public AttributeCloner(
TAttribute source,
BindingDataContract bindingDataContract,
INameResolver nameResolver = null,
Func <TAttribute, Task <TAttribute> > hook = null)
{
_hook = hook;
nameResolver = nameResolver ?? new EmptyNameResolver();
_source = source;
Type attributeType = typeof(TAttribute);
PropertyInfo[] allProperties = attributeType.GetProperties(Flags);
// Create dictionary of all non-null properties on source attribute.
Dictionary <string, PropertyInfo> nonNullProps = allProperties
.Where(prop => prop.GetValue(source) != null)
.ToDictionary(prop => prop.Name, prop => prop, StringComparer.OrdinalIgnoreCase);
// Pick the ctor with the longest parameter list where all are matched to non-null props.
var ctorAndParams = attributeType.GetConstructors(Flags)
.Select(ctor => new { ctor = ctor, parameters = ctor.GetParameters() })
.OrderByDescending(tuple => tuple.parameters.Length)
.FirstOrDefault(tuple => tuple.parameters.All(param => nonNullProps.ContainsKey(param.Name)));
if (ctorAndParams == null)
{
throw new InvalidOperationException("Can't figure out which ctor to call.");
}
_matchedCtor = ctorAndParams.ctor;
// Get appropriate binding data resolver (appsetting, autoresolve, or originalValue) for each constructor parameter
_ctorParamResolvers = ctorAndParams.parameters
.Select(param => GetResolver(nonNullProps[param.Name], nameResolver, bindingDataContract))
.ToArray();
// Get appropriate binding data resolver (appsetting, autoresolve, or originalValue) for each writeable property
_propertySetters = allProperties
.Where(prop => prop.CanWrite)
.Select(prop =>
{
var resolver = GetResolver(prop, nameResolver, bindingDataContract);
return((Action <TAttribute, BindingData>)((attr, data) => prop.SetValue(attr, resolver(attr, data))));
})
.ToArray();
}
// transforms binding data to appropriate resolver (appsetting, autoresolve, or originalValue)
private BindingDataResolver GetResolver(PropertyInfo propInfo, INameResolver nameResolver, BindingDataContract contract)
{
object originalValue = propInfo.GetValue(_source);
AppSettingAttribute appSettingAttr = propInfo.GetCustomAttribute <AppSettingAttribute>();
AutoResolveAttribute autoResolveAttr = propInfo.GetCustomAttribute <AutoResolveAttribute>();
if (appSettingAttr != null && autoResolveAttr != null)
{
throw new InvalidOperationException($"Property '{propInfo.Name}' cannot be annotated with both AppSetting and AutoResolve.");
}
// first try to resolve with app setting
if (appSettingAttr != null)
{
return(GetAppSettingResolver((string)originalValue, appSettingAttr, nameResolver, propInfo));
}
// try to resolve with auto resolve ({...}, %...%)
if (autoResolveAttr != null && originalValue != null)
{
_autoResolves[propInfo] = autoResolveAttr;
return(GetTemplateResolver((string)originalValue, autoResolveAttr, nameResolver, propInfo, contract));
}
// resolve the original value
return((newAttr, bindingData) => originalValue);
}
// AutoResolve
internal static BindingDataResolver GetTemplateResolver(string originalValue, AutoResolveAttribute attr, INameResolver nameResolver, PropertyInfo propInfo, BindingDataContract contract)
{
string resolvedValue = nameResolver.ResolveWholeString(originalValue);
var template = BindingTemplate.FromString(resolvedValue);
IResolutionPolicy policy = GetPolicy(attr.ResolutionPolicyType, propInfo);
template.ValidateContractCompatibility(contract);
return((newAttr, bindingData) => TemplateBind(policy, propInfo, newAttr, template, bindingData));
}
