* Some formats require a compulsory encoding, typically UTF-8.
Change initMetadata() to indicate UTF-8 compulsory encoding for
GeoJSON, GeoRSS, GML, GPKG, GPX, KML, SQLite, SpatiaLite, FileGDB,
XLSX and ODS
* QgsVectorFileWriter::init(): make it override the user specified
encoding if the format has a compulsory encoding. And remove hard-coded
case for KML.
This commit adds a number of different forms of aggregates to
the expression engine.
1. Aggregates within the current layer, eg sum("passengers")
Supports sub expressions (ie sum("passengers"/2) ), group by
( sum("passengers", group_by:="line_segment") ), and optional
filters ( sum("passengers", filter:= "station_class" > 3 ) )
2. Relational aggregates, which calculate an aggregate over
all matching child features from a relation, eg
relation_aggregate( 'my_relation', 'mean', "some_child_field" )
3. A summary aggregate function, for calculating aggregates
on other layers. Eg aggregate('rail_station_layer','sum',"passengers")
The summary aggregate function supports an optional filter,
making it possible to calculate things like:
aggregate('rail_stations','sum',"passengers",
intersects(@atlas_geometry, $geometry ) )
for calculating the total number of passengers for the stations
inside the current atlas feature
In all cases the calculations are cached inside the expression
context, so they only need to be calculated once for each
set of expression evaluations.
Sponsored by Kanton of Zug, Switzerland
Can be used to store the results of expensive sub-expression
calculations (eg layer aggregates), so that future expression
evaluation using the same context does not have to recalculate
the cached values.
Move the QgsExpression::Interval class out to its own QgsInterval
class, extend with new methods and add tests
Add a typedef to keep API compatibility for 2.16
A "filled marker" is similar to the simple marker symbol layer, except
that it uses a fill sub symbol to render the marker. This allows use
of all the existing QGIS fill (and outline) styles for rendering
markers, eg gradient or shapeburst fills.
A new abstract class QgsSimpleMarkerSymbolLayerBase has been created
from which both QgsSimpleMarkerSymbolLayerV2 and
QgsFilledMarkerSymbolLayer derive. All common code has been moved to
this base class, allowing for easy addition of new shapes or features
to both simple markers and filled markers without duplication.
Also, adds a lot of missing docs to marker symbol layers.
- Closes https://hub.qgis.org/issues/14378
- Adds new virtual methods in QgsDataProvider(): enterUpdateMode() and leaveUpdateMode()
and implement them in the OGR provider. Limited to shapefiles and tabfiles
- Implements QgsOGRProvider:reloadData()
- Robustify OGR provider methods so they don't crash if dataset re-opening fails.
The original name was not representative for the scope of the class
and misleading at best.
The class manages actions for a given layer and it's not a single action
like the former name suggested.
There is a typedef introduced to keep it in the API until we can remove
it with QGIS 3.
