populating batch processing dialog
This option adds news rows using the values from an expression
which returns an array. (As opposed to "Calculate by Expression",
which works only on existing rows).
The intended use case is to allow populating the batch dialog
using complex numeric series, e.g. those created by the "generate_series"
expression function.
For example, adding rows for a batch buffer using the expression
generate_series(100, 1000, 50)
(results in new rows with values 100, 150, 200, .... 1000)
This new option is available under the Autofill menu for a column. Selecting it allows users
to create a new QGIS expression to use to update the value inside that column. Existing
parameter values (including those from other columns) are available for use inside
the expression via @variables.
E.g. this allows setting output file names to complex expressions like
'/home/me/stuff/buffer_' || left(@input, 30) || '_' || @distance || '.shp'
to an explicit widget in the table
The double-click-header action is very hidden, and many users will
not stumble upon this. By moving it to an explicit "Autofill" widget at the
top of the table, we make this important action much more user
discoverable.
It also gives the possibility of other, parameter specific, autofill
actions (e.g. fill by expression, fill by file pattern)
- for algorithms that produce directory output, it is possible to test
that directory contents are exactly the same (recursively)
- added possibility to have a project file loaded before an algorithm is run
- documented the new additions (+ few existing ones)
K-nearest neighbour joins from the Processing toolbox!
This algorithm takes an input vector layer and creates a new
vector layer that is an with additional attributes in its attribute table
The additional attributes and their values are taken from a second
vector layer, where features are joined by finding the closest features
from each layer.
By default only the single nearest feature is joined, but optionally
the join can use the n-nearest neighboring features instead.
If a maximum distance is specified, then only features which are
closer than this distance will be matched.
Instead of encouraging use of the internal Processing modules
(e.g. from processing.tools.general import run , import processing, ...)
instead expose all Python specific STABLE processing additions
to the qgis.processing module.
Instead, scripts and plugins should now use
from qgis.processing import run, algorithmHelp,...
This makes a clear distinction between internal Processing python
modules (i.e., everything else!) and the parts of Processing
which are stable and designed to be used by plugins and scripts.
TODO: QGIS 4.0 -- move the internal Processing plugin modules
to __processing, to clearer indicate that this is all internal
stuff.
