public static Expression <Func <T, bool> > ConstructAndExpressionTree <T>(List <ExpressionFilter> filters)
{
if (filters.Count == 0)
{
return(null);
}
ParameterExpression param = Expression.Parameter(typeof(T), "t");
Expression exp = null;
if (filters.Count == 1)
{
exp = ExpressionRetriever.GetExpression <T>(param, filters[0]);
}
else
{
exp = ExpressionRetriever.GetExpression <T>(param, filters[0]);
for (int i = 1; i < filters.Count; i++)
{
exp = Expression.Or(exp, ExpressionRetriever.GetExpression <T>(param, filters[i]));
}
}
return(Expression.Lambda <Func <T, bool> >(exp, param));
}
public static Expression <Func <T, bool> > ConstructAndExpressionTree <T>(List <ExpressionFilter> filters, bool applyAndOpertor)
{
if (filters == null || filters.Count == 0)
{
return(null);
}
// create parameter
ParameterExpression param = Expression.Parameter(typeof(T), "t");
Expression exp = ExpressionRetriever.GetExpression <T>(param, filters[0], filters[0].PropertyType);
for (int i = 1; i < filters.Count; i++)
{
if (applyAndOpertor)
{
exp = Expression.And(exp, ExpressionRetriever.GetExpression <T>(param, filters[i], filters[i].PropertyType));
}
else
{
exp = Expression.Or(exp, ExpressionRetriever.GetExpression <T>(param, filters[i], filters[i].PropertyType));
}
}
return(Expression.Lambda <Func <T, bool> >(exp, param));
}