An ES Mapping Modifier to add related descriptor names to a resources indexed document

search_mapping_modifier.py

"""
Assuming this file is saved to a directory called 'utils' in a project called 'someproject', 
add the following to project's setting.py: 

ES_MAPPING_MODIFIER_CLASSES = ["someproject.utils.search_mapping_modifier.RelatedResourceEsMappingModifier"]
"""

from arches.app.search.es_mapping_modifier import EsMappingModifier
from arches.app.search.elasticsearch_dsl_builder import Bool, Match, Nested
from arches.app.models import models

class RelatedResourceEsMappingModifier(EsMappingModifier):

    counter = 1

    def __init__(self):
        pass

    @staticmethod
    def add_search_terms(resourceinstance, document, terms):
        if EsMappingModifier.get_mapping_property() not in document:
            document[EsMappingModifier.get_mapping_property()] = []
        first_hop = models.ResourceXResource.objects.filter(resourceinstanceidfrom=resourceinstance).values_list('resourceinstanceidto', flat=True)
        second_hop = models.ResourceXResource.objects.filter(resourceinstanceidfrom__in=first_hop)
        names = " ".join([str(relationship.resourceinstanceidto.name) for relationship in second_hop])
        document[EsMappingModifier.get_mapping_property()].append(
            {
                "custom_value": names
            }
        )
        RelatedResourceEsMappingModifier.counter = RelatedResourceEsMappingModifier.counter + 1

    @staticmethod
    def create_nested_custom_filter(term, original_element):
        if "nested" not in original_element:
            return original_element
        document_key = EsMappingModifier.get_mapping_property()
        custom_filter = Bool()
        custom_filter.should(
            Match(
                field="%s.custom_value" % document_key,
                query=term["value"],
                type="phrase_prefix",
            )
        )
        custom_filter.should(
            Match(
                field="%s.custom_value.folded" % document_key,
                query=term["value"],
                type="phrase_prefix",
            )
        )
        nested_custom_filter = Nested(path=document_key, query=custom_filter)
        new_must_element = Bool()
        new_must_element.should(original_element)
        new_must_element.should(nested_custom_filter)
        new_must_element.dsl["bool"]["minimum_should_match"] = 1
        return new_must_element

    @staticmethod
    def add_search_filter(search_query, term):
        original_must_filter = search_query.dsl["bool"]["must"]
        search_query.dsl["bool"]["must"] = []
        for must_element in original_must_filter:
            search_query.must(
                RelatedResourceEsMappingModifier.create_nested_custom_filter(term, must_element)
            )

        original_must_filter = search_query.dsl["bool"]["must_not"]
        search_query.dsl["bool"]["must_not"] = []
        for must_element in original_must_filter:
            search_query.must_not(
                RelatedResourceEsMappingModifier.create_nested_custom_filter(term, must_element)
            )