms the value on success, leaving the other states untouched — decoding a JSON body into a domain type, say.

pub fn map_err<F>(self, f: impl FnOnce(E) -> F) -> RemoteData<T, F>

Transforms the error on failure, leaving the other states untouched.

Trait Implementations

impl<T: Clone, E: Clone> Clone for RemoteData<T, E>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug, E: Debug> Debug for RemoteData<T, E>

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

Formats the value using the given formatter.

impl<T, E> Default for RemoteData<T, E>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Eq, E: Eq> Eq for RemoteData<T, E>

impl<T: PartialEq, E: PartialEq> PartialEq for RemoteData<T, E>

fn eq(&self, other: &Self) -> bool

Equality operator ==.

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

Inequality operator !=.

impl<T: PartialEq, E: PartialEq> StructuralPartialEq for RemoteData<T, E>