json net leading zeros (disable base-cast)

by

Since leading zeros are disallowed by the the JSON standard, it would seem Newtonsoft decided to implement parsing of JavaScript-style octal numbers as an extension to the standard, see Json.NET 3.5 Release 7 – Biggest Release Ever Edition. This behavior is currently hardcoded into JsonTextReader.ParseReadNumber(ReadType readType, char firstChar, int initialPosition) with no option to force strict conformance to the standard (i.e. throw an exception on a leading zero), as is stated in:

As a workaround, you could use JavaScriptSerializer to parse to an intermediate dynamic object, then re-serialize that to an intermediate JToken, then deserialize that JToken to your final class:

var json = @"{ ""number"":010 }";

var root = JToken.FromObject(new JavaScriptSerializer().DeserializeObject(json)).ToObject<RootObject>();

if (root.Number != 10)
{
    throw new InvalidOperationException();
}

Using

class RootObject
{
    public int Number { get; set; }
}

You could also re-serialize to an intermediate JSON string, but re-serializing to an intermediate JToken should be more efficient for larger objects.

(Switching to DataContractJsonSerializer or JavaScriptSerializer are also options if you do not need the full functionality of Json.NET, since both will silently parse an integer with a leading zero in base 10.)

Another option would be to fork your own version of JsonTextReader and all associated utilities, and fix the logic of JsonTextReader.ParseReadNumber() to throw a JsonReaderException when nonBase10 is true. Unfortunately, forking your own JsonTextReader may require substantial ongoing maintenance, since you will also need to fork any and all Newtonsoft utilities used by the reader (there are many) and update them to any breaking changes in the original library. You could also vote up or comment on enhancement request #646 requesting strict integer parsing.

Why did Newtonsoft implement parsing of numbers in octal syntax? My speculation is that they added this functionality to handle numbers formatted in the JavaScript syntax for integer literals:

Integers

Integers can be expressed in decimal (base 10), hexadecimal (base 16),
octal (base 8) and binary (base 2).

  • Decimal integer literal consists of a sequence of digits without a leading 0 (zero).
  • Leading 0 (zero) on an integer literal, or leading 0o (or 0O) indicates it is in octal. Octal integers can include only the digits
    0-7.

  • Leading 0x (or 0X) indicates hexadecimal. Hexadecimal integers can include digits (0-9) and the letters a-f and A-F.

  • Leading 0b (or 0B) indicates binary. Binary integers can include digits only 0 and 1.

More Related Contents:

  1. parse JSON using json.net c# [closed]
  2. How can I parse JSON with C#?
  3. Deserializing JSON data to C# using JSON.NET
  4. Can I specify a path in an attribute to map a property in my class to a child property in my JSON?
  5. Casting interfaces for deserialization in JSON.NET
  6. How to show the “paste Json class” in visual studio 2012 when clicking on Paste Special?
  7. “Self Referencing Loop Detected” exception with JSON.Net
  8. Parsing JSON Object with variable properties into strongly typed object
  9. Deserialize json array stream one item at a time
  10. How to Deserialize JSON data?
  11. Set default global json serializer settings
  12. How do I enumerate through a JObject?
  13. How to make JSON.Net serializer to call ToString() when serializing a particular type?
  14. Newtonsoft Json.Net serialize JObject doesn’t ignore nulls, even with the right settings
  15. JSON.net serialize directly from oledbconnection
  16. multiple JsonProperty Name assigned to single property
  17. Json.NET custom serialization with JsonConverter – how to get the “default” behavior
  18. Why are some members missing when trying to print an object by serializing to JSON?
  19. Send JSON via POST in C# and Receive the JSON returned?
  20. Deserializing heterogenous JSON array into covariant List using Json.NET
  21. JSON deserialization – Map array indices to properties with JSON.NET
  22. Deserialize specific enum into system.enum in Json.Net
  23. JSON.NET serialize JObject while ignoring null properties
  24. How do I get formatted and indented JSON in .NET using C#?
  25. How to deserialize a property with a dash (“-”) in its name with NewtonSoft JsonConvert?
  26. Deserialize JSON recursively to IDictionary [duplicate]
  27. Streaming large list of data as JSON format using Json.net
  28. Merge two Json.NET arrays by concatenating contained elements
  29. Extract data from Json string
  30. How do I parse a JSON object in C# when I don’t know the key in advance?

Leave a Comment