source: trunk/sources/HeuristicLab.PluginInfrastructure/3.3/LightweightApplicationManager.cs @ 5903

Last change on this file since 5903 was 5903, checked in by gkronber, 11 years ago

#1454: renamed parameter and minor changes.

File size: 8.7 KB
Line 
1#region License Information
2/* HeuristicLab
3 * Copyright (C) 2002-2011 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
4 *
5 * This file is part of HeuristicLab.
6 *
7 * HeuristicLab is free software: you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * HeuristicLab is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
19 */
20#endregion
21
22using System;
23using System.Collections.Generic;
24using System.Linq;
25using System.Reflection;
26
27namespace HeuristicLab.PluginInfrastructure {
28
29  /// <summary>
30  /// Lightweight application manager is set as the application manager as long as the plugin infrastructure is uninitialized.
31  /// The list of plugins and applications is empty. The default application manager is necessary to provide the type discovery
32  /// functionality in unit tests.
33  /// </summary>
34  internal sealed class LightweightApplicationManager : IApplicationManager {
35    internal LightweightApplicationManager() {
36      AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);
37    }
38
39    Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args) {
40      return null;
41    }
42
43
44    #region IApplicationManager Members
45    /// <summary>
46    /// Gets an empty list of plugins. (LightweightApplicationManager doesn't support plugin discovery)
47    /// </summary>
48    public IEnumerable<IPluginDescription> Plugins {
49      get { return new IPluginDescription[0]; }
50    }
51
52    /// <summary>
53    /// Gets an empty list of applications. (LightweightApplicationManager doesn't support application discovery)
54    /// </summary>
55    public IEnumerable<IApplicationDescription> Applications {
56      get { return new IApplicationDescription[0]; }
57    }
58
59    /// <summary>
60    /// Creates an instance of all types that are subtypes or the same type of the specified type
61    /// </summary>
62    /// <typeparam name="T">Most general type.</typeparam>
63    /// <returns>Enumerable of the created instances.</returns>
64    public IEnumerable<T> GetInstances<T>() where T : class {
65      return GetInstances(typeof(T)).Cast<T>();
66    }
67
68    /// <summary>
69    /// Creates an instance of all types that are subtypes or the same type of the specified type
70    /// </summary>
71    /// <param name="type">Most general type.</param>
72    /// <returns>Enumerable of the created instances.</returns>
73    public IEnumerable<object> GetInstances(Type type) {
74      List<object> instances = new List<object>();
75      foreach (Type t in GetTypes(type, true)) {
76        object instance = null;
77        try { instance = Activator.CreateInstance(t); }
78        catch { }
79        if (instance != null) instances.Add(instance);
80      }
81      return instances;
82    }
83
84    /// <summary>
85    /// Finds all instantiable types that are subtypes or equal to the specified types.
86    /// </summary>
87    /// <param name="types">Most general types for which to find matching types.</param>
88    /// <remarks>Return only types that are instantiable
89    /// (interfaces, abstract classes... are not returned)</remarks>
90    /// <returns>Enumerable of the discovered types.</returns>
91    public IEnumerable<Type> GetTypes(IEnumerable<Type> types, bool onlyInstantiable = true, bool assignableToAllTypes = true) {
92      IEnumerable<Type> result = GetTypes(types.First(), onlyInstantiable);
93      foreach (Type type in types.Skip(1)) {
94        IEnumerable<Type> discoveredTypes = GetTypes(type, onlyInstantiable);
95        if (assignableToAllTypes) result = result.Intersect(discoveredTypes);
96        else result = result.Union(discoveredTypes);
97      }
98      return result;
99    }
100
101    /// <summary>
102    /// Finds all types that are subtypes or equal to the specified type.
103    /// </summary>
104    /// <param name="type">Most general type for which to find matching types.</param>
105    /// <param name="onlyInstantiable">Return only types that are instantiable
106    /// (interfaces, abstract classes... are not returned)</param>
107    /// <returns>Enumerable of the discovered types.</returns>
108    public IEnumerable<Type> GetTypes(Type type, bool onlyInstantiable = true) {
109      return from asm in AppDomain.CurrentDomain.GetAssemblies()
110             from t in GetTypes(type, asm, onlyInstantiable)
111             select t;
112    }
113
114    /// <summary>
115    /// Gets types that are assignable (same of subtype) to the specified type only from the given assembly.
116    /// </summary>
117    /// <param name="type">Most general type we want to find.</param>
118    /// <param name="assembly">Assembly that should be searched for types.</param>
119    /// <param name="onlyInstantiable">Return only types that are instantiable
120    /// (interfaces, abstract classes...  are not returned)</param>
121    /// <returns>Enumerable of the discovered types.</returns>
122    private static IEnumerable<Type> GetTypes(Type type, Assembly assembly, bool onlyInstantiable = true) {
123      try {
124        var assemblyTypes = assembly.GetTypes();
125
126        return from t in assemblyTypes
127               where CheckTypeCompatibility(type, t)
128               where onlyInstantiable == false || (!t.IsAbstract && !t.IsInterface && !t.HasElementType)
129               where !IsNonDiscoverableType(t)
130               select BuildType(t, type);
131      }
132      catch (TypeLoadException) {
133        return Enumerable.Empty<Type>();
134      }
135      catch (ReflectionTypeLoadException) {
136        return Enumerable.Empty<Type>();
137      }
138    }
139
140    private static bool IsNonDiscoverableType(Type t) {
141      return t.GetCustomAttributes(typeof(NonDiscoverableTypeAttribute), false).Any();
142    }
143
144    private static bool CheckTypeCompatibility(Type type, Type other) {
145      if (type.IsAssignableFrom(other))
146        return true;
147      if (type.IsGenericType && other.IsGenericType) {
148        try {
149          if (type.IsAssignableFrom(other.GetGenericTypeDefinition().MakeGenericType(type.GetGenericArguments())))
150            return true;
151        }
152        catch (Exception) { }
153      }
154      return false;
155    }
156    private static Type BuildType(Type type, Type protoType) {
157      if (type.IsGenericType && protoType.IsGenericType)
158        return type.GetGenericTypeDefinition().MakeGenericType(protoType.GetGenericArguments());
159      else
160        return type;
161    }
162
163    /// <summary>
164    /// Not supported by the LightweightApplicationManager
165    /// </summary>
166    /// <param name="type"></param>
167    /// <param name="plugin"></param>
168    /// <returns></returns>
169    /// <throws>NotSupportedException</throws>
170    public IEnumerable<Type> GetTypes(Type type, IPluginDescription plugin) {
171      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
172    }
173
174    /// <summary>
175    /// Not supported by the LightweightApplicationManager
176    /// </summary>
177    /// <param name="type"></param>
178    /// <param name="plugin"></param>
179    /// <param name="onlyInstantiable"></param>
180    /// <returns></returns>
181    /// <throws>NotSupportedException</throws>
182    public IEnumerable<Type> GetTypes(Type type, IPluginDescription plugin, bool onlyInstantiable = true) {
183      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
184    }
185
186    /// <summary>
187    /// Not supported by the LightweightApplicationManager
188    /// </summary>
189    /// <param name="type"></param>
190    /// <param name="plugin"></param>
191    /// <param name="onlyInstantiable"></param>
192    /// <returns></returns>
193    /// <throws>NotSupportedException</throws>
194    public IEnumerable<Type> GetTypes(IEnumerable<Type> types, IPluginDescription plugin, bool onlyInstantiable = true, bool assignableToAllTypes = true) {
195      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
196    }
197
198    /// <summary>
199    /// Not supported by the LightweightApplicationManager
200    /// </summary>
201    /// <param name="type"></param>
202    /// <returns></returns>
203    /// <throws>NotSupportedException</throws>
204    public IPluginDescription GetDeclaringPlugin(Type type) {
205      throw new NotSupportedException("LightweightApplicationManager doesn't support type discovery for plugins.");
206    }
207
208    #endregion
209  }
210}
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