001/*
002 * SonarQube
003 * Copyright (C) 2009-2016 SonarSource SA
004 * mailto:contact AT sonarsource DOT com
005 *
006 * This program is free software; you can redistribute it and/or
007 * modify it under the terms of the GNU Lesser General Public
008 * License as published by the Free Software Foundation; either
009 * version 3 of the License, or (at your option) any later version.
010 *
011 * This program is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014 * Lesser General Public License for more details.
015 *
016 * You should have received a copy of the GNU Lesser General Public License
017 * along with this program; if not, write to the Free Software Foundation,
018 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
019 */
020package org.sonar.api;
021
022import java.util.ArrayList;
023import java.util.Collection;
024import java.util.List;
025import org.sonar.api.utils.Version;
026
027import static java.util.Arrays.asList;
028import static java.util.Objects.requireNonNull;
029
030/**
031 * Entry-point for plugins to inject extensions into SonarQube.
032 * <p>The JAR manifest must declare the name of the implementation class in the property <code>Plugin-Class</code>.
033 * This property is automatically set by sonar-packaging-maven-plugin when building plugin.
034 * <p>Example of implementation
035 * <pre>
036 * package com.mycompany.sonarqube;
037 * public class MyPlugin implements Plugin {
038 *  {@literal @}Override
039 *   public void define(Context context) {
040 *     context.addExtensions(MySensor.class, MyRules.class);
041 *     if (context.getSonarQubeVersion().isGreaterThanOrEqual(SonarQubeVersion.V5_6)) {
042 *       // Extension which supports only versions 5.6 and greater
043 *       // See org.sonar.api.SonarQubeVersion for more details.
044 *       context.addExtension(MyNewExtension.class);
045 *     }
046 *   }
047 * }
048 * </pre>
049 *
050 * <p>Example of pom.xml
051 * <pre>
052 * &lt;project&gt;
053 *   ...
054 *   &lt;packaging&gt;sonar-plugin&lt;/packaging&gt;
055 *
056 *   &lt;build&gt;
057 *     &lt;plugins&gt;
058 *       &lt;plugin&gt;
059 *         &lt;groupId&gt;org.sonarsource.sonar-packaging-maven-plugin&lt;/groupId&gt;
060 *         &lt;artifactId&gt;sonar-packaging-maven-plugin&lt;/artifactId&gt;
061 *         &lt;extensions&gt;true&lt;/extensions&gt;
062 *         &lt;configuration&gt;
063 *           &lt;pluginClass&gt;com.mycompany.sonarqube.MyPlugin&lt;/pluginClass&gt;
064 *         &lt;/configuration&gt;
065 *       &lt;/plugin&gt;
066 *     &lt;/plugins&gt;
067 *   &lt;/build&gt;
068 * &lt;/project&gt;
069 * </pre>
070 *
071 * <p>Example of test
072 * <pre>
073 * MyPlugin underTest = new MyPlugin();
074 *
075 *{@literal @}Test
076 * public void test_plugin_extensions_compatible_with_5_5() {
077 *   Plugin.Context context = new Plugin.Context(SonarQubeVersion.V5_5);
078 *   underTest.define(context);
079 *   assertThat(context.getExtensions()).hasSize(4);
080 * }
081 * </pre>
082 *
083 * @since 5.5
084 */
085public interface Plugin {
086
087  class Context {
088    private final Version version;
089    private final List extensions = new ArrayList();
090
091    public Context(Version version) {
092      this.version = version;
093    }
094
095    /**
096     * Runtime version of SonarQube
097     */
098    public Version getSonarQubeVersion() {
099      return version;
100    }
101
102    /**
103     * Add an extension as :
104     * <ul>
105     *   <li>a Class that is annotated with {@link org.sonar.api.batch.BatchSide}, {@link org.sonar.api.server.ServerSide}
106     *   or {@link org.sonar.api.ce.ComputeEngineSide}. The extension will be instantiated once. Its dependencies are
107     *   injected through constructor parameters.</li>
108     *   <li>an instance that is annotated with {@link org.sonar.api.batch.BatchSide}, {@link org.sonar.api.server.ServerSide}
109     *   or {@link org.sonar.api.ce.ComputeEngineSide}.</li>
110     * </ul>
111     * Only a single component can be registered for a class. It's not allowed for example to register:
112     * <ul>
113     *   <li>two MyExtension.class</li>
114     *   <li>MyExtension.class and new MyExtension()</li>
115     * </ul>
116     */
117    public Context addExtension(Object extension) {
118      requireNonNull(extension);
119      this.extensions.add(extension);
120      return this;
121    }
122
123    /**
124     * @see #addExtension(Object)
125     */
126    public Context addExtensions(Collection extensions) {
127      this.extensions.addAll(extensions);
128      return this;
129    }
130
131    /**
132     * @see #addExtension(Object)
133     */
134    public Context addExtensions(Object first, Object second, Object... others) {
135      addExtension(first);
136      addExtension(second);
137      addExtensions(asList(others));
138      return this;
139    }
140
141    public List getExtensions() {
142      return extensions;
143    }
144  }
145
146  /**
147   * This method is executed at runtime when:
148   * <ul>
149   *   <li>Web Server starts</li>
150   *   <li>Compute Engine starts</li>
151   *   <li>Scanner starts</li>
152   * </ul>
153   */
154  void define(Context context);
155}