Class: ElasticGraph::Apollo::GraphQL::EntitiesFieldResolver

Inherits:
Object
  • Object
show all
Defined in:
lib/elastic_graph/apollo/graphql/entities_field_resolver.rb

Overview

GraphQL resolver for the Apollo ‘Query._entities` field. For details on this field, see:

www.apollographql.com/docs/federation/subgraph-spec/#resolve-requests-for-entities

Defined Under Namespace

Classes: RepresentationWithId, RepresentationWithoutId, RepresentationWithoutIndex

Instance Method Summary collapse

Constructor Details

#initialize(datastore_query_builder:, schema_element_names:) ⇒ EntitiesFieldResolver

Returns a new instance of EntitiesFieldResolver.



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# File 'lib/elastic_graph/apollo/graphql/entities_field_resolver.rb', line 22

def initialize(datastore_query_builder:, schema_element_names:)
  @datastore_query_builder = datastore_query_builder
  @schema_element_names = schema_element_names
end

Instance Method Details

#can_resolve?(field:, object:) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/elastic_graph/apollo/graphql/entities_field_resolver.rb', line 27

def can_resolve?(field:, object:)
  field.parent_type.name == :Query && field.name == :_entities
end

#resolve(field:, object:, args:, context:, lookahead:) ⇒ Object 



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# File 'lib/elastic_graph/apollo/graphql/entities_field_resolver.rb', line 31

def resolve(field:, object:, args:, context:, lookahead:)
  schema = context.fetch(:elastic_graph_schema)

  representations = args.fetch("representations").map.with_index do |rep, index|
    try_parse_representation(rep, schema) do |error_description|
      context.add_error(::GraphQL::ExecutionError.new("Representation at index #{index} #{error_description}."))
    end
  end

  representations_by_adapter = representations.group_by { |rep| rep&.adapter }

  # The query attributes that are based on the requested subfields are the same across all representations,
  # so we build the hash of those attributes once here.
  query_attributes = ElasticGraph::GraphQL::QueryAdapter::RequestedFields
    .new(schema)
    .query_attributes_for(field: field, lookahead: lookahead)
    .merge(monotonic_clock_deadline: context[:monotonic_clock_deadline])

  # Build a separate query per adapter instance since each adapter instance is capable of building
  # a single query that handles all representations assigned to it.
  query_by_adapter = representations_by_adapter.to_h do |adapter, reps|
    query = build_query(adapter, reps, query_attributes) if adapter
    [adapter, query]
  end

  responses_by_query = ElasticGraph::GraphQL::Resolvers::QuerySource.execute_many(query_by_adapter.values.compact, for_context: context)
  indexed_search_hits_by_adapter = query_by_adapter.to_h do |adapter, query|
    indexed_search_hits = query ? adapter.index_search_hits(responses_by_query.fetch(query)) : {} # : ::Hash[::String, ElasticGraph::GraphQL::DatastoreResponse::Document]
    [adapter, indexed_search_hits]
  end

  representations.map.with_index do |representation, index|
    next unless (adapter = representation&.adapter)

    indexed_search_hits = indexed_search_hits_by_adapter.fetch(adapter)
    adapter.identify_matching_hit(indexed_search_hits, representation, context: context, index: index)
  end
end