[FEATURE] Add callback support

[Jonathan-Bailey-Bose]

Description

This PR utilizes the code from #757 written by @Makashov to add callback support to ReDoc. It further adds to the code by adding the following:

• Adds isCallback: boolean field to the OperationModel class in order to distinguish a normal Operation from a Callback. This defaults to false.
• Callbacks are defined with the following behavior as a type of Operation:
  • Callbacks by default will use the event name for the view's label when rendered by ReDoc, as opposed to the operationID.
  • Callbacks by default do not inherit the specification's global security definition(s). They default to having no security, and can have security added on an individual basis.
  • Callbacks by default do inherit the specification's global servers definition(s). In many cases, this can be undesirable. Override the servers property on individual callbacks to remedy this if needed.
• Adds some tests to maintain code coverage.
• The rendering style of a callback is meant to mimic that of an operation within an operation response dropdown.

[sundbry]

I gave this a shot and it worked flawlessly with our API spec. Thank you! It did add some extra debug logging to the output which I imagine should be removed before merging.

[Jonathan-Bailey-Bose]

@sundbry Glad to hear it! Thanks for the catch, forgot to remove that pesky line 😉

[RomanHotsiy]

Hey @Jonathan-Bailey-Bose! Thanks for your PR, we're super busy right now.

I hope I will be able to review and merge this PR early Feb

[bjokax]

Do we know if this can be merged soon!? We are using many resthooks/webhooks in our product and it would be nice to be able to document them properly with redoc!

[asyncee]

It would be great to have this feature in production.

[jchook]

Excited to see this merged as well. Looks great so far.

I did find a couple small bugs...

1. Servers

• components.callbacks.Test./test.post.servers does show in the UI
• components.callbacks.Test./test.servers does not show in the UI

2. Scrolling menu

Something about adding the callback section makes the menu disappear/jump to the top during scrolling. It appears to happen as you scroll into (or out of) a tag section that contains callbacks.

It also renders the menu inert.

For me, it only happens on Chromium 80 and not on FireFox 73.

[bjokax]

I think the Chrome 80 issue has been already fixed in the latest RC release!

[Zhendryk]

See #1167, I don't believe this branch has been rebased on top of that fix yet, but the fix exists in v2.0.0-rc.23

[Jonathan-Bailey-Bose]

Branch has been rebased ontop of latest changes, including the Chrome 80 fix.

[Jonathan-Bailey-Bose]

@RomanHotsiy Any idea of when this will be reviewed and merged?

[VersBinarii]

It would be really great to have this PR merged

[girishadat]

I hope the reviews for this PR is in progress. It would be great to have an RC build with this feature! @RomanHotsiy @Jonathan-Bailey-Bose

[RomanHotsiy]

Hey @Jonathan-Bailey-Bose!

Sorry for the huge delay. We're super busy. Thanks for your contribution again!

I found some time today to review the functionality of this PR 🎉

I have a few points:

1. There is a major issue with enpoint (see screenshot):
   

You use <Endpoint> component which is not adapted to callbacks. I believe that having URL in the middle panel would be more useful for callbacks, so I would put it next to the callback name, see screenshot for example:

2. Responses for callback is easy to confuse with general responses. Maybe we should wrap it into some background or maybe you have some better idea.

Are you willing to apply the changes? I can't ask you as you already put so much efforts into this and hit the huge delays from our side 😞. I can pick it up too.

Thanks

[RomanHotsiy]

Superseded by #1224