/ 
Clay-UI-0.06
/ Clay::UI::Role::Core::Stateful

NAME

Clay::UI::Role::Core::Stateful - require an explicit id on a Clay::UI widget

SYNOPSIS

use v5.22;
use Object::Pad;
use Clay::UI::Role::Core::Stateful;

class My::Tracked :strict(params) :does(Clay::UI::Role::Core::Stateful) {}

my $panel = My::Tracked->new(id => 'main-panel');    # ok
eval { My::Tracked->new } or warn $@;               # dies: no id

DESCRIPTION

Clay::UI::Role::Core::Stateful extends Clay::UI::Role::Core::Element and makes the id constructor parameter mandatory. Compose it for widgets whose Clay element needs the same id in every frame because Clay keeps state for it between frames. Clay::UI::Role::Layout::HasScroll composes it: Clay stores a scroll container's scroll position under its element id. Without an id a widget gets an id derived from its position (see "resolve_id" in Clay::UI::Role::Core::Element), which changes when the widget moves.

Hover, press and focus do not need an id: Clay::UI::Interaction tracks widgets by reference.

The role adds no methods. The constructor dies with Clay::UI::Role::Core::Stateful: widget 'My::Tracked' requires an explicit 'id' when id is missing or undef.

SEE ALSO

"id" in Clay::UI::Role::Core::Element, Clay::UI::Role::Layout::HasScroll.