This was a missing capability in the processing API - while algorithms
could declare multiple layer input parameters, there was no corresponding
multi-layer output. This meant that algorithms (such as Package Layers,
Vector Split) which create a set of layers which cannot be determined
in advance had no way to pass these generated layers on for further model
processing steps.
It's also useful for algorithms which operate on a specified folder,
processing all layers found there, and allowing these generated
outputs to be utilised in other model steps (e.g. packaging
all of them, merging them, etc)
fix#18053
correctly set enumeration widget in case the domain is not in public schema
also fixes an issue if two domain with the same are present in two schemas
These layers cause an error if you try to add them to QGIS.
TODO: change source select to use a nested tree and correctly
add group layers as a parent for child layers.
Since libspatialindex is not thread safe on all platforms, and
have expressed desire to remove the thread safety that they DO
have on remaining platforms, it's safer and easier for us
to manually add locks to QgsSpatialIndex and be gauranteed that
this class is thread safe on all platforms and libspatialindex
versions.
Also improve docs for the class.
Since the underlying libspatialindex is not thread safe
on some platforms (e.g. Windows), manual calls to detach()
must be made if a QgsSpatialIndex is to be accessed across
multiple threads.
Note that for platforms on which libspatialindex is thread
safe, calling detach() has no effect and does not force the
deep copy.
their unique id()
This is used when generating the QgsHelp url for algorithms
attached to the providers.
Implement helpId overrides for the native and 3d providers so
that they return 'qgis' helpIds, meaning that all QGIS processing
algorithm documentation can be kept within the same url path
regardless of which QGIS provider library it sits within.
This also allows us to freely move algorithms from the Python
'qgis' provider to c++ 'native' provider in future releases
without breaking the help URLs.
Fixes#17231
