[Qgis-developer] Adding default OSM backround maps

[Paolo Cavallini]

Hi all,
we have been exploring the possibility of adding default XYZ maps to
QGIS, so to make life far easier for users.
The good news is that the OSM board is quite positive about this.
The not-so-good news is that their (I believe reasonable) requirements
imply some more development from our side.
Is anyone interested in taking this?
Requirements below.
All the best.
===

1. You seem to be using an user agent of "Mozilla/5.0 QGIS/2.18.3". We
strongly recommend that you don't pretend to be a browser by adding the
"Mozilla" bit. OpenStreetMap sees increasing traffic from "fake" user
agents, and it is likely that we will penalise user agents like that at
some point in the future - meaning tiles will still be served, but
slower than to "honest" user agents that don't pretend to be a browser
when they are not. We understand that this is difficult terrain and that
other data sources might actually *require* that you pretend to be a
browser - perhaps per-datasource overrides of the user agent are a
possibility.

2. As you know, OpenStreetMap thrives on contributions by mappers, and
one of the main reasons we make our tiles freely available is the hope
of attracting new contributors. It would be nice if QGIS could do its
part to help us here, by making their users aware that OSM is open for
everyone to contribute. Perhaps a link to
http://www.openstreetmap.org/fixthemap can be placed somewhere in the
layer description or something.

3. Our data is licensed under ODbL 1.0, and our map tiles are CC-BY-SA
2.0. The latter could change at any time; the former is
relatively constant.

The legal consequences of this situation for your users are:

* If they publish an image in which our tiles are visible, they must
attribute OpenStreetMap as the source, and specify that the map image is
CC-BY-SA 2.0, and specify that the data behind it is ODbL 1.0. All these
requirements can be fulfilled in one go by linking to
www.openstreetmap.org/copyright but there is no legal requirement to
link to that page.

* Everyone is allowed to create derivatives of OpenStreetMap data - for
example by tracing features on the OSM tiles - and freely distribute
them. Such derived datasets, unless they are "insubstantial"
(https://wiki.osmfoundation.org/wiki/Licence/Community_Guidelines/Substantial_-_Guideline)
inherit the ODbL license and must, when publicly used, on request be
made available under ODbL.

4. If the load coming from QGIS should be unexpectedly high and impact
our service performance, there might come a time where we'd have to
throttle or even switch off this access. You should have some mechanism
or plan that deals with that to avoid frustration among your user base -
maybe a mechanism where QGIS installations request updated tile sources
from a central service so you could notify them of the OSM tiles not
being available (or being available elsewhere) should the need arise.

-- 
Paolo Cavallini - www.faunalia.eu
QGIS & PostGIS courses: http://www.faunalia.eu/training.html
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