public IEnumerable <ValidationResult> Validate(ValidationContext validationContext)
{
var result = new List <ValidationResult>();
if (string.IsNullOrWhiteSpace(FilterExpr))
{
return(result);
}
var reader = new FilterReader(FilterReader.Utf8Encoding.GetBytes(FilterExpr));
if (FilterReaderHelper.TryRead(ref reader, FilterExpr, TargetModelPropertyInfos, out var tokens, out var error))
{
Tokens = tokens;
var parser = new FilterParser(tokens, TargetModelPropertyInfos);
try
{
var node = parser.Parse();
Node = node;
}
catch (FilterException e)
{
result.Add(new ValidationResult(e.Message, new[] { "$filter" }));
}
Validate(Node, result);
}
public static bool TryRead(ref FilterReader reader, string filterExpr, IList <PropertyInfo> propertyInfos, out IList <Token> tokens, out string error)
{
var position = 0;
var retVal = true;
tokens = new List <Token>();
error = null;
try
{
while (true)
{
if (!reader.Read())
{
break;
}
var val = FilterReader.Utf8Encoding.GetString(reader.ValueSpan);
var i = filterExpr.IndexOf(val, position, StringComparison.Ordinal) + 1;
position += val.Length;
switch (reader.TokenType)
{
case FilterTokenType.PropertyName:
{
var propertyName = val.StartsWith((char)FilterConstants.At) ? val.Substring(1) : val;
if (!propertyInfos.Any(x => x.Name.Equals(propertyName, StringComparison.OrdinalIgnoreCase)))
{
throw new FilterException($"不存在的属性: {propertyName}。");
}
tokens.Add(new Token(FilterTokenType.PropertyName, propertyName, i));
break;
}
case FilterTokenType.StartGrouping:
case FilterTokenType.EndGrouping:
case FilterTokenType.UnaryLogicalOperator:
case FilterTokenType.BinaryLogicalOperator:
case FilterTokenType.RelationalOperator:
case FilterTokenType.Number:
case FilterTokenType.True:
case FilterTokenType.False:
case FilterTokenType.Null:
tokens.Add(new Token(reader.TokenType, val, i));
break;
case FilterTokenType.String:
{
var s = val.Substring(1, val.Length - 2);
tokens.Add(new Token(reader.TokenType, s, i));
break;
}
default:
throw new ArgumentOutOfRangeException();
}
}
}
catch (FormatException e)
{
retVal = false;
error = e.Message;
}
return(retVal);
}