public FilterGroup(FilterGroupOperation groupOperation, QueryToken?token, List <Filter> filters)
{
this.GroupOperation = groupOperation;
this.Token = token;
this.Filters = filters;
}
public QueryFilterGroup(FilterGroupOperation operation)
{
Operation = operation;
}
public QueryFilterGroup(FilterGroupOperation operation, QueryFilterElement[] filterElements)
{
Operation = operation;
FilterElements = filterElements;
}
private static Expression GetFilterGroupExpression <T>(IList <QueryFilter> filters, ParameterExpression param, FilterGroupOperation operation = FilterGroupOperation.And)
{
Expression expression = null;
foreach (QueryFilter filter in filters)
{
Expression subExpression = null;
if (filter is QueryFilterGroup filterGroup)
{
subExpression = GetFilterGroupExpression <T>(filterGroup.FilterElements, param, operation);
}
else
{
subExpression = GetFilterElementExpression <T>((QueryFilterElement)filter, param);
}
switch (operation)
{
case FilterGroupOperation.And:
expression = expression == null ? subExpression : Expression.AndAlso(expression, subExpression);
break;
case FilterGroupOperation.Or:
expression = expression == null ? subExpression : Expression.OrElse(expression, subExpression);
break;
default: throw new ArgumentOutOfRangeException();
}
}
return(expression);
}