/// <summary>
/// Resolves the lookup but may not fail if missing.
/// </summary>
/// <param name="context">Frontend compiler containing all the objects that may satisfy the resolution.</param>
/// <param name="allowUnresolved">Flag specifying whether to allow unresolved items to be returned.</param>
/// <returns>Item resolved.</returns>
public PackageItem Resolve(FrontendCompiler context, bool allowUnresolved)
{
if (this.ResolvedItem == null)
{
string targetPropertyName = this.targetProperty == null ? String.Empty : this.targetProperty.Name;
CompilerMessage message = null;
PackageItem item = null;
if (context.TryGetItemById(this.Lookup, out item))
{
if (this.targetType.IsInstanceOfType(item))
{
if (this.targetProperty != null)
{
this.SetTarget(context, item);
}
}
else if (!allowUnresolved)
{
message = CompilerMessage.InvalidIdResolution(
targetPropertyName,
this.Lookup,
this.targetType.Name,
item.GetType().Name);
}
}
else if (this.targetType.IsSubclassOf(typeof(FileSystemResource)) || this.targetType == typeof(IFileReference))
{
Resource resource;
FileSystemResourceManager manager = (FileSystemResourceManager)context.GetService(typeof(FileSystemResourceManager));
if (manager.TryFindResourceByPath(context, this.Lookup, out resource))
{
if (this.targetType.IsInstanceOfType(resource))
{
if (this.targetProperty != null)
{
item = this.SetTarget(context, resource);
}
else
{
item = resource;
}
}
else
{
message = CompilerMessage.InvalidIdResolution(
targetPropertyName,
this.Lookup,
this.targetType.Name,
resource.GetType().Name);
}
}
else if (!allowUnresolved)
{
message = CompilerMessage.UnknownFileSystemResolution(
targetPropertyName,
this.Lookup,
this.targetType.Name);
}
}
else if (!allowUnresolved)
{
message = CompilerMessage.UnknownIdResolution(
targetPropertyName,
this.Lookup,
this.targetType.Name);
}
if (message != null)
{
context.OnMessage(new CompilerMessageEventArgs(message, this.targetItem));
}
this.ResolvedItem = item;
}
return(this.ResolvedItem);
}