private ConstructorExpression BuildConstructorExpression(Type concreteType, DependencyChain chain)
{
// If the concrete type is a generic type definition, we cannot invoke it's constructor.
// We need to construct the type using the generic arguments defined on the requested type from the dependency chain.
if (concreteType.IsGenericTypeDefinition)
{
concreteType = concreteType.MakeGenericType(chain.Type.GetGenericArguments());
}
// Order by constructors with the most amount of parameters.
var constructors = concreteType.GetConstructors();
var expression = new ConstructorExpression();
// Don't bother ordering if only 1 constructor is present.
if (constructors.Length == 1)
{
return(BuildConstructor(constructors[0], chain));
}
var constructor = constructors
.OrderByDescending(x => x.GetParameters().Length)
.FirstOrDefault();
// No valid public constructors were found.
if (constructor == null)
{
throw new MissingConstructorException(concreteType);
}
return(BuildConstructor(constructor, chain));
}
private ConstructorExpression BuildConstructor(ConstructorInfo constructor, DependencyChain chain)
{
var parameters = constructor.GetParameters();
var expression = new ConstructorExpression
{
ParameterChains = new DependencyChain[parameters.Length]
};
// Iterate through all the parameters in the constructor.
for (var i = 0; i < parameters.Length; i++)
{
// Create a new DependencyChain node for the parameter type.
var childChain = new DependencyChain(parameters[i].ParameterType, chain);
expression.ParameterChains[i] = childChain;
}
expression.BuildExpression(constructor);
return(expression);
}
