/// <summary>
/// Refreshes the <see cref="ComposablePartDefinition"/>s with the latest files in the directory that match
/// the searchPattern. If any files have been added they will be added to the catalog and if any files were
/// removed they will be removed from the catalog. For files that have been removed keep in mind that the
/// assembly cannot be unloaded from the process so <see cref="ComposablePartDefinition"/>s for those files
/// will simply be removed from the catalog.
///
/// Possible exceptions that can be thrown are any that <see cref="Directory.GetFiles(string, string)"/>.
/// </summary>
/// <exception cref="DirectoryNotFoundException">
/// The specified path has been removed since object construction.
/// </exception>
public void Refresh()
{
ThrowIfDisposed();
ComposablePartDefinition[] addedDefinitions;
ComposablePartDefinition[] removedDefinitions;
object changeReferenceObject;
string[] afterFiles;
string[] beforeFiles;
while (true)
{
afterFiles = GetFiles();
lock (_thisLock)
{
changeReferenceObject = _loadedFiles;
beforeFiles = _loadedFiles.ToArray();
}
var newCatalog = ExecuteScripts(afterFiles);
// Notify listeners to give them a preview before completing the changes
addedDefinitions = newCatalog.ToArray();
removedDefinitions = _catalog.ToArray();
using (var atomicComposition = new AtomicComposition())
{
var changingArgs = new ComposablePartCatalogChangeEventArgs(addedDefinitions, removedDefinitions, atomicComposition);
OnChanging(changingArgs);
// if the change went through then write the catalog changes
lock (_thisLock)
{
if (changeReferenceObject != _loadedFiles)
{
// Someone updated the list while we were diffing so we need to try the diff again
continue;
}
_catalog = newCatalog;
_loadedFiles = afterFiles.ToReadOnlyCollection();
// Lastly complete any changes added to the atomicComposition during the change event
atomicComposition.Complete();
// Break out of the while(true)
break;
} // WriteLock
} // AtomicComposition
} // while (true)
var changedArgs = new ComposablePartCatalogChangeEventArgs(addedDefinitions, removedDefinitions, null);
OnChanged(changedArgs);
}
