to use for their algorithm's parameters
Because some providers do not have support for all output types,
we need to give providers a way to restrict the default format
choices to those which are supported by the provider.
And add a new target CRS argument to parameterAsExtent. If set, and
the source CRS of the rectangle parameter can be determined, then
the returned value will be the rectangle automatically reprojected
to the desired target CRS.
And use it when we need to clone parameters (instead of more fragile
conversion to and from variants)
This fixes model loading which use algorithms which create python
subclasses of parameter definitions
This allows optional outputs (such as null geometry features detected
by the Remove Null Geometries algorithm) to be skipped by default
when desirable.
The previous naming was too easily confused with processing outputs.
Rename them to QgsProcessingParameterFileDestination, etc... to
make it clearer what they are used for.
QgsProcessingFeatureSink, not all QVariant types
Only strings/QgsPropertys are valid anyway, so instead of strings
use static properties. This makes it clearer what possible
values are permitted for the underlying source/sink definition.
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
input to a processing algorithm.
This allows parameter inputs to encapsulate extra information
relating to a feature source input, such as whether only
selected features from the source layer should be used.
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.
input to a processing algorithm.
This allows parameter inputs to encapsulate extra information
relating to a feature sink input, such as destination file
encoding and whether the sink layer should be loaded into
the project on completion
