private string GetCurrentUserId()
{
// Grab the current user's username
var changedByUserName = this.GetCurrentUserName();
// Set the "Id" variable to the name of the primary key "Id" column as defined in the config
var Id = loggingConfig_User.Id;
// Get the user type defined in the config
Type userType = Type.GetType(loggingConfig_User.UserTypeFullName + ", " + loggingConfig_User.UserTypeAssemblyName);
// Create a generic expression in order to search for the user, matching the "UserName" column defined in the config
const string methodSignature =
"System.Linq.Expressions.Expression`1[TDelegate] Lambda[TDelegate]" +
"(System.Linq.Expressions.Expression, System.Linq.Expressions.ParameterExpression[])";
MethodInfo expression_method_Lambda = typeof(Expression).GetMethods().Single(m => m.ToString() == methodSignature);
var func_type = typeof(Func <,>).MakeGenericType(userType, typeof(bool));
MethodInfo expression_generic_Lambda = expression_method_Lambda.MakeGenericMethod(func_type);
var param = Expression.Parameter(userType, "p");
var exp = expression_generic_Lambda.Invoke(null, new object[] {
Expression.Equal(
Expression.Property(param, loggingConfig_User.UserName),
Expression.Constant(changedByUserName)
),
new [] { param }
});
// Make a generic call to repo.Single using the recently acquired user type and expression
MethodInfo repo_method_Single = repo.GetType().GetMethod("Single");
MethodInfo repo_generic_Single = repo_method_Single.MakeGenericMethod(userType);
var user = repo_generic_Single.Invoke(repo, new object[] { exp });
if (user == null)
{
return("User: "******"\"" + changedByUserName + "\"" + " not found.");
}
// Get the primary key of the user return it
var userIdProp = userType.GetProperty(Id);
return(userIdProp.GetValue(user, null).ToString());
}