Improve usability of create game form

[garrettngarcia]

Fixes #11071

Before clicking "Create"

• Branch is derived from the latest master
• Add the pins or archive_alpha_games label if this change will break existing games
• Code passes linter with docker compose exec rack rubocop -a
• Tests pass cleanly with docker compose exec rack rake

Implementation Notes

Explanation of Change

Now selects number input field value on focus. Also added min and max player info to the form labels.

Tested on Safari and Chrome on iOS and Mac.

Screenshots

Any Assumptions / Hacks

[ollybh]

@garrettngarcia Thanks for looking into this highly annoying bug. However, I don't think that this is the correct way to fix this one.

The problem, as far as I understand it, is that we've got some over-zealous validation code. If you delete the player count from one of the boxes it sees the blank as zero, which is less than the minimum player could. So it helpfully re-populates the box with the minimum player count.

This needs to be redone so that the blank doesn't trigger adding the minimum player count. And we'd probably need to make sure that the form isn't submitted with an invalid player count – I think this validation code was added to prevent games being created with invalid counts.

[garrettngarcia]

@ollybh I see. I had it that way in an earlier version, but didn't want games to be created with invalid min and max so came up with the selection solution. I can change it back.

Where should this form validation be done? In JS or in the back end? Can you point me to some current validation logic to get me started?

[ollybh]

Where should this form validation be done? In JS or in the back end? Can you point me to some current validation logic to get me started?

Ideally both. There does appear to already be some front end validation:

18xx/assets/app/view/create_game.rb

Lines 418 to 421 in 4fa1406

	if game_params[:min_players].to_i < @min_p[title] || game_params[:max_players].to_i > @max_p[title]
	return store(:flash_opts,
	'Invalid playercount')
	end

I'm not sure how much back end validation there is. It might go in Lib::Engine::Game::Base.initialize. There is sort of a check for player count in check_optional_rules!…

18xx/lib/engine/game/base.rb

Lines 437 to 442 in 4fa1406

	def check_optional_rules!
	min_players = @players.size
	max_players = @players.size
	error_string = meta.check_options(@optional_rules, min_players, max_players)&.[](:error)
	raise OptionError, error_string if error_string
	end

…but the default implementation of meta.check_options does nothing:

18xx/lib/engine/game/meta.rb

Line 130 in 4fa1406

def check_options(_options, _min_players, _max_players); end