[josm-dev] OSM export incompatibilities between JOSM and Merkaartor

[Frederik Ramm]

Hi,

Chris Browet wrote:
> in http://trac.openstreetmap.org/ticket/1163, a user complains 
> rightfully that the OSM exports from JOSM and Merkaartor are 
> incompatibles, due to the fact that JOSM is using pure numeric IDs while 
> Merkaartor is using text GUID for not-yet-uploaded objects.

If an object is newly created, it will have a negative id.

Also, an "action" attribute is added that either has a value of "modify" 
(for newly created or modified objects), or "delete" (for deleted 
objects). JOSM does not use the "visible" attribute to signal deletions.

So:

* negative id + action=modify: newly created
* positive id + action=modify: modified
* positive id + action=delete: deleted

> I'll internally generate Merkaartor IDs if I detect JOSM IDs.
> Could you please tell me what is the "flag" to detect not-yet-uploaded 
> in your pattern?
> 
> Maybe you could do the same in JOSM if you have text ID's starting with "{"?

I don't want to sound too patronising but until now I thought that the 
way JOSM does it was a kind of established standard (which is, to the 
best of my knowledge, also shared by bulk uploaders, i.e. you can use a 
JOSM-saved file and throw it to a bulk uploader and it will all turn out 
nicely).

Yes we could support text IDs for new objects when loading a file (how 
would we detect deleted/modified objects?) but unless there is a 
compelling reason for using them, could you not just drop the concept of 
text IDs altogether? Would that not also simplify your internal data 
structures (of which I have no detailed knowledge)?

If there *is* a compelling reason for having text IDs, then I'd 
seriously consider changing over to these in JOSM and in existing bulk 
uploaders so we all speak the same language.

I'm setting a Cc/F'up to josm-dev.

Bye
Frederik

-- 
Frederik Ramm  ##  eMail frederik at remote.org  ##  N49°00'09" E008°23'33"