til/rails/parameterize-a-string-with-underscores.md

Parameterize A String With Underscores

I have human-readable status strings that I'm working with like In progress, Pending approval, and Completed. I need to deterministically turn those into parameterized values that I can compare. That is, I want them lowercased and separated by underscores instead of spaces.

The ActiveSupport #parameterize method, as is, gets me pretty close.

> statuses = [
  "In progress",
  "Pending approval",
  "Completed"
]

> statuses.map(&:parameterize)
=> [
  "in-progress",
  "pending-approval",
  "completed"
]

Those are separated by dashes though. Fortunately, parameterize takes a separator option that we can use to verride what character is used to separate words. Let's use an underscore (_).

> statuses.map { |str| str.parameterize(separator: '_') }
=> [
  "in_progress",
  "pending_approval",
  "completed"
]

See the #paramterize docs for more details.