/// <summary>
/// Initializes a new instance of the <see cref="PublishedModelFactory" /> class with types.
/// </summary>
/// <param name="types">The model types.</param>
/// <param name="publishedValueFallback"></param>
/// <remarks>
/// <para>
/// Types must implement <c>IPublishedContent</c> and have a unique constructor that
/// accepts one IPublishedContent as a parameter.
/// </para>
/// <para>To activate,</para>
/// <code>
/// var types = TypeLoader.Current.GetTypes{PublishedContentModel}();
/// var factory = new PublishedContentModelFactoryImpl(types);
/// PublishedContentModelFactoryResolver.Current.SetFactory(factory);
/// </code>
/// </remarks>
public PublishedModelFactory(IEnumerable <Type> types, IPublishedValueFallback publishedValueFallback)
{
var modelInfos = new Dictionary <string, ModelInfo>(StringComparer.InvariantCultureIgnoreCase);
var modelTypeMap = new Dictionary <string, Type>(StringComparer.InvariantCultureIgnoreCase);
foreach (Type type in types)
{
// so... the model type has to implement a ctor with one parameter being, or inheriting from,
// IPublishedElement - but it can be IPublishedContent - so we cannot get one precise ctor,
// we have to iterate over all ctors and try to find the right one
ConstructorInfo?constructor = null;
Type? parameterType = null;
foreach (ConstructorInfo ctor in type.GetConstructors())
{
ParameterInfo[] parms = ctor.GetParameters();
if (parms.Length == 2 && typeof(IPublishedElement).IsAssignableFrom(parms[0].ParameterType) &&
typeof(IPublishedValueFallback).IsAssignableFrom(parms[1].ParameterType))
{
if (constructor != null)
{
throw new InvalidOperationException(
$"Type {type.FullName} has more than one public constructor with one argument of type, or implementing, IPublishedElement.");
}
constructor = ctor;
parameterType = parms[0].ParameterType;
}
}
if (constructor == null)
{
throw new InvalidOperationException(
$"Type {type.FullName} is missing a public constructor with one argument of type, or implementing, IPublishedElement.");
}
PublishedModelAttribute?attribute = type.GetCustomAttribute <PublishedModelAttribute>(false);
var typeName = attribute == null ? type.Name : attribute.ContentTypeAlias;
if (modelInfos.TryGetValue(typeName, out ModelInfo? modelInfo))
{
throw new InvalidOperationException(
$"Both types '{type.AssemblyQualifiedName}' and '{modelInfo.ModelType?.AssemblyQualifiedName}' want to be a model type for content type with alias \"{typeName}\".");
}
// have to use an unsafe ctor because we don't know the types, really
Func <object, IPublishedValueFallback, object> modelCtor =
ReflectionUtilities.EmitConstructorUnsafe <Func <object, IPublishedValueFallback, object> >(constructor);
modelInfos[typeName] = new ModelInfo {
ParameterType = parameterType, ModelType = type, Ctor = modelCtor
};
modelTypeMap[typeName] = type;
}
_modelInfos = modelInfos.Count > 0 ? modelInfos : null;
_modelTypeMap = modelTypeMap;
_publishedValueFallback = publishedValueFallback;
}
