searchFulltextStandard.scala.txt

@*
 * Copyright © 2021 Data and Service Center for the Humanities and/or DaSCH Service Platform contributors.
 * SPDX-License-Identifier: Apache-2.0
 *@

@import org.knora.webapi.IRI
@import org.knora.webapi.exceptions.SparqlGenerationException
@import org.knora.webapi.util.ApacheLuceneSupport.LuceneQueryString


@*
 * Performs a simple full-text search using standard SPARQL (except for the interface to Lucene, which is
 * triplestore-specific), and without inference.
 *
 * The number of rows returned per matching resource is equal to the number of values that matched in the resource,
 * plus one if the resource's label matched.
 *
 * This template is used only by searchFulltext.scala.txt.
 *
 * @param triplestore the name of the triplestore being used.
 * @param searchTerms search terms.
 * @param limitToProject limit search to the given project.
 * @param limitToResourceClass limit search to given resource class.
 * @param limitToStandoffClass limit the search to given standoff class.
 * @param returnFiles if true, return any file value attached to each matching resource.
 * @param separator the separator to be used in aggregation functions.
 * @param limit maximal amount of rows to be returned
 * @param offset offset for paging (starts with 0)
 * @param countQuery indicates whether it is a count query or the actual resources should be returned.
 *@
@(triplestore: String,
  searchTerms: LuceneQueryString,
  limitToProject: Option[IRI],
  limitToResourceClass: Option[IRI],
  limitToStandoffClass: Option[IRI],
  returnFiles: Boolean,
  separator: Option[Char],
  limit: Int,
  offset: Int,
  countQuery: Boolean)

PREFIX knora-base: <http://www.knora.org/ontology/knora-base#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

@if(!countQuery) {
SELECT DISTINCT ?resource
                (GROUP_CONCAT(IF(BOUND(?valueObject), STR(?valueObject), "");
                    separator="@separator.getOrElse(throw SparqlGenerationException("Separator expected for non count query, but none given"))")
                    AS ?valueObjectConcat)
} else {
    SELECT (count(distinct ?resource) as ?count)
}
WHERE {

    {
        SELECT DISTINCT ?matchingSubject WHERE {

            ?matchingSubject <http://jena.apache.org/text#query> '@searchTerms.getQueryString' .

            @* standoff search *@
            @if(limitToStandoffClass.nonEmpty) {

                # ?matchingSubject is expected to be a TextValue
                ?matchingSubject a knora-base:TextValue ;
                    knora-base:valueHasString ?literal ;
                    knora-base:valueHasStandoff ?standoffNode .

                ?standoffNode a <@limitToStandoffClass.get> ;
                    knora-base:standoffTagHasStart ?start ;
                    knora-base:standoffTagHasEnd ?end .

                # https://www.w3.org/TR/xpath-functions/#func-substring
                # The first character of a string is located at position 1, not position 0. -> standoff uses a 0 based index
                BIND(SUBSTR(?literal, ?start+1, ?end - ?start) AS ?markedup)

                @* Loop over search terms and make sure they are all contained in the specified standoff markup *@
                @for(term <- searchTerms.getSingleTerms) {
                    @* TODO: Ignore Lucene operators *@
                    FILTER REGEX(?markedup, '@term', "i")
                }

             }
        }
    }

    OPTIONAL {
        ?matchingSubject a ?valueObjectType .

        ?valueObjectType rdfs:subClassOf *knora-base:Value .

        FILTER(?valueObjectType != knora-base:LinkValue && ?valueObjectType != knora-base:ListValue)

        ?containingResource ?property ?matchingSubject .

        ?property rdfs:subPropertyOf* knora-base:hasValue .

        FILTER NOT EXISTS {
            ?matchingSubject knora-base:isDeleted true
        }

        # this variable will only be bound if the search matched a value object
        BIND(?matchingSubject AS ?valueObject)
    }

    OPTIONAL {
        # get all list nodes that match the search term
        ?matchingSubject a knora-base:ListNode .

        # get sub-node(s) of that node(s) (recursively)
        ?matchingSubject knora-base:hasSubListNode* ?subListNode .

        # get all values that point to the node(s) and sub-node(s)
        ?listValue knora-base:valueHasListNode ?subListNode .

        # get all resources that have that values
        ?subjectWithListValue ?predicate ?listValue .

        FILTER NOT EXISTS {
            ?matchingSubject knora-base:isDeleted true
        }

        # this variable will only be bound if the search matched a list node
        BIND(?listValue AS ?valueObject)
    }

    # If the first OPTIONAL clause was executed, ?matchingSubject is a value object, and ?containingResource will be set as ?valueObject.
    # If the second OPTIONAL clause was executed, ?matchingSubject is a list node, and ?listValue will be set as ?valueObject.
    # Otherwise, ?matchingSubject is a resource (its rdfs:label matched the search pattern).
    BIND(
        COALESCE(
            ?containingResource,
            ?subjectWithListValue,
            ?matchingSubject)
        AS ?resource)

    ?resource a ?resourceClass .

    ?resourceClass rdfs:subClassOf* knora-base:Resource .

    @limitToResourceClass match {
        case Some(definedLimitToResourceClass) => {
            ?resourceClass rdfs:subClassOf* <@definedLimitToResourceClass> .
        }

        case None => {}
    }

    @limitToProject match {
        case Some(definedLimitToProject) => {
            ?resource knora-base:attachedToProject <@definedLimitToProject> .
        }

        case None => {}
    }

    @if(returnFiles) {
        OPTIONAL {
            ?fileValueProp rdfs:subPropertyOf* knora-base:hasFileValue .
            ?resource ?fileValueProp ?valueObject .
        }
    }

    FILTER NOT EXISTS {
        ?resource knora-base:isDeleted true .
    }
}
@if(!countQuery) {
GROUP BY ?resource
ORDER BY ?resource
OFFSET @offset
}
LIMIT @limit