public static NhFilterDefinition Concat(NhFilterDefinition left, string @operator, NhFilterDefinition right)
{
return(new NhFilterDefinition()
{
Parameters = left.Parameters.Union(right.Parameters).ToDictionary(c => c.Key, c => c.Value),
Condition = $"({left.Condition} {@operator} {right.Condition})"
});
}
private static NhFilterDefinition FromBinaryExpression(ref int i, BinaryExpression binaryExpression)
{
var left = Recurse(ref i, binaryExpression.Left, isBinary: true);
var right = Recurse(ref i, binaryExpression.Right);
var operand = NodeTypeToString(binaryExpression.NodeType, right?.Condition == "NULL");
return(NhFilterDefinition.Concat(left, operand, right));
}
public static NhFilterDefinition FromUnary(string @operator, NhFilterDefinition definition)
{
return(new NhFilterDefinition()
{
Parameters = definition.Parameters,
Condition = $"({@operator} {definition.Condition})"
});
}
private static NhFilterDefinition FromMethodCallExpression(ref int i, MethodCallExpression methodCallExpression)
{
if (methodCallExpression.Method == typeof(string).GetMethod("Contains", new[] { typeof(string) }))
{
return(NhFilterDefinition.Concat(
Recurse(ref i, methodCallExpression.Object), "LIKE",
Recurse(ref i, methodCallExpression.Arguments[0], prefix: "%", postfix: "%")
));
}
if (methodCallExpression.Method == typeof(string).GetMethod("StartsWith", new[] { typeof(string) }))
{
return(NhFilterDefinition.Concat(
Recurse(ref i, methodCallExpression.Object), "LIKE",
Recurse(ref i, methodCallExpression.Arguments[0], postfix: "%")
));
}
if (methodCallExpression.Method == typeof(string).GetMethod("EndsWith", new[] { typeof(string) }))
{
return(NhFilterDefinition.Concat(
Recurse(ref i, methodCallExpression.Object), "LIKE",
Recurse(ref i, methodCallExpression.Arguments[0], prefix: "%")
));
}
if (methodCallExpression.Method.Name == "Contains")
{
Expression collection;
Expression property;
if (methodCallExpression.Method.IsDefined(typeof(ExtensionAttribute)) && methodCallExpression.Arguments.Count == 2)
{
collection = methodCallExpression.Arguments[0];
property = methodCallExpression.Arguments[1];
}
else if (!methodCallExpression.Method.IsDefined(typeof(ExtensionAttribute)) && methodCallExpression.Arguments.Count == 1)
{
collection = methodCallExpression.Object;
property = methodCallExpression.Arguments[0];
}
else
{
throw new Exception("Unsupported method call: " + methodCallExpression.Method.Name);
}
var values = (IEnumerable)GetValue(collection);
return(NhFilterDefinition.Concat(Recurse(ref i, property), "IN", NhFilterDefinition.FromCollection(ref i, values, GetNhType(values.GetType()))));
}
if (methodCallExpression.Type == typeof(string))
{
return(NhFilterDefinition.FromParameter(i++, GetValue(methodCallExpression), null));
}
throw new Exception("Unsupported method call: " + methodCallExpression.Method.Name);
}
private static NhFilterDefinition FromConstantExpression(ref int i, string prefix, string postfix, ConstantExpression constantExpression, bool isMember)
{
var value = constantExpression.Value;
if (value == null && !isMember)
{
return(NhFilterDefinition.FromHql("NULL"));
}
return(NhFilterDefinition.FromParameter(i++, constantExpression.Value, GetNhType(constantExpression.Type)));
}
private static NhFilterDefinition FromMemberExpression(ref int i, Expression expression, string prefix, string postfix, MemberExpression memberExpression, bool isBinary = false)
{
if (IsMethodOrConstant(memberExpression))
{
return(FromConstantExpression(ref i, prefix, postfix, Expression.Constant(GetValue(memberExpression), memberExpression.Type), true));
}
if (memberExpression.Expression is MemberExpression)
{
return(FromMemberExpression(ref i, memberExpression, prefix, postfix, memberExpression.Expression as MemberExpression, isBinary));
}
if (memberExpression.Member is PropertyInfo)
{
var property = (PropertyInfo)memberExpression.Member;
var colName = property.Name;
if (!isBinary && memberExpression.Type == typeof(bool))
{
return(NhFilterDefinition.Concat(NhFilterDefinition.FromCondition(colName), "=", NhFilterDefinition.FromParameter(i++, true, GetNhType(memberExpression.Type))));
}
return(NhFilterDefinition.FromCondition(colName));
}
if (memberExpression.Member is FieldInfo)
{
var value = GetValue(memberExpression);
if (value is string)
{
value = prefix + (string)value + postfix;
}
return(NhFilterDefinition.FromParameter(i++, value, GetNhType(memberExpression.Type)));
}
throw new Exception($"Expression does not refer to a property or field: {expression}");
}
private static NhFilterDefinition FromUnaryExpression(ref int i, UnaryExpression unaryExpression)
{
return(NhFilterDefinition.FromUnary(NodeTypeToString(unaryExpression.NodeType), Recurse(ref i, unaryExpression.Operand)));
}
public NhDataFilter(IDataFilter dataFilter, NhFilterDefinition filterDefinition)
{
this.dataFilter = dataFilter;
FilterDefinition = filterDefinition;
}
