Individual actions in the contextmenu of the attributetable and the relationeditorwidget.
It's unlink and delete feature in the relationeditorwidget.
It's delete feature in the attributetable (form view)
beside add and delete child in the relationwidget of an attributeform, there is the new functionality duplicate feature. this duplicates the selected child feature and (if the child has a relation with the strength composition too) the grad child features.
Also cleanup API for addFeature(s) in QgsVectorLayer, by removing
the unused extra argument from addFeature() and be removing the
makeSelected argument from addFeatures() (code should be adapted
to manually select added features after adding if desired - this
was only used in a single place in the QGIS code and I suspect
this was unintentional in any case)
In the attribute form, the collapsed state of RelationReference
was not loaded correctly and was interfering with the collapsed
state of the relation editor.
Plus, the state was saved globally for a reference. Meaning that
if a reference was used (through other references) from other
layers, it was sharing the same state.
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.
... because that the buttons are there was mainly triggered by the fact
that it's sometimes hard to find the appropriate layer in the legend.
Fix#15102
This adds the possibility to manage data on a normalized relational
database in N:M relations. On the relation editor in a form, the tools
to add, delete, link and unlink work (also) on the linking table if a
relation is visualized as N:M relation.
Configuration is done through the fields tab where on the relation a
second relation can be chosen (if there is a suitable relation in terms
of a second relation on the linking table).
Limitations
===========
QGIS is not a database management system.
It is based on assumptions about the underlying database system. In
particular it expects
* A `ON DELETE CASCADE` or similar measure on the second relation
* Does not take care of setting the primary key when adding features.
Either users need to be instructed to set them manually or - if it's a
database derived value - the layers need to be in transaction mode
(currently only activatable through the API)
Partially fixes#11266
* now passing editor context to QgsFeatureSelectionDlg
(otherwise fails on assert parentContext.vectorLayerTools())
* still crashes at the provider level after saving
* unlink still doesn't work
Rationale:
- there was a lot of large objects passed by value, so potentially
there's a speed bump from this
- even for implicitly shared classes like QString/QList there's still
a (small) cost for copying the objects when there's no reason to
- it's the right thing to do!
