[OSM-dev] [OSM-talk] Getting historic information about usage of a node

Peter Körner osm-lists at mazdermind.de
Wed Sep 16 00:49:02 BST 2009


I'm on dev just for about one hour so I didn't get your mail and my 
problem is a little different. I'm working an very similar tool than you.

I'm currently building the backend of an app that shows changesets in a 
human readable way. On the long run this will become a revert tool. But 
please don't stop your work now, plurality is a very good thing!

As the changesets contains the version i'm not running into the same 
problem as you but mine is a similar one. As this is a difficult thing 
i'd like to show it in a more visual way.

Take a look here:
http://imagebin.ca/view/iF7Ic9Yf.html

We Way #10 which consists of Nodes #20, #30, #40 and #50.

In the upper part we see Changeset #5 in which node #50 is moved.
In the lower part we see Changeset #6 in which node #50 is deleted.

Now so. want's to inspect (or revert) Changeset #5. A Tool using the API 
sees that node #50 was moved and now wants to tell the user to what 
extent this changed the geometry of ways and show him a map with the 
original and the new geometry of these ways.

But because Node #50 was deleted after Changeset #5 there is *no* way to 
fetch the ways this node was in. Same would happen if Way #10 would get 
deleted - the GET /node/#id/ways call just does not spit out any 
historic information. What we need would be a

    GET /node/#id/#version/ways

But i don't think this can go into the api without a major change..

Peter

Ian Dees schrieb:
> On Tue, Sep 15, 2009 at 5:56 PM, Peter Körner <osm-lists at mazdermind.de 
> <mailto:osm-lists at mazdermind.de>> wrote:
> 
> 
> 
>     Am I missing sth.? Can you think of any trick to get this information?
> 
> 
> Good timing, Peter. I believe we were talking about this exact 
> limitation in the API on the dev@ list [0]. If the issue is the same, 
> perhaps you could throw your usecase into the discussion.
> 
> [0]  http://lists.openstreetmap.org/pipermail/dev/2009-September/017017.html




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