Servant.Util.Combinators.Filtering.Backend

Provides base for filtering backend implementations.

Filtering backend

class FilterBackend backend

Implementation of filtering backend.

Associated Types

type AutoFilteredValue backend a

The part of object which we are filtering on, provided by server backend implementor.

type MatchPredicate backend

A resulting predicate.

type AutoFilterImpl backend a = AutoFilteredValue backend a -> MatchPredicate backend

Implementation of auto filter we provide.

data FilteringApp backend param where

How to apply a filter - what server backend implementor provides.

Constructors

AutoFilteringApp :: Typeable a => AutoFilteredValue backend a -> FilteringApp backend ('TyNamedParam name ('AutoFilter a))

ManualFilteringApp :: Typeable a => (a -> MatchPredicate backend) -> FilteringApp backend ('TyNamedParam name ('ManualFilter a))

class (Typeable filter, FilterBackend backend) => AutoFilterSupport backend filter a where

Implementation of given auto filter type for Beam Postgres backend.

Methods

autoFilterSupport :: filter a -> AutoFilterImpl backend a

Apply given filter to a value.

type FilteringSpecApp backend params = HList (FilteringApp backend) params

Enlists a way to apply each of supported filters at target application backend.

class FilterBackend backend => BackendApplySomeFilter backend (params :: [TyNamedFilter])

Lookups for an appropriate filter application in a given FilteringSpecApp and applies it to a given filter.

Minimal complete definition

backendApplySomeFilter'

Instances

FilterBackend backend => BackendApplySomeFilter (backend :: k) ('[] :: [TyNamedFilter])

Defined in Servant.Util.Combinators.Filtering.Backend

Methods

backendApplySomeFilter' :: FilteringSpecApp backend '[] -> SomeFilter '[] -> Maybe (MatchPredicate backend)

(Typeable fk, Typeable a, FilterBackend backend, KnownSymbol name, BackendApplyTypeFilter backend fk a, BackendApplySomeFilter backend params) => BackendApplySomeFilter (backend :: k) ('TyNamedParam name (fk a) ': params)

Defined in Servant.Util.Combinators.Filtering.Backend

Methods

backendApplySomeFilter' :: FilteringSpecApp backend ('TyNamedParam name (fk a) ': params) -> SomeFilter ('TyNamedParam name (fk a) ': params) -> Maybe (MatchPredicate backend)

typeAutoFiltersSupport :: forall backend a. TypeAutoFiltersSupport backend a => SomeTypeAutoFilter a -> AutoFilterImpl backend a

Safely choose an appropriate filter from supported ones and prepare it for application.

backendApplyFilters :: forall backend params. BackendApplySomeFilter backend params => FilteringSpec params -> FilteringSpecApp backend params -> [MatchPredicate backend]

Applies multiple filters to a set of response fields which matter for filtering.

Server backend implementor API

filterOn :: forall name backend a. Typeable a => AutoFilteredValue backend a -> FilteringApp backend ('TyNamedParam name ('AutoFilter a))

Implement an automatic filter. User-provided filtering operation will do filter on this value.

manualFilter :: forall name backend a. Typeable a => (a -> MatchPredicate backend) -> FilteringApp backend ('TyNamedParam name ('ManualFilter a))

Implement a manual filter. You are provided with a value which user supplied and so you have to construct a Beam predicate involving that value and relevant response fields.