content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you under the Apache License, Version 2.0 (the
   *  "License"); you may not use this file except in compliance
   *  with the License.  You may obtain a copy of the License at
   *
   *        http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing,
   *  software distributed under the License is distributed on an
   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   *  KIND, either express or implied.  See the License for the
   *  specific language governing permissions and limitations
   *  under the License.
   */
  package org.apache.causeway.viewer.graphql.model.domain;
  
  import graphql.schema.DataFetchingEnvironment;
  import graphql.schema.GraphQLFieldDefinition;
  
  import org.apache.causeway.core.config.CausewayConfiguration;
  import org.apache.causeway.viewer.graphql.model.context.Context;
  import org.apache.causeway.viewer.graphql.model.domain.rich.scenario.ScenarioStep;
  
  import lombok.Getter;
  
  public abstract class Element {
  
      protected final Context context;
      protected final CausewayConfiguration.Viewer.Graphql graphqlConfiguration;
  
      /**
       * Usually populated, being the field that will be added to the parent's type
       *
       * <p>
       *     However, {@link ScenarioStep} is an exception; it doesn't populate this field - instead
       *     {@link ElementCustom#newField(String, String)} is used to create multiple fields for the type.
       * </p>
       */
      @Getter
      private GraphQLFieldDefinition field;
  
      protected Element(final Context context) {
          this.context = context;
          this.graphqlConfiguration = this.context.causewayConfiguration.getViewer().getGraphql();
      }
  
      protected final GraphQLFieldDefinition setField(final GraphQLFieldDefinition field) {
          this.field = field;
          return field;
      }
  
      public final void addDataFetcher(Parent parent) {
          if (getField() != null) {
              // in some cases there might not be a field, eg RichCollectionGet for DomainObjectList#objects
              context.codeRegistryBuilder.dataFetcher(
                      parent.coordinatesFor(getField()),
                      this::fetchData);
          }
  
          addDataFetchersForChildren();
      }
  
      /**
       * Use the provided fieldName rather than that of {@link #getField()}.
       *
       * <p>
       *     Used to allow multiple fields of the same type, eg {@link ScenarioStep}.
       * </p>
       */
      public final void addDataFetcher(Parent parent, String fieldName) {
          context.codeRegistryBuilder.dataFetcher(
                  parent.coordinatesFor(fieldName),
                  this::fetchData);
  
          addDataFetchersForChildren();
      }
  
      protected void addDataFetchersForChildren() {
      }
  
      protected abstract Object fetchData(DataFetchingEnvironment environment);
  }
  