/// <summary>
/// Uses the TraceBuilder rules on the provider to generate the parameter bindings.
/// </summary>
/// <param name="methodInfo">The method to analyze.</param>
/// <returns>A list of ParameterMapping representing the desired bundling of parameters.</returns>
private IReadOnlyCollection <ParameterMapping> EvaluateBuilders(MethodInfo methodInfo)
{
var mappings = new List <ParameterMapping>();
var parameters = methodInfo.GetParameters().ToList();
// give a context rule the opportunity to bind
parameters.Add(null);
// get the default name to use for tracing (null if none specified)
var traceAsDefault = methodInfo.GetCustomAttribute <TraceAsAttribute>();
foreach (var parameter in parameters)
{
bool hasRule = false;
// go through the rules
foreach (var builder in _builders.Where(b => b.Matches(methodInfo)))
{
foreach (var value in builder.Values.Where(v => v.Matches(parameter)))
{
hasRule = true;
// if the value is an ignore rule, skip it
if (value.Ignore)
{
continue;
}
// add the parameter value
AddMapping(mappings, parameter, builder.Alias ?? "data", value.Alias ?? builder.Alias ?? "data", value.Converter);
}
}
// if a rule has been applied, then don't add the base value
if (hasRule)
{
continue;
}
if (parameter == null)
{
continue;
}
// if there is a TraceIgnore attribute, then skip this parameter
if (parameter.GetCustomAttribute <TraceIgnoreAttribute>() != null)
{
continue;
}
// we need one parameter per attribute, and at least one per parameter
var attributes = parameter.GetCustomAttributes <TraceAsAttribute>();
if (!attributes.Any())
{
attributes = new TraceAsAttribute[1] {
traceAsDefault ?? new TraceAsAttribute(parameter.Name)
}
}
;
foreach (var attribute in attributes)
{
var traceName = attribute.Name ?? parameter.Name;
var input = Expression.Parameter(parameter.ParameterType);
Expression expression = input;
// if the attribute is a TraceMember, then create an expression to get the member
var traceMember = attribute as TraceMemberAttribute;
if (traceMember != null)
{
expression = Expression.MakeMemberAccess(expression, parameter.ParameterType.GetMember(traceMember.Member).First());
}
// if the attribute is a TraceTransform then validate the usage and use the provided method
// to build an expression to apply to the trace value
var traceTransform = attribute as TraceTransformAttribute;
if (traceTransform != null)
{
var method = traceTransform.GetTransformMethod(input.Type);
if (method == null)
{
var message = String.Format("{0}.GetTransformMethod() returned null.", attribute.GetType().Name);
throw new ArgumentNullException("Method", message);
}
var methodParams = method.GetParameters();
if (methodParams.Length != 1 || method.ReturnType == typeof(void) || !method.IsStatic)
{
var message = String.Format("{0}.GetTransformMethod() should return MethodInfo for a static method with one input parameter and a non-void response type.", attribute.GetType().Name);
throw new ArgumentException(message);
}
if (methodParams[0].ParameterType != input.Type)
{
var message = String.Format(
"{0}.GetTransformMethod() returned MethodInfo for a static method which expects an input type of '{1}' but was applied to a trace parameter of type '{2}'. (trace method name: {3}, parameter name: {4})",
attribute.GetType().Name,
methodParams[0].ParameterType,
input.Type,
methodInfo.Name,
traceName);
throw new ArgumentException(message);
}
expression = Expression.Call(method, input);
}
// if a string format was specified, wrap the expression in a method call
if (!String.IsNullOrWhiteSpace(attribute.Format))
{
var format = Expression.Constant(attribute.Format);
var castAsObject = Expression.Convert(input, typeof(object));
expression = Expression.Call(typeof(String).GetMethod("Format", new Type[] { typeof(string), typeof(object) }), format, castAsObject);
}
// if we did any conversion on the value, then create a lambda function for the conversion
LambdaExpression lambda = null;
if (expression != input)
{
lambda = Expression.Lambda(expression, input);
}
AddMapping(mappings, parameter, traceName, parameter.Name, lambda);
}
}
return(mappings);
}
#endregion
}
/// <summary>
/// Uses the TraceBuilder rules on the provider to generate the parameter bindings.
/// </summary>
/// <param name="methodInfo">The method to analyze.</param>
/// <returns>A list of ParameterMapping representing the desired bundling of parameters.</returns>
private IReadOnlyCollection <ParameterMapping> EvaluateBuilders(MethodInfo methodInfo)
{
var mappings = new List <ParameterMapping>();
var parameters = methodInfo.GetParameters().ToList();
// give a context rule the opportunity to bind
parameters.Add(null);
// get the default name to use for tracing (null if none specified)
var traceAsDefault = methodInfo.GetCustomAttribute <TraceAsAttribute>();
foreach (var parameter in parameters)
{
bool hasRule = false;
// go through the rules
foreach (var builder in _builders.Where(b => b.Matches(methodInfo)))
{
foreach (var value in builder.Values.Where(v => v.Matches(parameter)))
{
hasRule = true;
// if the value is an ignore rule, skip it
if (value.Ignore)
{
continue;
}
// add the parameter value
AddMapping(mappings, parameter, builder.Alias ?? "data", value.Alias ?? builder.Alias ?? "data", value.Converter);
}
}
// if a rule has been applied, then don't add the base value
if (hasRule)
{
continue;
}
if (parameter == null)
{
continue;
}
// if there is a TraceIgnore attribute, then skip this parameter
if (parameter.GetCustomAttribute <TraceIgnoreAttribute>() != null)
{
continue;
}
// we need one parameter per attribute, and at least one per parameter
var attributes = parameter.GetCustomAttributes <TraceAsAttribute>();
if (!attributes.Any())
{
attributes = new TraceAsAttribute[1] {
traceAsDefault ?? new TraceAsAttribute(parameter.Name)
}
}
;
foreach (var attribute in attributes)
{
var traceName = attribute.Name;
// if the attribute is a TraceMember, then create an expression to get the member
LambdaExpression expression = null;
var traceMember = attribute as TraceMemberAttribute;
if (traceMember != null)
{
var input = Expression.Parameter(parameter.ParameterType);
expression = Expression.Lambda(
Expression.MakeMemberAccess(
input,
parameter.ParameterType.GetMember(traceMember.Member).First()),
input);
}
AddMapping(mappings, parameter, traceName, parameter.Name, expression);
}
}
return(mappings);
}
#endregion
}
