Overpass API developpement

[Stefan Keller <>]

Hi Roland

Many thanks for your precise instructions. You made me think over
again. Here's what I found with the help of Simon among others:

My goal is to get an opaque fixed length ASCII string. And that are my
design considerations:

* The OSM id alone is not stable enough (as we probably all agree);
and it can represent many concepts (and that's by design in OSM).
* The version no. of the object is needed which makes clear which tags
are (or have been originally) referred to.
* Coordinates are needed, because a change of the geometry does not
increment the version number.

So a stable Permanent-ID could have the following form:

  [N|W|R]<osm_id>#<version>[+|-]<lon>[+|-]<lat>

where osm_id is left-padded with zeros to get 10 chars ("digits"), and
the coordinates have 5 fixed decimal places (which leads to a fixed
length of 33 chars).

Example: "Schloss Kyburg" (Castle Kyburg) has relation 1169711,
version #5 at coordinates 47.4584, 8.74343 which becomes following
Permanent-ID:

  R0001169711#05+47.45840+008.74343

I'm pretty sure a client software can create an Overpass "raw query"
(with "[out:custom];") as you described above.

What do you think?

:Stefan



Am Di., 9. Okt. 2018 um 19:30 Uhr schrieb Roland Olbricht
<>:
>
> Dear Stefan,
>
> > What do you think about extending the overpass-turbo GUI with a copy
> > link as PermanentID [1]?
> > So; given a query entered at overpass-turbo until it "works", one
> > could go to "Export > Query" and could get a PermanentID link?
>
> Thank you for the suggestion.
>
> > [...]  trying to make a pull request).
>
> And for the implementation as well, if this is already done.
>
> I'm not yet sure whether I understand the precise request. What works
> right now is:
>
> a) You can use the share button in Overpass Turbo.
> This produces a short link. That link will work until the link database
> of Overpass Turbo goes out of service. It will always refer to the query.
>
> b) You can use the button export then tab query, to OSM wiki link.
> This allow you to use a page in the wiki as place for the storage.
>
> c) You can get the raw query, via export button then tab data, raw
> query. If you restate that with "[out:custom];" in front then the
> Permanent-ID mechanism is involved. No link database neede. The (without
> question longish) link works directly from where you drop it.
>
> In particular, the concept of the Permanent Id is to link almost always
> to a single object; the disambiguation page is only intended as
> mechanism to fail gracefully. Overpass Turbo is not at all involved in
> the original and existing mechaism.
>
> That said, a couple of intents are imaginable:
>
> 1. Replace the disambiguation page with a landing in Overpass Turbo.
> That is definetly more useful. The difficult task is to deliver a
> helpful landing page design in Overpass Turbo.
>
> 3. Get some kind of export that directly produces a link usable from a
> web page.
>
> 3. Get some kind of export that directly produces something to copy to
> the wiki. This is mostly tricky because it involves templates, and
> templates are a infamous feature to many wiki activists at the moment.
>
> Best regards,
>
> Roland