Support for negative conditional tokens

[bschrag620]

I really like the tokens and classes helpers. One thing I ran into is there are cases where under the true condition I need a token added, and under a false condition I need a different token added. Currently that might look something like this:

class View < ApplicationView
  def template
    div(class: tokens(true_case?: 'foo', false_case?: 'bar'))
  end

  def true_case?
  end

  def false_case?
    !true_case?
  end
end

The idea would be to utilize an array to hold the opposite value. I realize arrays are already a supported conditional token value so it would mean not supporting an array as a value for conditional tokens or allowing nested arrays to support the negative case:

class View < ApplicationView
  def template
    # idea here is when true_case? is false ['bar'] is selected
    div(class: tokens(true_case?: [['foo'], ['bar']]))
  end

  def true_case?
  end
end

I think there is an argument to be made about supporting a hash token where the return value from the conditional check is used as a lookup in the hash:

    div(class: tokens(value_method: {value_1: 'foo', value_2: 'bar', value_3: 'foobar'})

The refactor that lives in my head would involve creating a Phlex::TokenGenerator class, which token would instantiate.

[joeldrapper]

I really like this idea. Perhaps we could use a Hash instead? I’m thinking something like this.

div(
  class: tokens(
    active?: { then: "active", else: "inactive" }
  )
)

The Array is more concise and it matches the order of a ternary operator, but I think a Hash with then / else keys would pretty clear to read for people who are new to the framework, while the Array would definitely need to be learned.

The idea of using the method’s return value as a Hash look-up key is interesting, but I don't think it’s necessary as it's quite easy to implement yourself.

COLORS = {...}
SIZES = {...}
STYLES = {...}

div(
  class: tokens(COLORS[@color], STYLES[@style], SIZES[@size])
)

Or inline

div(
  class: tokens(
    {
      a: "foo",
      b: "bar"
    }[style]
  )
)

def style = :a

[bschrag620]

I can see the benefit to then/else as far as readability and ease of learning. Also a very valid point regarding implementing the hash lookup. I can play with this a bit this weekend and come up with something.

[bschrag620]

Submitted: #392