add support of Date type.

[sbernard31]

Maybe I'm wrong but It seems to me currently there is no support for Date type.

Is it something planned to support date like defined in RFC7049§2.4.1 ?

[peteroupc]

The methods CBORObject.FromObject and .ToObject already support converting CBOR objects to and from java.lang.Date.

[sbernard31]

Good to know. Thx @peteroupc 🙏

[sbernard31]

(Just an idea, maybe a method asDate() could make this more visible. 🤔)

[sbernard31]

I see the default way to encoding date is to use String (tag 0)
Any reason why choosing this one instead of the timestamp one (tag 1) which is maybe a bit more straightforward ?

[sbernard31]

I guess I maybe find a bug (I'm not sure at all)
I tried to encode a Date using number instead of string and so I use :

obj = CBORObject.FromObjectAndTag(date.getTime(), 1);

instead of

obj = CBORObject.FromObject(date);

Tell me if I'm wrong.

If do that, I face an issue because this can not be decoded using :

Date date = obj.ToObject(Date.class);

I face :

com.upokecenter.cbor.CBORException: Not a finite number
	at com.upokecenter.cbor.CBORDateConverter.FromCBORObject(CBORDateConverter.java:33)
	at com.upokecenter.cbor.PropertyMap.TypeToObject(PropertyMap.java:584)
	at com.upokecenter.cbor.CBORObject.ToObject(CBORObject.java:1637)
	at com.upokecenter.cbor.CBORObject.ToObject(CBORObject.java:1301)

I guess maybe the issue is in :

static boolean IsNumber(CBORObject o) {
      if (IsUntaggedInteger(o)) {
        return true;
      } else if (!o.isTagged() && o.getType() == CBORType.FloatingPoint) {
        return true;
 ... ...

In my case this is a taggedInteger and so isNumber return false.
(tested with 4.0.0 and 4.2.0)

[peteroupc]

Yes, this should have been supported better: "If the type is DateTime (or Date in Java) , returns a date/time object if the CBOR object's outermost tag is 0 or 1."

[sbernard31]

This is pretty much implemented in CBORDateConverter but it seems there is a bug. 😬

Not directly linked to this bug, but my 2 cents about improving Date API.
I think maybe adding those method would be great :

CBORObject.isDate();
CBORObject.asDate();
CBORObject.fromDateAsString(date); 
CBORObject.fromDateAsTimestamp(date); 

I think CBORObject.fromObject((Date) date); should maybe encode Date as timestamp by default as I suppose this is easier for a constraint device to deal with a timestamp rather than decode a string Date format.

(Just in case I begin some comparison between Jackson and CBOR-JAVA : eclipse-leshan/leshan#939)

[peteroupc]

I have updated this repository to fix the bug in CBORDateConverter.

The suggestion in your last comment might not be implemented until the next major version (which might not happen in a while) for backward compatibility reasons. (To be clear, the next version I expect to release is version 4.3, which is a minor version.)

[sbernard31]

The suggestion in your last comment might not be implemented until the next major version (which might not happen in a while) for backward compatibility reasons.

No problem, there is no urgency for this. (This is just some improvement ideas)

I have updated this repository to fix the bug in CBORDateConverter.

Thx 🙏 for your time !

[sbernard31]

Should we close this issue and I create a dedicated one for "date API improvement" or we just keep this one open ?

[peteroupc]

Now the CBORDateConverter was made public and expanded.

This issue can now be closed.