/// <summary>
/// Creates the type of the configuration object.
/// </summary>
/// <param name="settings">
/// The settings used to control how configuration objects are created and the features they support.
/// </param>
/// <typeparam name="TConfigurationObject">
/// The type of the interface to be implemented by the configuration object to create.
/// </typeparam>
/// <returns>
/// An implementation of the interface specified that can be used to interact with the configuration.
/// </returns>
/// <exception cref="InvalidOperationException">
/// Type specifies more than one 'Path' attribute and so cannot be processed. - or - Property specifies more
/// than one 'Path' attribute and so cannot be processed.
/// </exception>
internal static Type GenerateConfigurationObjectType<TConfigurationObject>(ConfigurationObjectSettings settings)
where TConfigurationObject : IConfigurationObject
{
var type = typeof(TConfigurationObject);
return GenerateConfigurationObjectType(type, settings);
}
/// <summary>
/// Initializes a new instance of the <see cref="ConfigurationObjectTypeBuilder" /> class.
/// </summary>
/// <param name="interfaceType">
/// The type of the interface.
/// </param>
/// <param name="propertyDefs">
/// The definitions of the interface's properties.
/// </param>
/// <param name="settings">
/// Optional settings used to control how configuration objects are created and the features they support.
/// </param>
public ConfigurationObjectTypeBuilder(Type interfaceType, IEnumerable <PropertyDef> propertyDefs, ConfigurationObjectSettings settings)
{
// TODO: Make type builders cacheable.
_interfaceType = interfaceType;
_propertyDefs = propertyDefs.ToArray();
_baseClassType = typeof(ConfigurationObjectBase <>).MakeGenericType(_interfaceType);
_settings = settings;
settings.ConfigureEnvironment();
}
/// <summary>
/// Creates the type of the configuration object.
/// </summary>
/// <param name="type">
/// The type of the interface to be implemented by the configuration object to create.
/// </param>
/// <param name="settings">
/// The settings used to control how configuration objects are created and the features they support.
/// </param>
/// <returns>
/// An implementation of the interface specified that can be used to interact with the configuration.
/// </returns>
/// <exception cref="InvalidOperationException">
/// Type specifies more than one 'Path' attribute and so cannot be processed. - or - Property specifies more
/// than one 'Path' attribute and so cannot be processed.
/// </exception>
internal static Type GenerateConfigurationObjectType(Type type, ConfigurationObjectSettings settings)
{
var propertyDefs = GetConfigurationObjectDefinition(type, settings);
var builder = new ConfigurationObjectTypeBuilder(type, propertyDefs, settings);
var generatedType = builder.Generate();
return generatedType;
}
/// <summary>
/// Add a new kind of configuration reader that represents values taken directly from the
/// <see cref="IConfigurationRoot" /> object in the service collection.
/// </summary>
/// <typeparam name="TConfigurationObject">
/// The interface through which consumers will access the configuration. This must be derived from the
/// <see cref="IConfigurationObject" /> interface.
/// </typeparam>
/// <param name="serviceCollection">
/// The service collection to which to add the configuration reader. This must not be <see langword="null" />.
/// </param>
/// <param name="configureOptions">
/// A method or lambda that will configure the settings used to control how configuration objects are
/// created and the features they support.
/// </param>
/// <exception cref="ArgumentNullException">
/// <paramref name="configureOptions" /> is <see langword="null" />.
/// </exception>
public static IServiceCollection AddConfigurationReader<TConfigurationObject>(this IServiceCollection serviceCollection, Action<ConfigurationObjectSettings> configureOptions)
where TConfigurationObject : IConfigurationObject
{
configureOptions.Validate(nameof(configureOptions), ObjectIs.NotNull);
var settings = new ConfigurationObjectSettings();
configureOptions(settings);
return AddConfigurationReader<TConfigurationObject>(serviceCollection, settings);
}
/// <summary>
/// Add a new kind of configuration reader that represents values taken directly from the
/// <see cref="IConfigurationRoot" /> object in the service collection.
/// </summary>
/// <typeparam name="TConfigurationObject">
/// The interface through which consumers will access the configuration. This must be derived from the
/// <see cref="IConfigurationObject" /> interface.
/// </typeparam>
/// <param name="serviceCollection">
/// The service collection to which to add the configuration reader. This must not be <see langword="null" />.
/// </param>
/// <param name="settings">
/// Optional settings used to control how configuration objects are created and the features they support.
/// </param>
public static IServiceCollection AddConfigurationReader<TConfigurationObject>(this IServiceCollection serviceCollection, ConfigurationObjectSettings? settings)
where TConfigurationObject : IConfigurationObject
{
serviceCollection.Validate(nameof(serviceCollection), ObjectIs.NotNull);
// Check to see if the collection has the relevant configuration reader registered, and if not, create and
// add a new instance.
if(ReferenceEquals(settings, null))
{
// Use default values.
settings = new ConfigurationObjectSettings();
}
var serviceType = typeof(TConfigurationObject);
if(serviceCollection.Any(d => d.ServiceType == serviceType))
{
return serviceCollection;
}
var implementationType = GenerateConfigurationObjectType<TConfigurationObject>(settings);
var descriptor = new ServiceDescriptor(serviceType, (provider) =>
{
var configurationRoot = provider.GetService<IConfigurationRoot>();
if(_validators.Count <= 0)
{
foreach(var validator in provider.GetServices<IConfigurationObjectValidator>())
{
_validators.Add(validator);
}
}
var validators = GetValidatorsEx<TConfigurationObject>();
var configurationObject = (TConfigurationObject)Activator.CreateInstance(implementationType, null, configurationRoot, null, settings, validators);
configurationObject.Load();
return configurationObject;
}, ServiceLifetime.Singleton);
serviceCollection.TryAdd(descriptor);
return serviceCollection;
}
/// <summary>
/// Initializes a new instance of the <see cref="Implementation" /> class.
/// </summary>
/// <param name="underlyingType">
/// The underlying type of the property or collection represented.
/// </param>
/// <param name="settings">
/// The settings used to control how configuration objects are created and the features they support.
/// </param>
internal Implementation(Type underlyingType, ConfigurationObjectSettings settings)
{
ImplementationKind = GetImplementationKind(underlyingType, out var isReadOnlyColectionType);
_settings = settings;
Type elementType;
switch (ImplementationKind)
{
case ImplementationKind.ConfigurationObject:
ImplementationType = ServiceCollectionExtensions.GenerateConfigurationObjectType(underlyingType, settings);
Type = underlyingType;
break;
case ImplementationKind.ConfigurationCollection:
elementType = underlyingType.GenericTypeArguments.First();
if (isReadOnlyColectionType)
{
ImplementationType = typeof(ReadOnlyConfigurationCollection <>).MakeGenericType(elementType);
}
else
{
ImplementationType = typeof(ConfigurationCollection <>).MakeGenericType(elementType);
}
Type = elementType;
break;
case ImplementationKind.ConfigurationDictionary:
elementType = underlyingType.GenericTypeArguments.First();
if (isReadOnlyColectionType)
{
ImplementationType = typeof(ReadOnlyConfigurationDictionary <>).MakeGenericType(elementType);
}
else
{
ImplementationType = typeof(ConfigurationDictionary <>).MakeGenericType(elementType);
}
Type = elementType;
break;
default:
ImplementationType = null;
Type = underlyingType;
break;
}
}
/// <summary>
/// Gets the configuration object definition.
/// </summary>
/// <param name="type">
/// The type of the object to define.
/// </param>
/// <param name="settings">
/// The settings used to control how configuration objects are created and the features they support.
/// </param>
/// <returns>
/// A list of the property definitions for the type specified.
/// </returns>
/// <exception cref="InvalidOperationException">
/// Type '{type.Namespace}.{type.Name}' specifies more than one 'Path' attribute and so cannot be processed.
/// </exception>
internal static List<PropertyDef> GetConfigurationObjectDefinition(Type type, ConfigurationObjectSettings settings)
{
// TODO: Circular reference detection - for this version.
var propertyDefs = new List<PropertyDef>();
foreach(var property in type.GetProperties(BindingFlags.Instance | BindingFlags.Public))
{
if(!property.CanRead)
{
continue;
}
var propertyDef = new PropertyDef(property, settings);
propertyDefs.Add(propertyDef);
}
return propertyDefs;
}
/// <summary>
/// Initializes a new instance of the <see cref="PropertyDef" /> class.
/// </summary>
/// <param name="propertyInfo">
/// The definition of the property.
/// </param>
/// <param name="settings">
/// The settings used to control how configuration objects are created and the features they support.
/// </param>
/// <exception cref="InvalidPropertyException">
/// 'ConfigurationValue' attribute on property specifies that persistence should only save values (not
/// load), but no default value is provided.
/// </exception>
internal PropertyDef(PropertyInfo propertyInfo, ConfigurationObjectSettings settings)
{
PropertyInfo = propertyInfo;
PropertyName = propertyInfo.Name;
Type = propertyInfo.PropertyType;
Settings = settings;
if (Type.IsArray)
{
throw new InvalidPropertyException(PropertyName, $@"Property '{PropertyName}' is an array which is not supported. Use 'IConfigurationCollection' or 'IReadOnlyConfigurationCollection' instead.");
}
UnderlyingType = GetUnderlyingType(propertyInfo.PropertyType);
IsReadOnly = !propertyInfo.CanWrite;
var pathAttributes = propertyInfo.GetCustomAttributes(typeof(PathAttribute), true);
if (pathAttributes.Length > 0)
{
var pathAttribute = ((PathAttribute)pathAttributes[0]);
PathSection = pathAttribute.Path;
PathModifier = pathAttribute.Usage;
}
else
{
PathModifier = PathIs.Relative;
PathSection = PropertyName;
}
Implementation = new Implementation(UnderlyingType, Settings);
switch (Implementation.ImplementationKind)
{
case ImplementationKind.ConfigurationCollection:
case ImplementationKind.ConfigurationDictionary:
case ImplementationKind.ConfigurationObject:
ElementImplementation = new Implementation(Implementation.Type, Settings);
break;
}
var configurationAttributes = propertyInfo.GetCustomAttributes <ConfigurationAttribute>(true).ToList();
if (configurationAttributes.Count > 0)
{
var attribute = configurationAttributes[0];
DefaultValue = attribute.DefaultValue;
HasDefaultValue = attribute.IsDefaultValueSet;
Persistence = attribute.Persistence;
if (HasDefaultValue)
{
if (ReferenceEquals(DefaultValue, null))
{
if (Type.IsValueType)
{
throw new ConfigurationException(null, PropertyName, string.Format(CultureInfo.InvariantCulture, "Property '{0}' has a default value of a type of 'null', which is incompatible with the type of the property.", PropertyName));
}
}
else
{
if (!Type.IsAssignableFrom(DefaultValue.GetType()))
{
throw new ConfigurationException(null, PropertyName, string.Format(CultureInfo.InvariantCulture, "Property '{0}' has a default value of a type incompatible with the type of the property.", PropertyName));
}
}
}
}
else
{
Persistence = ConfigurationPersistenceActions.LoadAndSave;
}
if (!Persistence.HasFlag(ConfigurationPersistenceActions.LoadOnly) && !HasDefaultValue)
{
var propertyName = $"[{propertyInfo.DeclaringType.Namespace}.{propertyInfo.DeclaringType.Name}].{propertyInfo.Name}";
throw new InvalidPropertyException(propertyName,
$"'ConfigurationValue' attribute on property \"{propertyName}\" specifies that persistence should only save or ignore values (not load), but no default value is provided.");
}
}
/// <summary>
/// Initializes a new instance of the <see cref="ConfigurationObjectBase{TInterface}" /> class. This is the
/// interface used when creating the root instance for the service collection.
/// </summary>
/// <param name="propertyDef">
/// The definition of the property defined by this object. This can be <see lang="null" /> if this object is
/// the root of the hierarchy.
/// </param>
/// <param name="configurationRoot">
/// The configuration root from which to read and write values.
/// </param>
/// <param name="parent">
/// The parent object to which this one belongs. <see langword="null" /> if this is a root object.
/// </param>
/// <param name="settings">
/// The settings used to control how configuration objects are created and the features they support.
/// </param>
/// <param name="validators">
/// The validators that can be applied to configuration objects of this type.
/// </param>
protected ConfigurationObjectBase(IPropertyDef?propertyDef, IConfigurationRoot configurationRoot, IConfigurationParent parent, ConfigurationObjectSettings settings, IEnumerable <IConfigurationObjectValidator <TInterface> > validators) : base(propertyDef,
ServiceCollectionExtensions.GetConfigurationObjectDefinition(typeof(TInterface), settings), configurationRoot, parent)
{
_validators = validators?.ToArray() ?? Array.Empty <IConfigurationObjectValidator <TInterface> >();
DisablePropertyChangedEvents();
try
{
foreach (var value in Values)
{
if (value.PropertyDef.HasDefaultValue)
{
value.Value = value.PropertyDef.DefaultValue;
value.Saved();
}
}
}
finally
{
EnablePropertyChangedEvents();
Validate();
}
}
