Util/ReflectionFu.cs

   1 //
   2 // ReflectionFu.cs
   3 //
   4 // Copyright (C) 2004-2006 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a
   9 // copy of this software and associated documentation files (the "Software"),
  10 // to deal in the Software without restriction, including without limitation
  11 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12 // and/or sell copies of the Software, and to permit persons to whom the
  13 // Software is furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in
  16 // all copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24 // DEALINGS IN THE SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.Collections;
  29 using System.IO;
  30 using System.Reflection;
  31
  32 namespace Beagle.Util {
  33
  34         public class ReflectionFu {
  35
  36                 public delegate void ForeachDirMethod (Assembly a);
  37
  38                 static public ArrayList ScanEnvironmentForAssemblies (string env_var, string fallback_path)
  39                 {
  40                         return ScanEnvironmentForAssemblies (env_var, fallback_path, null);
  41                 }
  42
  43                 static public ArrayList ScanEnvironmentForAssemblies (string env_var, string fallback_path, ForeachDirMethod method)
  44                 {
  45                         ArrayList assemblies = new ArrayList ();
  46
  47                         string path = Environment.GetEnvironmentVariable (env_var);
  48
  49                         if (path == null || path == "")
  50                                 path = fallback_path;
  51                         else if (path [path.Length-1] == ':')
  52                                 path += fallback_path;
  53
  54                         Hashtable seen = new Hashtable ();
  55
  56                         foreach (string dir in path.Split (':')) {
  57                                 if (! seen.Contains (dir)) {
  58                                         foreach (Assembly a in ScanDirectoryForAssemblies (dir)) {
  59                                                 assemblies.Add (a);
  60
  61                                                 if (method != null)
  62                                                         method (a);
  63                                         }
  64                                 }
  65
  66                                 seen [dir] = true;
  67                         }
  68
  69                         return assemblies;
  70                 }
  71
  72                 static public ArrayList ScanDirectoryForAssemblies (string dir)
  73                 {
  74                         ArrayList assemblies = new ArrayList ();
  75
  76                         if (dir == null || dir == "")
  77                                 return assemblies;
  78
  79                         if (! Directory.Exists (dir)) {
  80                                 Logger.Log.Debug ("'{0}' is not a directory: Nothing loaded from here", dir);
  81                                 return assemblies;
  82                         }
  83
  84                         DirectoryInfo dir_info = new DirectoryInfo (dir);
  85                         foreach (FileInfo file_info in dir_info.GetFiles ()) {
  86                                 if (file_info.Extension == ".dll") {
  87                                         Assembly a = Assembly.LoadFrom (file_info.FullName);
  88                                         assemblies.Add (a);
  89                                 }
  90                         }
  91
  92                         return assemblies;
  93                 }
  94
  95                 static public ArrayList ScanAssemblyForClass (Assembly assembly, Type supertype)
  96                 {
  97                         ArrayList subclasses = new ArrayList ();
  98
  99                         foreach (Type t in assembly.GetTypes ()) {
 100                                 if (t.IsSubclassOf (supertype) && ! t.IsAbstract)
 101                                         subclasses.Add (t);
 102                         }
 103
 104                         return subclasses;
 105                 }
 106
 107                 static public ArrayList ScanAssemblyForInterface (Assembly assembly, Type iface)
 108                 {
 109                         ArrayList implementors = new ArrayList ();
 110
 111                         foreach (Type t in assembly.GetTypes ()) {
 112                                 if (t.GetInterface (iface.ToString ()) != null)
 113                                         implementors.Add (t);
 114                         }
 115
 116                         return implementors;
 117                 }
 118
 119                 static public ArrayList ScanTypeForAttribute (Type type, Type attribute_type)
 120                 {
 121                         ArrayList attrs = new ArrayList ();
 122
 123                         object[] attributes = Attribute.GetCustomAttributes (type);
 124                         foreach (object obj in attributes) {
 125                                 Type obj_type = obj.GetType ();
 126
 127                                 if (obj_type == attribute_type || obj_type.IsSubclassOf (attribute_type))
 128                                         attrs.Add (obj);
 129                         }
 130
 131                         return attrs;
 132                 }
 133         }
 134 }