to a destination
Before we silently ignored these - now algorithms will automatically
push errors to the log if a feature cannot be written to a sink (no
changes to algorithms or special handling required)
Since netcdf, and possibly other gdal drivers, use layer uris
of the format NETCDF:"/tmp/test.nc":var1 we can't safely
remove or reformat these quotations.
This forces Python code and plugins to become datum transform
aware, and given that upgrading python code is easy (just
add QgsProject.instance() as a new argument to the constructor)
it's relatively painless to force this on PyQGIS users.
Also fix upgrade the easy QgsCoordinateTransform c++ constructors
where the project is available, or where using QgsProject::instance()
is safe to do.
For others, just avoid the deprecated warnings until we can
get access to the correct project instance where the transform
is being constructed.
...by moving extra arguments to new LayerOptions structs. This allows
us to more easily add new layer constructor options without making
the API cumbersome to use.
...even when invalid geometries are present and option is set to
skip invalid or break on invalid.
Some algorithms (e.g. those which repair geometries) need a way
to retrieve all features with invalid geometries, regardless of
the user's settings.
flexible QVariantMap creatOptions parameters which include an
optional fileEncoding value
More flexible, allows sinks to be created using any creation
option which is passed to the underlying provider
Instead, parameters evaluate to QgsFeatureSource, which are
used for retrieving features, feature count, crs, wkb type,
etc.
This abstracts away the actual feature source, so that
algorithms may potentially operate from non-layer
feature sources.
It also helps remove the need for specialised QgsProcessingUtils
methods like getFeatures, featureCount, and createSpatialIndex.
Instead the standard API methods using QgsFeatureSources can
be used instead.
Since the majority of users of this class will be exporting
an existing map layer to a data provider, the QgsVectorLayerImport
name is misleading and suggests that this class is designed
just to bring layers "into" QGIS.
Explicitly naming the class "Exporter" should help API users
discover this class.
Also cleanup API and improve docs
This implements an improved version of vector.createVectorWriter
in QgsProcessingUtils. The improved version relies on the
core class QgsVectorLayerImport to create empty layers,
which:
- reduces duplicate code and reuses the mature QgsVectorLayerImport
routines
- avoids manual conversion of field types to destination provider
field types
- potentially allows any writable provider to be used as a feature
sink for algorithms (e.g. output direct to MSSQL/Oracle/db2). This
should work now - it just needs exposing via UI.
