Hammer CLI

I'm going to sum up design discussion about this feature. tstrachota, ofedoren feel free to update/comment.

Commands will get a new option '--fields' (--columns could be confusing for base output adapter used in info commands):

subnet list --fields name,vlanid

Feature 'field set' will add predefined sets of fields

• default field sets available for all commands are going to be THIN and ALL.
• THIN is just 'id, name' and should use '?thin=true' in API for max optimization
• fields and field sets can be added from plugins
• name is ALLCAPS to distinguish between field name and set

subnet list --fields THIN

Things to figure out:

• position of the option in the Main or end command?
  - in main command it does not work with shell
  - in individual commands it could conflict with options coming from API
• can plugins remove fields from field sets?
• allow combination of a field set and field names (host list --fields DEFAULT,my-filed)?
• how to define the default filed set?
  - by field attribute :default => true/false (opt out) - hard to remove core filed from default set from plugin but works out of the box
  - by explicitly defining the DEFAULT field set - it would bring better control for plugins but we have to define the set before adding non-default fields

position of the option in the Main or end command?

IMO it makes more sense to define it on the terminal command. I'd say that the chance for a name clash is minimal.

can plugins remove fields from field sets?

What would be the use-case for that?

allow combination of a field set and field names (host list --fields DEFAULT,my-filed)?

Definitely, it adds a lot of flexibilitty.

I'll add two things:

• The option must be able to consume field labels that are presented to users, not keys that are used for looking up the data in API responses. E.g. --fields="Puppet environment" vs. --fields=environment
• It should be possible to select nested fields like IPs of a NIC. E.g. --fields="Network interfaces/IP"