pub fn substitute_attrs(
attrs: &Attributes,
slots: &[InterpolationSlot],
scope: &Scope<'_>,
) -> Option<Attributes>Expand description
The attributes to build an element with, once the placeholders in its own
strings are resolved against scope.
None when nothing changed: an element with no placeholder in it, or one
whose placeholders the scope has no value for. The caller then builds the
element from the attributes it already has, and nothing is copied.
Children belong to whoever is walking the tree. substitute_element
walks one subtree with a scope that does not change under it; a caller
that carries its own walk, such as the web emitter or the spawner, calls
this at each element it reaches.