When attacking a battlefield and triggering a 'When I attack' ability, is there another chain during showdown before combat damage, or is there only one chain during combat?

Ruling: After the initial chain (when I attack, defend, actions/reactions) resolves, the attacker receives Focus and Priority and can play actions/reactions. There is no defined number of chains that can happen during a showdown.

Sequence:

• When I attack triggers go on the initial chain to start the showdown
• Initial chain resolves
• Attacker gets Focus and Priority
• Players can play actions/reactions until both pass
• This can create multiple chains before combat damage