1   /*
2    * Logback: the reliable, generic, fast and flexible logging framework.
3    * Copyright (C) 1999-2026, QOS.ch. All rights reserved.
4    *
5    * This program and the accompanying materials are dual-licensed under
6    * either the terms of the Eclipse Public License v2.0 as published by
7    * the Eclipse Foundation
8    *
9    *   or (per the licensee's choosing)
10   *
11   * under the terms of the GNU Lesser General Public License version 2.1
12   * as published by the Free Software Foundation.
13   */
14  package ch.qos.logback.core.model.processor;
15  
16  import ch.qos.logback.core.Context;
17  import ch.qos.logback.core.model.AppenderRefModel;
18  import ch.qos.logback.core.model.Model;
19  
20  import java.util.List;
21  
22  /**
23   * The AppenderRefDependencyAnalyser class is responsible for analyzing dependencies
24   * related to appender references within a logging model. This class extends
25   * ModelHandlerBase and operates during the dependency analysis phase of processing.
26   *
27   * The primary responsibilities of this class include:
28   * - Identifying instances of {@link AppenderRefModel} within a model hierarchy.
29   * - Substituting references to appender models using the context's interpretation logic.
30   * - Adding dependency definitions for the identified appender references to the interpretation context.
31   */
32  @PhaseIndicator(phase = ProcessingPhase.DEPENDENCY_ANALYSIS)
33  public class AppenderRefDependencyAnalyser extends ModelHandlerBase {
34  
35      public AppenderRefDependencyAnalyser(Context context) {
36          super(context);
37      }
38  
39      @Override
40      protected Class<Model> getSupportedModelClass() {
41          return Model.class;
42      }
43  
44      @Override
45      public void handle(ModelInterpretationContext mic, Model parentModel) throws ModelHandlerException {
46          List<AppenderRefModel> appenderRefModelList = new java.util.ArrayList<>();
47          collectAllAppenderRefModels(appenderRefModelList, parentModel);
48  
49          for (AppenderRefModel appenderRefModel : appenderRefModelList) {
50              // TODO: prevent substitution of references
51              String ref = appenderRefModel.getRef();
52              DependencyDefinition dd = new DependencyDefinition(parentModel, ref);
53              mic.addDependencyDefinition(dd);
54          }
55  
56      }
57  
58      /**
59       * Recursively processes the given Model object and its submodels, extracting instances
60       * of AppenderRefModel and adding them to the provided list.
61       *
62       * @param list the list to which AppenderRefModel instances are added
63       * @param model the root Model object from which to start the extraction
64       */
65      public void collectAllAppenderRefModels(List<AppenderRefModel> list, Model model) {
66          if(model == null)
67              return;
68          if(model instanceof AppenderRefModel) {
69              list.add((AppenderRefModel) model);
70          }
71          model.getSubModels().forEach(subModel -> collectAllAppenderRefModels(list, subModel));
72      }
73  
74  }