Returns the serialisable declaration block a host needs to enact a plot's
declarative interactivity (selections, conditional encodings, filters, and
scale-domain binds), or NULL when the plot declares none. This is the
plot-level companion to the per-element metadata carried on the compiled scene;
vellumwidget::as_widget() reads it to wire gestures to reactions.
Arguments
- x
A PlotSpec or a plot composition.
Value
A named list (selections, conditions, filters, binds, and
source when inspect_source() is declared), or NULL if there is no
declared interactivity.