private static void CheckAllReferencedProviders(IEnumerable <LoggingProviderBase> referencedProviders,
LoggingProviderChain chain)
{
// Most of the time referenced providers are simply fallback providers.
foreach (var provider in referencedProviders)
{
ValidateProvider(provider, chain);
}
}
private static void ValidateProvider(LoggingProviderBase provider, LoggingProviderChain chain)
{
ThrowWhenProviderIsInChain(provider, chain);
// Note that LoggingProviderChain is immutable. Adding involves creating a new instance.
var chainWithProvider = chain.Add(provider);
CheckAllReferencedProviders(provider.GetReferencedProviders(), chainWithProvider);
}
private static void ThrowWhenProviderIsInChain(LoggingProviderBase providerToValidate,
LoggingProviderChain providersInChain)
{
// Check whether the supplied provider is already directly or indirectly referencing itself.
bool providerIsSelfReferenced = providersInChain.Contains(providerToValidate);
if (providerIsSelfReferenced)
{
throw new ConfigurationErrorsException(
SR.CircularReferenceInLoggingSection(Logger.SectionName, providerToValidate.Name));
}
}
private LoggingProviderChain(LoggingProviderBase provider, LoggingProviderChain list)
{
this.provider = provider;
this.list = list;
}
