Add custom look

[goosys]

• resolves Multiple "looks" per Field #2291

---

Introduces a custom look implementation based on the discussion in #2291.

Changes:

• Added look option to FieldBase
  • Added RSpec tests for FieldBase
  • Updated RSpec tests for each Field
• Added look option to generators
  • Field generator
  • Custom Field generator
• Updated documentation
  • Custom Dashboard
  • Field generator
  • Custom Field generator
• Added example for changing BelongsTo look in demo app
  • product: Field::BelongsTo.with_options(look: :product_card)
  • The Product card now displays the product image and name side by side.

Please review and let me know if any changes are needed! 🚀

Usage:

class PageDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    product: Field::BelongsTo.with_options(look: :product_card)
  }
end
class LineItemDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    product: Field::BelongsTo.with_options(look: :product_card)
  }
end

/admin/pages

/admin/orders/:id

[goosys]

I added a sample since #2354 might also be easily resolved with looks. f280d50

/admin/products/:id/edit

[goosys]

@pablobm @nickcharlton

I've been playing around with this for the past few days, and it's incredibly fun! 🎉
I feel like this significantly expands the possibilities for customizing Administrate.
Some simple third-party custom field plugins could already be replaced with the looks feature.
Would you like to give it a try?

Also, could you update the beta tag to beta4 once looks is merged?
With virtual field, partial prefixes, and looks as the foundation, plugin development should become easier than before. Having an updated tag would be really helpful.

[nickcharlton]

Yay! Thanks for doing this.

I think it's a big enough conceptual change it should probably go in after v1, if not just so that we can highlight the new functionality and it not get lost in other changes. But I'm still thinking this through!

[goosys]

@nickcharlton

Thanks! That makes sense.

That said, since looks doesn’t break compatibility, I believe there’s no need to delay merging it. It’s stable as is, and if anything is missing, I’d be happy to help improve it further.

My application really depends on both looks and contextualize. Would it be possible to merge it now? 😭

[nickcharlton]

The code change is small, but it's a big (positive) step in functionality which makes a nice highlight for a next release. I'm just trying to see if I can draw a line and get v1 done, as I've dragged my feet on it much longer than I was hoping I'd do.

I appreciate this makes things annoying for you and your application though 😭

[goosys]

Thank you! I really appreciate it. I’m looking forward to the completion of v1. 😊

[pablobm]

Looking great! 🙂 Let some minor comments and after that I think this is a good first feature for the post-v1 release.

[pablobm]

@goosys - Do you want to rebase this, and we can see if we can give it another chance?

[goosys]

@pablobm
Rebased.
Some time has passed since then, so I may have forgotten if there were any remaining issues. Please let me know if you notice anything.

[pablobm]

I think this is good, just the minor comments. The one thing that I think is missing is simple tests to check that the example looks are working. I would write something like spec/example_app/spec/features/field_looks_spec.rb and examples checking some simple HTML: the <img> tags and the <optgroup> tag should do the trick.

Note that I would put these under spec/example_app/spec instead of under spec because they are things that I think users of Administrate should be testing when they customise their dashboards (it's their own code!), as opposed to things that Administrate should guarantee.

[goosys]

@pablobm
Thank you for the review. I've made the requested changes and pushed a new commit.

(The failing tests are due to a separate Ruby 4–related issue.)