Form Value Relation
Form (Aware) Value Relation Widget: an enhanced Value Relation widget and a custom function to read all the form values and build dynamic filters for your drill-down forms.
This is a core-enhancement plugin that allow the implementation of complex
dynamic filters in QGIS attribute forms.
This plugin provides a "Form Value Relation" widget (very similar clone of
QgsValueRelationWidgetWrapper) that refreshes the related item values on
every change in the form values and that makes available the form values to the
context. The expression is re-evaluated every time the form changes if
the changed fields are part of the expression.
A custom expression function "CurrentFormValue()" allow to read the form
values from the expression context.
This widget can be used to implement drill-down forms, where the values available
in one field depend on the values of other fields.
This plugin has been funded at 50% by "ARPA Piemonte"