private static object Aggregate <T>(IQueryable <T> queryable, IEnumerable <Aggregator> aggregates)
{
if (aggregates != null && aggregates.Any())
{
var objProps = new Dictionary <DynamicProperty, object>();
var groups = aggregates.GroupBy(g => g.Field);
Type type = null;
foreach (var group in groups)
{
var fieldProps = new Dictionary <DynamicProperty, object>();
foreach (var aggregate in group)
{
var prop = typeof(T).GetProperty(aggregate.Field);
var param = Expression.Parameter(typeof(T), "s");
var selector = aggregate.Aggregate == "count" && (Nullable.GetUnderlyingType(prop.PropertyType) != null)
? Expression.Lambda(Expression.NotEqual(Expression.MakeMemberAccess(param, prop), Expression.Constant(null, prop.PropertyType)), param)
: Expression.Lambda(Expression.MakeMemberAccess(param, prop), param);
var mi = aggregate.MethodInfo(typeof(T));
if (mi == null)
{
continue;
}
var val = queryable.Provider.Execute(Expression.Call(null, mi,
aggregate.Aggregate == "count" && (Nullable.GetUnderlyingType(prop.PropertyType) == null)
? new[] { queryable.Expression }
: new[] { queryable.Expression, Expression.Quote(selector) }));
fieldProps.Add(new DynamicProperty(aggregate.Aggregate, typeof(object)), val);
}
type = DynamicClass.CreateType(fieldProps.Keys.ToList());
var fieldObj = Activator.CreateInstance(type);
foreach (var p in fieldProps.Keys)
{
type.GetProperty(p.Name).SetValue(fieldObj, fieldProps[p], null);
}
objProps.Add(new DynamicProperty(group.Key, fieldObj.GetType()), fieldObj);
}
type = DynamicClass.CreateType(objProps.Keys.ToList());
var obj = Activator.CreateInstance(type);
foreach (var p in objProps.Keys)
{
type.GetProperty(p.Name).SetValue(obj, objProps[p], null);
}
return(obj);
}
else
{
return(null);
}
}
public static Type CreateType(IList <DynamicProperty> properties, bool createParameterCtor)
{
return(DynamicClassFactory.CreateType(properties, createParameterCtor));
//return ClassFactory.Instance.CreateType(properties);
}
