* 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.
Uses new gradient editor widget and color controls for easier
manipulation of gradients. Also adds an interactive plot
for modifying gradient stops via the color HSV or RGB values.
Fix#8383
Sponsored by North Road
Supports:
- drag to move color stops
- double clicking to add a new stop
- pressing delete will remove the selected stop
- pressing arrow keys will move the selected stop, shift+arrow= larger
move
- drag and drop a color onto the widget to add a new stop
Sponsored by North Road
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
