/// <summary>
/// Invokes proxy methods which return a value.
/// </summary>
/// <typeparam name="T">The return type of the method being invoked.</typeparam>
/// <param name="args">The arguments to pass to the method.</param>
/// <returns>The return value of the default proxy method.</returns>
/// <remarks>This method will invoke methods on all of the proxy objects, but will return
/// the result of the invocation on the default object.
/// </remarks>
protected T ProxyInvoke <T>(params object[] args)
{
if (objects.Count == 0)
{
return(default(T));
}
StackTrace trace = new StackTrace();
StackFrame frame = trace.GetFrame(1);
MethodInfo method = frame.GetMethod() as MethodInfo;
ProxyAttributeCollection attributes = GetAttributes(method);
bool first = true;
T result = default(T);
foreach (object invoke in objects)
{
ProxyTypeBindingAttribute binding = attributes.GetTypeBinding(invoke);
MemberInfoAccessor accessor = binding.GetTargetAccessor(typeof(T), args);
if (first)
{
result = (T)accessor.Get(invoke, args);
first = false;
}
else
{
accessor.Get(invoke, args);
}
}
return(result);
}
/// <summary>
/// Gets the <see cref="ProxyAttributeCollection"/> for a given <see cref="MethodInfo"/>.
/// </summary>
/// <param name="method">The method to get the proxy attributes for.</param>
/// <returns>The collection of attributes for the given method as
/// revealed by reflection of the method's attributes.
/// </returns>
private ProxyAttributeCollection GetAttributes(MethodInfo method)
{
if (!attributes.ContainsKey(method))
{
ProxyAttributeCollection collection = ReflectMethod(method);
attributes.Add(method, collection);
}
return(attributes[method]);
}
/// <summary>
/// Performs the get operation on the first object in the list of proxy objects (the default object).
/// </summary>
/// <typeparam name="T">The type to cast the return value as.</typeparam>
/// <param name="args">The indices to pass to the get method.</param>
/// <returns>The result of executing a get operation on the default proxy object, or the default value of T
/// if there are no proxy objects.
/// </returns>
public T ProxyGet <T>(params object[] args)
{
if (objects.Count == 0)
{
return(default(T));
}
StackTrace trace = new StackTrace();
StackFrame frame = trace.GetFrame(1);
MethodInfo method = frame.GetMethod() as MethodInfo;
ProxyAttributeCollection attributes = GetAttributes(method);
ProxyTypeBindingAttribute binding = attributes.GetTypeBinding(objects[0]);
MemberInfoAccessor accessor = binding.GetTargetAccessor(typeof(T), args);
return((T)accessor.Get(objects[0], args));
}
/// <summary>
/// Invokes proxy methods which do not return a value.
/// </summary>
/// <param name="args">The arguments to pass to the method.</param>
protected void ProxyInvoke(params object[] args)
{
if (objects.Count == 0)
{
return;
}
StackTrace trace = new StackTrace();
StackFrame frame = trace.GetFrame(1);
MethodInfo method = frame.GetMethod() as MethodInfo;
ProxyAttributeCollection attributes = GetAttributes(method);
foreach (object invoke in objects)
{
ProxyTypeBindingAttribute binding = attributes.GetTypeBinding(invoke);
MemberInfoAccessor accessor = binding.GetTargetAccessor(typeof(void), args);
accessor.Get(invoke, args);
}
}
/// <summary>
/// Performs the set operation on all proxy objects.
/// </summary>
/// <param name="value">The value to set on the proxy objects.</param>
/// <param name="args">The indices of the set operation.</param>
protected void ProxySet(object value, params object[] args)
{
if (objects.Count == 0)
{
return;
}
StackTrace trace = new StackTrace();
StackFrame frame = trace.GetFrame(1);
MethodInfo method = frame.GetMethod() as MethodInfo;
ProxyAttributeCollection attributes = GetAttributes(method);
foreach (object invoke in objects)
{
ProxyTypeBindingAttribute binding = attributes.GetTypeBinding(invoke);
object[] argsWithValue = new object[args.Length + 1];
argsWithValue[0] = value;
Array.Copy(args, 0, argsWithValue, 1, args.Length);
MemberInfoAccessor accessor = binding.GetTargetAccessor(typeof(void), argsWithValue);
accessor.Set(invoke, value, args);
}
}
/// <summary>
/// Performs reflection on a method in order to determine which methods on proxy objects
/// the method stub is bound to.
/// </summary>
/// <param name="method">The method to reflect over.</param>
/// <returns>The collection of attributes about the method.</returns>
private ProxyAttributeCollection ReflectMethod(MethodInfo method)
{
ProxyAttributeCollection collection = new ProxyAttributeCollection(method);
// get the information that is applied directly to the method
object[] typeBindings = method.GetCustomAttributes(typeof(ProxyTypeBindingAttribute), true);
foreach (ProxyTypeBindingAttribute attribute in typeBindings)
{
collection.AddTypeBinding(attribute);
}
// if the method is a get or set method on a property, also get the attributes applied to the property
if (MemberInfoAccessor.IsGetMethod(method) || MemberInfoAccessor.IsSetMethod(method))
{
PropertyInfo propertyInfo = MemberInfoAccessor.GetProperty(method);
object[] moreBindings = propertyInfo.GetCustomAttributes(typeof(ProxyTypeBindingAttribute), true);
foreach (ProxyTypeBindingAttribute attribute in moreBindings)
{
collection.AddTypeBinding(attribute);
}
}
return(collection);
}
