aria::async::AsyncResource< T, Key > Class Template Reference

#include <async_resource.hpp>

Public Types
using	Fetcher = std::function<Task<T>(Key)>

Public Member Functions
	AsyncResource (IExecutor &ui, IExecutor &worker, Fetcher fetcher)
	~AsyncResource ()
	AsyncResource (const AsyncResource &)=delete
AsyncResource &	operator= (const AsyncResource &)=delete
void	fetch (Key key)
	Fetch for key.
void	refresh ()
void	invalidate () noexcept
void	clear ()
void	cancel ()
	Cancel any in-flight fetch and drop its pending write-back, WITHOUT destroying the resource.
bool	has_data () const

Public Attributes
Property< bool > &	is_loading
Property< std::optional<::aria::Error > > &	error
Property< std::string > &	error_message
Property< std::optional< T > > &	data
Property<::aria::Loadable< T > > &	loadable
	Five-state loadable view-model – Idle / Loading / Refreshing / Success / Error.

Member Typedef Documentation

Fetcher

template<typename T, typename Key = int>

using aria::async::AsyncResource< T, Key >::Fetcher = std::function<Task<T>(Key)>

Constructor & Destructor Documentation

AsyncResource() [1/2]

template<typename T, typename Key = int>

aria::async::AsyncResource< T, Key >::AsyncResource ( IExecutor & ui, IExecutor & worker, Fetcher fetcher )

inline

~AsyncResource()

template<typename T, typename Key = int>

aria::async::AsyncResource< T, Key >::~AsyncResource ( )

inline

AsyncResource() [2/2]

template<typename T, typename Key = int>

aria::async::AsyncResource< T, Key >::AsyncResource ( const AsyncResource< T, Key > & )

delete

Member Function Documentation

operator=()

template<typename T, typename Key = int>

AsyncResource & aria::async::AsyncResource< T, Key >::operator= ( const AsyncResource< T, Key > & )

delete

fetch()

template<typename T, typename Key = int>

void aria::async::AsyncResource< T, Key >::fetch ( Key key )

inline

Fetch for key.

If the same key already has fresh data and no invalidate() has been called since, this is a no-op. If a fetch for the same key is already in-flight, it's deduped.

refresh()

template<typename T, typename Key = int>

void aria::async::AsyncResource< T, Key >::refresh ( )

inline

invalidate()

template<typename T, typename Key = int>

void aria::async::AsyncResource< T, Key >::invalidate ( )

inlinenoexcept

clear()

template<typename T, typename Key = int>

void aria::async::AsyncResource< T, Key >::clear ( )

inline

cancel()

template<typename T, typename Key = int>

void aria::async::AsyncResource< T, Key >::cancel ( )

inline

Cancel any in-flight fetch and drop its pending write-back, WITHOUT destroying the resource.

This is the third lifetime axis from the cancellation model (see docs/reference/lifecycle.md L-38 and ROADMAP P1-H): wire it to a view-destroy hook so navigating away mid-request stops the coroutine from resuming against a dead view.

AsyncResource<UserProfile> profile{ui, net, fetch};
engine.bind_view_lifetime(view, [&profile]{ profile.cancel(); });

Stale-while-revalidate is preserved: the last successful data is kept (only the loading flag is cleared), so a re-mounted view still renders the previous value while a fresh fetch()/refresh() runs. The resource remains fully usable afterwards — a cancelled CancellationSource stays cancelled forever, so we re-arm a fresh one here.

Thread: must be called on the graph thread (it writes the observable Properties), exactly like clear() / fetch().

has_data()

template<typename T, typename Key = int>

bool aria::async::AsyncResource< T, Key >::has_data ( ) const

inlinenodiscard

Member Data Documentation

is_loading

template<typename T, typename Key = int>

Property<bool>& aria::async::AsyncResource< T, Key >::is_loading

error

template<typename T, typename Key = int>

Property<std::optional<::aria::Error> >& aria::async::AsyncResource< T, Key >::error

error_message

template<typename T, typename Key = int>

Property<std::string>& aria::async::AsyncResource< T, Key >::error_message

data

template<typename T, typename Key = int>

Property<std::optional<T> >& aria::async::AsyncResource< T, Key >::data

loadable

template<typename T, typename Key = int>

Property<::aria::Loadable<T> >& aria::async::AsyncResource< T, Key >::loadable

Five-state loadable view-model – Idle / Loading / Refreshing / Success / Error.

Always consistent with the four primitive Properties above. UI code typically prefers this surface (one bind, one switch) over the four-handle surface.

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The documentation for this class was generated from the following file:

• modules/async/include/aria/async/async_resource.hpp