// Public methods
public void FindPlugin(string path)
{
Platform.CheckForNullReference(path, "path");
Platform.CheckForEmptyString(path, "path");
try
{
Assembly asm = LoadAssembly(path);
Attribute[] attrs = Attribute.GetCustomAttributes(asm);
foreach (Attribute attr in attrs)
{
if (attr is PluginAttribute)
{
_pluginFiles.Add(path);
break;
}
}
}
catch (BadImageFormatException e)
{
// Encountered an unmanaged DLL in the plugin directory; this is okay
// but we'll log it anyway
Platform.Log(LogLevel.Debug, SR.LogFoundUnmanagedDLL, e.FileName);
}
catch (FileNotFoundException e)
{
Platform.Log(LogLevel.Error, e, "File not found while loading plugin: {0}", path);
throw;
}
catch (Exception e)
{
Platform.Log(LogLevel.Error, e, "Error loading plugin: {0}", path);
throw;
}
}
private string[] FindPlugins(string path)
{
Platform.CheckForNullReference(path, "path");
Platform.CheckForEmptyString(path, "path");
AppDomain domain = null;
string[] pluginFiles = null;
try
{
EventsHelper.Fire(_pluginProgressEvent, this, new PluginLoadedEventArgs(SR.MessageFindingPlugins, null));
// Create a secondary AppDomain where we can load all the DLLs in the plugin directory
#if MONO
domain = AppDomain.CreateDomain("Secondary");
#else
Evidence evidence = new Evidence(
new object[] { new Zone(SecurityZone.MyComputer) },
new object[] { });
PermissionSet permissions =
SecurityManager.ResolvePolicy(evidence);
AppDomainSetup setup = new AppDomainSetup();
setup.ApplicationBase = AppDomain.CurrentDomain.SetupInformation.ApplicationBase;
#region fix plugin loading problem in ASP.NET
// Apparently we need to use the same lookup paths from the original app domain
// if the application is launched by ASP.NET. The original app domain
// has reference to the "bin" folder where all reference dll's in the webpage are kept (auto copied by
// VS.NET when you add references). If this is not set, calling
//
// domain.CreateInstanceAndUnwrap(asm.FullName, "ClearCanvas.Common.PluginFinder")
//
// will cause file-not-found exception
//
// To be safe, it's best to copy the original PrivateBinPath instead of hardcoding "Bin"
//
setup.PrivateBinPath = AppDomain.CurrentDomain.SetupInformation.PrivateBinPath;
setup.ConfigurationFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile;
#endregion
domain = AppDomain.CreateDomain(
"Secondary", evidence, setup,
permissions, new StrongName[] { });
#endif
Assembly asm = Assembly.GetExecutingAssembly();
// Instantiate the finder in the secondary domain
PluginFinder finder = domain.CreateInstanceAndUnwrap(asm.FullName, "ClearCanvas.Common.PluginFinder") as PluginFinder;
// Assign the FileProcessor's delegate to the finder
FileProcessor.ProcessFile del = new FileProcessor.ProcessFile(finder.FindPlugin);
// Process the plugin directory
FileProcessor.Process(path, "*.dll", del, true);
// Get the list of legitimate plugin DLLs
pluginFiles = finder.PluginFiles;
}
catch (Exception e)
{
Platform.Log(LogLevel.Error, e);
throw; // TH (Oct 5, 2007) replaced "throw e" with "throw". "throw e" produces a new exception stack. We want to know where the original exception occurs instead
}
finally
{
// Unload the domain so that we free up memory used on loading non-plugin DLLs
if (domain != null)
{
AppDomain.Unload(domain);
}
if (pluginFiles == null)
{
throw new PluginException(SR.ExceptionNoPluginsFound);
}
}
return(pluginFiles);
}