public List <Criterion> Extract()
{
var result = new List <Criterion>();
foreach (var ex in GetUnitExpressions(Criteria.Body))
{
var condition = Criterion.From(ex);
if (condition == null || (condition as BinaryCriterion)?.IsConvertedCompletely == false)
{
if (ThrowOnNonConversion)
{
throw new Exception("Failed to extract a criterion from expression: " + ex);
}
NotConverted.Add(ex);
}
result.Add(condition);
}
return(result);
}
private static Criterion CreateCriterion(MethodCallExpression expression)
{
return(Criterion.From(expression, throwOnError: false));
}
internal static Criterion CreateCriterion(Expression expression)
{
var binary = expression as BinaryExpression;
if (binary != null)
{
var member = binary.Left as MemberExpression;
if (member != null)
{
var property = GetPropertyExpression(member);
if (property.IsEmpty())
{
return(null);
}
var value = GetExpressionValue(binary.Right);
value = value?.ToString();
return(new Criterion(property, ToOperator(binary.NodeType), value));
}
else if (binary.Left is ParameterExpression)
{
var param = binary.Left as ParameterExpression;
return(new Criterion("ID", ToOperator(binary.NodeType), GetExpressionValue(binary.Right)));
}
else
{
return(null);
}
}
var unary = expression as UnaryExpression;
if (unary != null)
{
if (unary.NodeType != ExpressionType.Not)
{
return(null);
}
var member = unary.Operand as MemberExpression;
if (member == null)
{
return(null);
}
var property = GetPropertyExpression(member);
if (property.IsEmpty())
{
return(null);
}
return(new Criterion(property, FilterFunction.Is, false));
}
// Boolean property:
if (expression is MemberExpression && expression.NodeType == ExpressionType.MemberAccess)
{
var member = expression as MemberExpression;
var property = GetPropertyExpression(member);
if (property.IsEmpty())
{
return(null);
}
if (property == "HasValue")
{
property = (member.Expression as MemberExpression)?.Member?.Name;
if (property.IsEmpty())
{
return(null);
}
return(new Criterion(property, FilterFunction.IsNot, value: null));
}
if (((member as MemberExpression).Member as PropertyInfo).PropertyType != typeof(bool))
{
return(null);
}
// Only one property level is supported:
return(new Criterion(property, FilterFunction.Is, true));
}
// Method call
var methodCall = expression as MethodCallExpression;
if (methodCall != null)
{
return(Criterion.From(methodCall, throwOnError: false));
}
return(null);
}