Improve how --output works

[mdb]

Currently, many of the command functions have logic like this to determine the correct output. It might be good to re-imagine how this could work in a more elegant way that wouldn't require repetitive if checks in each function.

[SuddenGunter]

Is it up for grabs? May I take it?

[britneywright]

go for it @SuddenGunter 👍🏽

[SuddenGunter]

ok
I've started implementation 2 days ago here: https://github.com/SuddenGunter/vinyldns-cli
but was unable to continue since. Hope will have more time this weekend.

[SuddenGunter]

@britneywright @mdb I'm stuck, need your opinion how it would be better to approach this.
I've got 2 potential solutions at the moment:
1 extract "printing functions" with 'json' check. Something like this:
https://github.com/SuddenGunter/vinyldns-cli/commit/aa688f955e5ed2a764ef17b7de75175f21d26b6a
Pros:

• simple
  Cons:
• doesn't solve the issue, just hides it temporary - still would be code duplications, but a little less.

2 Use dependency injection. From my POV it would be the best approach here.
We would have some kind of a 'state' that knows how "printing subsystem" works. Basically, just a map of type->func(e element_of_type) error for each printable type we have.
When the app initializes it checks flags, and then builds that map with values. If "json" flag is present it would be simple - we have only 1 implementation for everything. If "json" flag is absent we fill map with print functions (we still would need to extract printing/formatting output logic from other code through).
Pros:

• no code duplication
• if tomorrow you want to add yml, xml, etc output - there are only 1 place to change + write all printing functions
• code looks better
  Cons:
• code is not so straight and simple to read

For 2nd approach we could use some DI package like Wire with it's codegen or dig, or do it manually - we need simple type->func mapping and one 'if' statement

[mdb]

@SuddenGunter It's a bit difficult to comment in too much depth without seeing your #2 "Dependency injection" idea in implementation. Would you feel comfortable creating an implementation we could review?

Alternatively, I defer to you to assess what you think is the best candidate and we can vet it together in code review.

Taking a step back, I do think my ideal solution balances simplicity, elegance, and future scenarios where it may be desirable to add additional output formats, such as CSV, XML, etc.

[SuddenGunter]

@mdb pls unassign this from me, would be able to fix it in close time
sorry