// TODO: Use real log here - and throw a fatal exception instead of swallowing the missing assembly/type
private void LogConfigError(
CacheConfigLoadErrorsException loadErrors, string error, Exception ex = null)
{
System.Diagnostics.Debug.WriteLine(
ex != null
? $"{typeof(CacheConfigurationHandler).FullName}: {error}, Exception: {ex}"
: $"{typeof(CacheConfigurationHandler).FullName}: {error}");
loadErrors.Add(
new CacheConfigLoadErrorsException.CacheConfigLoadError
{
Error = error, Exception = ex
});
}
public object Create(object parent, object configContext, System.Xml.XmlNode section)
{
var loadErrors = new CacheConfigLoadErrorsException();
var assemblies = new Dictionary <string, Assembly>();
var configuration = new List <ConfigNode>();
foreach (XmlNode child in section.ChildNodes)
{
if (child.NodeType != XmlNodeType.Element)
{
continue;
}
var actionName = child.Name;
if (!Enum.TryParse(actionName, true, out ConfigAction action))
{
LogConfigError(loadErrors, $"Unrecognized {typeof(ConfigAction).FullName}: {child.Name}");
continue;
}
var nameNode = child.Attributes?["name"];
if (string.IsNullOrWhiteSpace(nameNode?.Value))
{
LogConfigError(loadErrors, "Attribute 'name' is missing for one or more config nodes");
continue;
}
if (action == ConfigAction.Remove)
{
configuration.Add(new RemoveConfig {
Action = ConfigAction.Remove, Name = nameNode.Value
});
continue;
}
var assemblyNode = child.Attributes["assembly"];
if (string.IsNullOrWhiteSpace(assemblyNode?.Value))
{
LogConfigError(loadErrors, $"Attribute 'assembly' is missing for {child.Name}");
continue;
}
var typeNode = child.Attributes["type"];
if (string.IsNullOrWhiteSpace(typeNode?.Value))
{
LogConfigError(loadErrors, $"Attribute 'type' is missing for {child.Name}");
continue;
}
var typeName = typeNode.Value + "Config";
if (!assemblies.TryGetValue(assemblyNode.Value, out var assembly))
{
try
{
assembly = Assembly.Load(assemblyNode.Value);
}
catch (Exception ex) when(ex is FileLoadException ||
ex is FileNotFoundException ||
ex is BadImageFormatException)
{
LogConfigError(loadErrors, $"Could not load assembly {assemblyNode.Value}", ex);
continue;
}
assemblies.Add(assemblyNode.Value, assembly);
}
var configType = assembly.GetType(typeName, false, false);
if (configType == null)
{
configType = assembly.GetType(assemblyNode.Value + '.' + typeName, false, false);
}
if (configType == null)
{
LogConfigError(loadErrors, $"Could not load type {typeName} from assembly {assemblyNode.Value}");
continue;
}
if (configType.IsSubclassOf(typeof(ConfigNode)) == false)
{
LogConfigError(loadErrors, $"{configType.FullName} is not a sub class of {typeof(ConfigNode).FullName}");
continue;
}
var node = configType.GetConstructor(new Type[0])?.Invoke(new object[0]);
if (node == null)
{
LogConfigError(loadErrors, $"Failed to create an instance of type {configType.FullName} using default constructor");
continue;
}
if (!(node is ConfigNode configNode))
{
LogConfigError(loadErrors, $"{node.GetType().FullName} is not a sub class of {typeof(ConfigNode).FullName}");
continue;
}
ApplyConfig(configuration, child.Attributes, configType, action, configNode, loadErrors);
}
if (!loadErrors.IsEmpty())
{
throw loadErrors;
}
return(configuration);
}
private void ApplyConfig(
List <ConfigNode> configuration, XmlAttributeCollection attributes,
Type configType, ConfigAction action, ConfigNode cacheConfig,
CacheConfigLoadErrorsException loadErrors)
{
cacheConfig.Action = action;
// ReSharper disable once PossibleNullReferenceException
foreach (XmlAttribute childAttrib in attributes)
{
if (childAttrib.NodeType != XmlNodeType.Attribute)
{
continue;
}
if (string.Compare(childAttrib.Name, "name", StringComparison.InvariantCultureIgnoreCase) == 0)
{
cacheConfig.Name = childAttrib.Value;
continue;
}
if (string.Compare(childAttrib.Name, "type", StringComparison.InvariantCultureIgnoreCase) == 0 ||
string.Compare(childAttrib.Name, "assembly", StringComparison.InvariantCultureIgnoreCase) == 0)
{
continue;
}
var configProperty = configType.GetProperties()
.FirstOrDefault(p =>
string.Compare(childAttrib.Name, p.Name, StringComparison.InvariantCultureIgnoreCase) == 0);
if (configProperty == null || !configProperty.CanWrite)
{
LogConfigError(loadErrors, $"No writable property named {childAttrib.Name} found on type {configType.FullName}");
continue;
}
object value;
try
{
if (configProperty.PropertyType == typeof(string))
{
value = childAttrib.Value;
}
else
{
value = Newtonsoft.Json.JsonConvert.DeserializeObject(
childAttrib.Value, configProperty.PropertyType);
}
}
catch (Newtonsoft.Json.JsonSerializationException ex)
{
LogConfigError(loadErrors, $"Could not deserialize {childAttrib.Value} to {configProperty.PropertyType.FullName}", ex);
continue;
}
configProperty.SetValue(cacheConfig, value);
}
configuration.Add(cacheConfig);
}
