Include Hanami::Action::Response#exposures in view rendering context

[jodosha]

Syntax preview

class MyAction < Hanami::Action
  def handle(*, res)
    res[:users] = repo.all
    res[:foo] = "X"
    res.render(view, foo: "Y")
  end
end

The :users exposure is added to the view args for rendering.

In case of overlapping names between inline options passed to Hanami::Action::Response#render and Hanami::Action::Response#exposures, inline options will take the precedence.

In the example above the view will receive "Y" as value for :foo.

[timriley]

@jodosha nice addition! I've left a comment with a suggestion that I think should improve the clarity of handling clashing exposures/view render options.

If you agree on that, it'd be nice to get this in.

Longer term, I think we want to have a good think/discussion about the approach we recommend for application authors to follow re: passing objects to views and make sure that's well reflected in our future documentation. With both response exposures and view exposures existing, I can see things getting pretty confusing.

[cllns]

After merging #345, I realized this PR might provide the same functionality. It does it in a different place and higher up the call stack.

Which way is better @jodosha? Happy to use this one and revert #345. My understanding is that this PR would handle cases of people using hanami-controller with hanami-action without using ApplicationAction (which is what's used for hanami/hanami.) and #345 would not handle that case.

[jodosha]

@cllns @timriley Two things. ✌️ Please let me know if you agree.
@cllns In case of agreement, would you be able to expand this PR?

One: I would say it's better to push down to generic Action, even outside of hanami.

---

Two: We should consider the following usages:

Response exposures

We set an exposure in the response, which should be available to the corresponding view/template. This is what #345 is taking care of.

class MyAction < Hanami::Action
  def handle(*, res)
    res[:foo] = "bar"
  end
end

Rendering exposures

We explicitly set an exposure while invoking res.render. :foo must be available in the view/template. This is what this PR is taking care of. Dunno if this PR also covers #345 as well.

class MyAction < Hanami::Action
  def handle(*, res)
    res.render(view, foo: "bar")
  end
end

A mix of the previous use cases

Both :color and :foo must be available in the view/template. In case of conflict, the Hanami::Reponse#render wins.

class MyAction < Hanami::Action
  def handle(*, res)
    res[:color] = "red"
    res.render(view, foo: "bar")
  end
end

[timriley]

@jodosha I agree with both your suggestions, and would love to see this PR expanded to cover them! @cllns, let me know what you think and if you'd be happy to work on this 😄

[cllns]

@timriley @jodosha Yup, I can see this PR through

[cllns]

Rebased this branch, removed the change from #345 and all the tests still pass 🙌 . So this original change to Hanami::Action::Response#render does handle the actual sending the exposures to the view and we don't need to do it twice. Now it's at the appropriate spot, since it'll work for both StandaloneActions and ApplicationActions.

@jodosha @timriley please review

[jodosha]

@cllns LGTM 👍 I'm the original author of the PR, so I can't approve it 😉

[timriley]

This is great 👍🏼