So my colleague Mark Jaroski added the boundaries of Paris’ 19 arrondissements (districts) to OSM a while back. This is useful, accurate administrative information, and has the added benefit of letting us at Wikitravel Press easily crop the map data into single-arrondissment sections for printing.
But alas, now somebody has gone and deleted them.
Is there any way to find out who did it and why?
Is there any way to restore the data on the OSM side?
If we have an XML dump of the data with the paths in question, is there any way to re-inject it into OSM?
Now, I can see why somebody might want to do this. Having all-inclusive boundaries like this will cause any program which is rendering them all to effectively render each boundary twice. However it is useful to have these inclusive boundaries to work with.
If I could find a way to tag them which would prevent them from rendering in potlatch, and which would be acceptable then I would re-upload them.
Hmm, Skywave is a very experienced and active Dutch mapper. You should try to contact him using the messaging options on the ‘www’ site and try to find out why he ‘disabled’ the boundaries. Also, if you say that your boundaries are duplicates from already existing boundaries then why don’t you use those boundaries?
I didn’t use them because I needed something to completely enclose the area. Knitting the existing boundary fragments together isn’t something that’s easily accomplished in XSL, so if possible I’d like to keep the enclosing ones, but in a way which doesn’t annoy people who prefer the fragments.
You should really ask the person who deleted it why they deleted, all the rest of us can really do is speculate as to why.
It could be a concern about the source of the data and if it can legally be added to OSM.
Duplicate data makes maintenance harder. All copies need to be kept in sync when changes are made.
Long ways can be a problem as when someone downloads the data for an area all the ways that have a node within that area and all the nodes these ways reference are downloaded. Long ways mean more data so the server takes longer to prepare the data, the data takes longer to download and the client software might get struggle under the load. As a result long ways tend to get split into smaller fragments.
Duplicate data will be merged/deleted, long ways will be split. Your tools need to deal with that if they want to use data from OSM directly.
Go to Potlatch for the area in question. Press ‘U’ (undelete). This will show you deleted ways, in red. Select the one you want to undelete, and click the padlock to unlock it. Deselect and it’ll be saved.
Yes when you delete something in Openstreetmap the only thing that happens is that the way will be marked as not visible, the same goes for the nodes. When node references and tags are removed and the object is saved under a new version.