public static ICollection <ProviderHandler> LoadProvider(params DirectoryInfo[] probingDirectories)
{
if (s_providers == null || s_providers.Count == 0)
{
// Initialize a list that will contain all plugin types discovered
s_providers = new List <ProviderHandler>();
if (probingDirectories != null)
{
// Iterate over the probing directories and look for plugins
foreach (DirectoryInfo directory in probingDirectories)
{
Debug.Assert(directory.Exists, string.Format("Plugins directory does not exist: {0}", directory.FullName));
if (directory.Exists)
{
// Try to load plugins from each dll
foreach (FileInfo file in directory.GetFiles("*.dll"))
{
try
{
// Load the dll into an assembly
Assembly assembly = Assembly.LoadFrom(file.FullName);
// Iterate over all types contained in the assembly
foreach (Type type in assembly.GetTypes())
{
// Only consider public, concrete types that implement IProvider
if (type.IsPublic && !type.IsAbstract && (type.GetInterface(typeof(IProvider).Name) != null))
{
ProviderHandler handler = ProviderHandler.FromType(type);
if (null == handler ||
handler.ProviderId == null ||
handler.ProviderId == Guid.Empty)
{
continue;
}
s_providers.Add(handler);
TraceManager.TraceInformation("Provider {0} {1} is available", handler.ProviderName, handler.ProviderId.ToString());
}
}
}
catch (ReflectionTypeLoadException)
{
TraceManager.TraceInformation("Provider {0} is unavailable. One or more of the requested types cannot be loaded.", file.FullName);
}
catch (Exception)
{
// We try to load all .dll files and some of them just are not providers.
// Just log a warning and move along
TraceManager.TraceWarning("Failed to load the possible provider file: {0}", file.FullName);
}
}
}
}
}
}
return(s_providers);
}
internal ProviderHandler(ProviderHandler fromCopy)
{
m_type = fromCopy.m_type;
m_descriptionAttribute = fromCopy.m_descriptionAttribute;
m_capabilityAttribute = fromCopy.m_capabilityAttribute;
m_provider = (IProvider)Activator.CreateInstance(m_type);
m_internalId = fromCopy.InternalId;
VersionChanged = fromCopy.VersionChanged;
}
/// <summary>
/// Discovers providers under the specified directories and loads them if used in MigrationSources
/// defined in the configuration. It instantiates a unique provider instance for each MigrationSource.
/// </summary>
public Dictionary <Guid, ProviderHandler> LoadProvider(params DirectoryInfo[] probingDirectories)
{
IEnumerable <ProviderHandler> providers = Utility.LoadProvider(probingDirectories);
// Initialize a list that will contain all plugin types discovered
Dictionary <Guid, ProviderHandler> providerHandlers = new Dictionary <Guid, ProviderHandler>();
foreach (ProviderHandler handler in providers)
{
try
{
#region Register Add-Ins
IProvider provider = handler.Provider;
IAddin addIn = provider.GetService(typeof(IAddin)) as IAddin;
if (null != addIn)
{
m_AddinManagementService.RegisterAddin(addIn);
}
#endregion
Guid[] sourceIds = GetMigrationSourceId(handler.ProviderId);
if (sourceIds == null || sourceIds.Length == 0)
{
continue;
}
// try persist provider information to db
handler.FindSaveProvider();
// create a unique provider instance for each migration source
foreach (Guid migrationSource in sourceIds)
{
ProviderHandler providerHandler = new ProviderHandler(handler);
if (!providerHandlers.ContainsKey(migrationSource))
{
providerHandlers.Add(migrationSource, providerHandler);
TraceManager.TraceInformation("Provider {0} {1} is loaded", providerHandler.ProviderName, handler.ProviderId.ToString());
}
}
}
catch (Exception ex)
{
TraceManager.TraceError("A failure occurred while trying to load the {0} Provider: {1}{2}",
handler.ProviderName, Environment.NewLine, ex.ToString());
}
}
return(providerHandlers);
}
