Enum QueryState 

pub enum QueryState<T: Clone> {
    Idle,
    Loading,
    Refetching(T),
    Success(T),
    Stale(T),
    Error {
        error: QueryError,
        stale_data: Option<T>,
    },
}

Represents the state of a query.

This enum carries data in its variants for ergonomic pattern matching:

match state {
    QueryState::Success(data) => { /* use data directly */ }
    QueryState::Error { error, stale_data } => { /* handle error */ }
    QueryState::Loading => { /* show spinner */ }
    _ => {}
}

Variants

Idle

Initial state, no data yet

Loading

Currently fetching (first time)

Refetching(T)

Data available, refetching in background

Success(T)

Fresh data available

Stale(T)

Data is stale but still usable

Error

Error occurred (with optional stale data)

Fields

error: QueryError

stale_data: Option<T>

Implementations

impl<T: Clone> QueryState<T>

pub fn is_idle(&self) -> bool

pub fn is_loading(&self) -> bool

pub fn is_fetching(&self) -> bool

pub fn is_success(&self) -> bool

pub fn is_stale(&self) -> bool

pub fn is_error(&self) -> bool

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

Get data if available (success, stale, refetching, or error with stale)

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

Get error if in error state

pub fn unwrap_or_default(&self) -> T

where T: Default,

Unwrap data or return default

Trait Implementations

impl<T: Clone + Clone> Clone for QueryState<T>

fn clone(&self) -> QueryState<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug + Clone> Debug for QueryState<T>

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

Formats the value using the given formatter.

impl<T: Clone> Default for QueryState<T>

fn default() -> QueryState<T>

Returns the “default value” for a type.