[Card section carousel] Discuss how to avoid adoptors setting too large number of cards per page

[asudoh]

The problem

While <dds-carousel> sets the default number of cards per page that best suits the available viewport width, <dds-carousel> also allows our adaptors to specify arbitrary number of cards per page, via page-size attribute. It caused weird UI caused by extreme page-size, as #4918 and #4919 reports.

The solution

This issue is to discuss how to prevent such misconfiguration. A couple of options I can rattle off are:

1. Define the maximum number of cards per page for different breakpoints, and ignore any page-size attribute value that exceeds that maximum number
2. Define several sets of number of cards per page (see below) and have adaptors use such set instead of having them directly set the page size

(Just example of 2., the actual numbers should be determined by design team)

Configuration	Number of cards per page for sm breakpoint	md	lg
SMALL	2	4	6
DEFAULT	1	2	3
LARGE	1	1	2

CC @jeffchew @kennylam @oliviaflory

[asudoh]

@RobertaJHahn We have short-term (band-aid) fix for #4918 and #4919 already (#4921) so that January release doesn't have to wait for the resolution of this issue, FYI.

[oliviaflory]

My thoughts:

The maximum number of cards or images sort of depends on how many columns of the grid the adopter is using. Adding some examples of my thinking here... I don't know if this is too complicated to achieve in storybook?

16 columns used on desktop view

Configuration	Number of Cards for sm breakpoint	Md	Lg–Max
Default	1	2	4
Large	1	1	2

12 columns used on desktop view

Configuration	Number of Cards for sm breakpoint	Md	Lg–Max
Default	1	2	3

8 columns used on desktop view

Configuration	Number of Cards for sm breakpoint	Md	Lg–Max
Default	1	1	2
Large	1	1	1

[asudoh]

Thanks @oliviaflory for your thoughts! Sounds that rather than preventing our adaptor from using too many cards per page, we want to provide good set of number (of cards per page) as (Storybook) examples. Is it correct?

[oliviaflory]

I think so @asudoh, and based on our explorations above, the maximum number or cards per page doesn't exceed 4 (in desktop) at this point.

[JennySanchez]

Per @oliviaflory
The PR following the proposed solution was merged into this last release.
https://app.zenhub.com/workspaces/carbon-for-ibmcom-5d449f3642eb1962336cbe52/issues/carbon-design-system/carbon-for-ibm-dotcom/4974

[JennySanchez]

FYI: @asudoh Adding this conversation to the "DDS Team Huddle 2021-03-02" for group discussion

[shixiedesign]

Discussed this issue during Team Huddle time today. The decisions are to simply remove knobs and remove any storybook entires that suggests the component will be used with different number of cards per page.