Package org.hibernate.search.engine.search.projection.dsl

Interface SearchProjectionFactory<R,​E>

  • Type Parameters:
    R - The type of entity references, i.e. the type of objects returned for entity reference projections.
    E - The type of entities, i.e. the type of objects returned for entity projections.
    All Known Subinterfaces:
    ElasticsearchSearchProjectionFactory<R,​E>, ExtendedSearchProjectionFactory<S,​R,​E>, LuceneSearchProjectionFactory<R,​E>
    All Known Implementing Classes:
    AbstractSearchProjectionFactory
    public interface SearchProjectionFactory<R,​E>
    A factory for search projections.

    Field paths

    By default, field paths passed to this DSL are interpreted as absolute, i.e. relative to the index root.

    However, a new, "relative" factory can be created with withRoot(String): the new factory interprets paths as relative to the object field passed as argument to the method.

    This can be useful when calling reusable methods that can apply the same projection on different object fields that have same structure (same sub-fields).

    Such a factory can also transform relative paths into absolute paths using toAbsolutePath(String); this can be useful for native projections in particular.

    • Method Detail

      • entityReference

        EntityReferenceProjectionOptionsStep<?,​R> entityReference()
        Project to a reference to the entity that was originally indexed.

        The actual type of the reference depends on the mapper used to create the query: the ORM mapper will return a class/identifier pair, for example.

        Returns:
        A DSL step where the "entity reference" projection can be defined in more details.

      • id

        default IdProjectionOptionsStep<?,​Object> id()
        Project to the identifier of the referenced entity, i.e. the value of the property marked as @DocumentId.
        Returns:
        A DSL step where the "id" projection can be defined in more details.

      • id

        <I> IdProjectionOptionsStep<?,​I> id​(Class<I> identifierType)
        Project to the identifier of the referenced entity, i.e. the value of the property marked as @DocumentId.
        Type Parameters:
        I - The expected type of the identifier
        Parameters:
        identifierType - The expected type of the identifier
        Returns:
        A DSL step where the "id" projection can be defined in more details.
        Throws:
        SearchException - if the identifier type doesn't match

      • entity

        EntityProjectionOptionsStep<?,​E> entity()
        Project to the entity was originally indexed.

        The actual type of the entity depends on the mapper used to create the query and on the indexes targeted by your query: the ORM mapper will return a managed entity loaded from the database, for example.

        Returns:
        A DSL step where the "entity" projection can be defined in more details.

      • field

        default <T> FieldProjectionValueStep<?,​T> field​(String fieldPath,
                                                      Class<T> type)
        Project to the value of a field in the indexed document.

        This method will apply projection converters on data fetched from the backend. See ValueConvert.YES.

        Type Parameters:
        T - The resulting type of the projection.
        Parameters:
        fieldPath - The path to the index field whose value will be extracted.
        type - The resulting type of the projection.
        Returns:
        A DSL step where the "field" projection can be defined in more details.

      • field

        <T> FieldProjectionValueStep<?,​T> field​(String fieldPath,
                                              Class<T> type,
                                              ValueConvert convert)
        Project to the value of a field in the indexed document.
        Type Parameters:
        T - The resulting type of the projection.
        Parameters:
        fieldPath - The path to the index field whose value will be extracted.
        type - The resulting type of the projection.
        convert - Controls how the data fetched from the backend should be converted. See ValueConvert.
        Returns:
        A DSL step where the "field" projection can be defined in more details.

      • field

        default FieldProjectionValueStep<?,​Object> field​(String fieldPath)
        Project to the value of a field in the indexed document, without specifying a type.

        This method will apply projection converters on data fetched from the backend. See ValueConvert.YES.

        Parameters:
        fieldPath - The path to the index field whose value will be extracted.
        Returns:
        A DSL step where the "field" projection can be defined in more details.

      • field

        FieldProjectionValueStep<?,​Object> field​(String fieldPath,
                                               ValueConvert convert)
        Project to the value of a field in the indexed document, without specifying a type.
        Parameters:
        fieldPath - The path to the index field whose value will be extracted.
        convert - Controls how the data fetched from the backend should be converted. See ValueConvert.
        Returns:
        A DSL step where the "field" projection can be defined in more details.

      • score

        ScoreProjectionOptionsStep<?> score()
        Project on the score of the hit.
        Returns:
        A DSL step where the "score" projection can be defined in more details.

      • distance

        DistanceToFieldProjectionValueStep<?,​Double> distance​(String fieldPath,
                                                            GeoPoint center)
        Project on the distance from the center to a GeoPoint field.
        Parameters:
        fieldPath - The path to the index field containing the location to compute the distance from.
        center - The center to compute the distance from.
        Returns:
        A DSL step where the "distance" projection can be defined in more details.

      • composite

        default CompositeProjectionOptionsStep<?,​List<?>> composite​(SearchProjection<?>... projections)
        Create a projection that will compose a List based on the given projections.
        Parameters:
        projections - The projections used to populate the list, in order.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        default CompositeProjectionOptionsStep<?,​List<?>> composite​(ProjectionFinalStep<?>... dslFinalSteps)
        Create a projection that will compose a List based on the given almost-built projections.
        Parameters:
        dslFinalSteps - The final steps in the projection DSL allowing the retrieval of SearchProjections.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        <T> CompositeProjectionOptionsStep<?,​T> composite​(Function<List<?>,​T> transformer,
                                                        SearchProjection<?>... projections)
        Create a projection that will compose a custom object based on the given projections.
        Type Parameters:
        T - The type of the custom object composing the projected elements.
        Parameters:
        transformer - The function that will transform the list of projected elements into a custom object.
        projections - The projections used to populate the list, in order.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        default <T> CompositeProjectionOptionsStep<?,​T> composite​(Function<List<?>,​T> transformer,
                                                                ProjectionFinalStep<?>... dslFinalSteps)
        Create a projection that will compose a custom object based on the given almost-built projections.
        Type Parameters:
        T - The type of the custom object composing the projected elements.
        Parameters:
        transformer - The function that will transform the projected element into a custom object.
        dslFinalSteps - The final steps in the projection DSL allowing the retrieval of SearchProjections.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        <P,​T> CompositeProjectionOptionsStep<?,​T> composite​(Function<P,​T> transformer,
                                                                SearchProjection<P> projection)
        Create a projection that will compose a custom object based on one given projection.
        Type Parameters:
        P - The type of the element passed to the transformer.
        T - The type of the custom object composing the projected element.
        Parameters:
        transformer - The function that will transform the projected element into a custom object.
        projection - The original projection used to produce the element passed to the transformer.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        default <P,​T> CompositeProjectionOptionsStep<?,​T> composite​(Function<P,​T> transformer,
                                                                        ProjectionFinalStep<P> dslFinalStep)
        Create a projection that will compose a custom object based on one almost-built projection.
        Type Parameters:
        P - The type of the element passed to the transformer.
        T - The type of the custom object composing the projected element.
        Parameters:
        transformer - The function that will transform the projected element into a custom object.
        dslFinalStep - The final step in the projection DSL allowing the retrieval of the SearchProjection that will be used to produce the element passed to the transformer.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        <P1,​P2,​T> CompositeProjectionOptionsStep<?,​T> composite​(BiFunction<P1,​P2,​T> transformer,
                                                                          SearchProjection<P1> projection1,
                                                                          SearchProjection<P2> projection2)
        Create a projection that will compose a custom object based on two given projections.
        Type Parameters:
        P1 - The type of the first element passed to the transformer.
        P2 - The type of the second element passed to the transformer.
        T - The type of the custom object composing the projected elements.
        Parameters:
        transformer - The function that will transform the projected elements into a custom object.
        projection1 - The projection used to produce the first element passed to the transformer.
        projection2 - The projection used to produce the second element passed to the transformer.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        default <P1,​P2,​T> CompositeProjectionOptionsStep<?,​T> composite​(BiFunction<P1,​P2,​T> transformer,
                                                                                  ProjectionFinalStep<P1> dslFinalStep1,
                                                                                  ProjectionFinalStep<P2> dslFinalStep2)
        Create a projection that will compose a custom object based on two almost-built projections.
        Type Parameters:
        P1 - The type of the first element passed to the transformer.
        P2 - The type of the second element passed to the transformer.
        T - The type of the custom object composing the projected elements.
        Parameters:
        transformer - The function that will transform the projected elements into a custom object.
        dslFinalStep1 - The final step in the projection DSL allowing the retrieval of the SearchProjection that will be used to produce the first element passed to the transformer.
        dslFinalStep2 - The final step in the projection DSL allowing the retrieval of the SearchProjection that will be used to produce the second element passed to the transformer.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        <P1,​P2,​P3,​T> CompositeProjectionOptionsStep<?,​T> composite​(TriFunction<P1,​P2,​P3,​T> transformer,
                                                                                   SearchProjection<P1> projection1,
                                                                                   SearchProjection<P2> projection2,
                                                                                   SearchProjection<P3> projection3)
        Create a projection that will compose a custom object based on three given projections.
        Type Parameters:
        P1 - The type of the first element passed to the transformer.
        P2 - The type of the second element passed to the transformer.
        P3 - The type of the third element passed to the transformer.
        T - The type of the custom object composing the projected elements.
        Parameters:
        transformer - The function that will transform the projected elements into a custom object.
        projection1 - The projection used to produce the first element passed to the transformer.
        projection2 - The projection used to produce the second element passed to the transformer.
        projection3 - The projection used to produce the third element passed to the transformer.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • composite

        default <P1,​P2,​P3,​T> CompositeProjectionOptionsStep<?,​T> composite​(TriFunction<P1,​P2,​P3,​T> transformer,
                                                                                           ProjectionFinalStep<P1> dslFinalStep1,
                                                                                           ProjectionFinalStep<P2> dslFinalStep2,
                                                                                           ProjectionFinalStep<P3> dslFinalStep3)
        Create a projection that will compose a custom object based on three almost-built projections.
        Type Parameters:
        P1 - The type of the first element passed to the transformer.
        P2 - The type of the second element passed to the transformer.
        P3 - The type of the third element passed to the transformer.
        T - The type of the custom object composing the projected elements.
        Parameters:
        transformer - The function that will transform the projected elements into a custom object.
        dslFinalStep1 - The final step in the projection DSL allowing the retrieval of the SearchProjection that will be used to produce the first element passed to the transformer.
        dslFinalStep2 - The final step in the projection DSL allowing the retrieval of the SearchProjection that will be used to produce the second element passed to the transformer.
        dslFinalStep3 - The final step in the projection DSL allowing the retrieval of the SearchProjection that will be used to produce the third element passed to the transformer.
        Returns:
        A DSL step where the "composite" projection can be defined in more details.

      • extension

        <T> T extension​(SearchProjectionFactoryExtension<T,​R,​E> extension)
        Extend the current factory with the given extension, resulting in an extended factory offering different types of projections.
        Type Parameters:
        T - The type of factory provided by the extension.
        Parameters:
        extension - The extension to the projection DSL.
        Returns:
        The extended factory.
        Throws:
        SearchException - If the extension cannot be applied (wrong underlying backend, ...).

      • extension

        <T> SearchProjectionFactoryExtensionIfSupportedStep<T,​R,​E> extension()
        Create a DSL step allowing multiple attempts to apply extensions one after the other, failing only if none of the extensions is supported.

        If you only need to apply a single extension and fail if it is not supported, use the simpler extension(SearchProjectionFactoryExtension) method instead.

        This method is generic, and you should set the generic type explicitly to the expected projected type, e.g. .<MyProjectedType>extension().

        Type Parameters:
        T - The expected projected type.
        Returns:
        A DSL step.

      • withRoot

        @Incubating
SearchProjectionFactory<R,​E> withRoot​(String objectFieldPath)
        Create a new projection factory whose root for all paths passed to the DSL will be the given object field.

        This is used to call reusable methods that can apply the same projection on different object fields that have same structure (same sub-fields).

        Parameters:
        objectFieldPath - The path from the current root to an object field that will become the new root.
        Returns:
        A new projection factory using the given object field as root.

      • toAbsolutePath

        @Incubating
String toAbsolutePath​(String relativeFieldPath)
        Parameters:
        relativeFieldPath - The path to a field, relative to the root of this factory.
        Returns:
        The absolute path of the field, for use in native projections for example. Note the path is returned even if the field doesn't exist.