The basic idea is to split reading of XML definition and resolution of layer IDs into layers.
Also includes some cleanups in QgsProject and improvements in QgsVectorLayerJoinInfo.
Non-enforced constraints just show a warning to the user, but
do not prevent committing the feature. Enforced constraints
block users from comitting non compliant features.
Any constraints detected by the provider are always
enforced.
This allows to declare data dependencies between layers. A data
dependency occurs when a data modification in a layer, not by direct
user manipulation may modify data of other layers.
This is the case for instance when geometry of a layer is updated by a
database trigger after modification of another layer's geometry.
Allows an expression to be set for a vector layer field which
is used to evaluate a default value for this field.
A new method,
QgsVectorLayer::defaultValue( int index,
const QgsFeature& feature = QgsFeature(),
QgsExpressionContext* context = nullptr )
has been added which evaluates the default value for a given field
using the optionally passed feature and expression context. This
allows default values to utilise properties of the feature
which exist at the time of calling, such as digitized geometries.
The expression context parameter allows variables to be used
in default value expressions, making it easier to eg insert
a user's name, current datetime, project path, etc
Default values are set using QgsVectorLayer::setDefaultValueExpression()
and retrieved using defaultValueExpression()
* It's now implicitly shared, meaning that changes to the config
can be supervised and a signal is sent from QgsVectorLayer and
there is no risk of elements suddenly being deleted.
* Remove a bunch of methods that were in QgsVectorLayer for legacy
reasons.
Previously these methods would inconsistently handle the
edit buffer, eg uniqueValues would consider changed attributes
but not added features. Now uniqueValues, minimumValue and
maximumValue all consider both added features and changed
attribute values when performing their calculation.
The most noticable effect of this fix is that the unique
values widget now correctly shows values for features which
have been added but not yet committed to the provider.
* Save more data to QML
* Virtual fields
* Map tips
* Display expression
* Read only flag
* Streamline expression context generation
Whenever an object is able to generate an expression context it
implements the method createExpressionContext() declared in
QgsExpressionContextGenerator.
This makes a cleaner API and allows using QgsFieldExpressionWidget and
QgsDataDefinedButton from python because standard OO programming
approaches are used instead of callbacks and void pointers.
* Colorize output of doc and sip tests
* Fix build
* Fix sip complaints
* Fix rebase problems
* Workaround failing bindings test
