Style standardisation

[bolismauro]

Changes:

• Added helpers for style standardisation
• Updated README with conventions
• Added bonmot helpers with related pod

Please check the readme carefully as it contains most of the work.

This PR doesn't provide any automation process from Sketch, but it creates a foundation for it. The idea is to start adopting this style and be ready for the automation step we will face in the (hopefully near) future

[cipolleschi]

Uhm... in general i like the approach but:

1. not all of us uses Sketch. In Delta, for instance, all our designs are only in InVision
2. the Style file will become very big, especially with big apps that have several views. We used a similar approach in Squat and ChatStories, but, at the end, the file was very cluttered and very hard to find what we were searching for.

Right now, in Yoga, we resolved to use a single file for the shared styles (e.g.: the navigation bar style) and, inside the UI folder, for each screen folder, we create a Screen+Style file in which we put the style of the Labels for that screen

[m4tbat]

One thing that's not clear to me is: why should we do this:

Tempura.applyStyle(Style.Layer.redView, to: self.backgroundView)

instead of simply doing this:

Style.Layer.redView(self.backgroundView)

?

[bolismauro]

RC

not all of us uses Sketch. In Delta, for instance, all our designs are only in InVision

well, I think it is suboptimal, but you can still do it. There is nothing that prevents you not use Sketc

the Style file will become very big, especially with big apps that have several views. We used a similar approach in Squat and ChatStories, but, at the end, the file was very cluttered and very hard to find what we were searching for.

You can create multiple extensions of Text, I don't think it is a problem (it will become when/if we will automate the process)

@madbat I prefer it too, but it is quite hard / impossible to implement. If you want to try let me know

[m4tbat]

@bolismauro 🤔 maybe I'm missing something.

This example function from the README

 extension Style.Layer {
   static func redView(_ view: UIView) {
     view.backgroundColor = .red
   }
 }

shouldn't it just be possible to use it like this inside my view's style method:

Style.Layer.redView(self.backgroundView)

?

[smaramba]

@madbat It is indeed possible, one reason not to do that is to have a Tempura function that is always invoked when styling, in case we want to do something later on...
My opinion is that Style.Layer.redView(self.backgroundView) is better for the time being, given that the other approach would introduce asymmetry in the styling of Text and Layers.
This means that all the code changes in this PR needs to be reverted and we only add the recommendations in the README.
@bolismauro

[smaramba]

• removed the Tempura.applyStyle function
• updated the README
• fixed TempuraHelpers tests