Transforming yaml to another yaml.

data.yml

header:
  label: 'Header'
  breakpoint:
    fallback: 
      name: header_fallback
      label: 'Header @ fallback (306 x 172)'
      width: 306
      height: 172
    small: 
      name: header_small
      label: 'Header @ small (674 x 379)'
      width: 674
      height: 379  
    medium: 
      name: header_medium
      label: 'Header @ medium (674 x 379)'
      width: 674
      height: 379

trans.rb

#!/usr/bin/env ruby

require 'yaml'
require 'pp'
require 'erb'
require 'ostruct'

SHOW_YAML = true

def render_breakpoint(template, data = {})
  ERB.new(File.read(template)).result(OpenStruct.new(**data).instance_eval { binding })
end

def save_as_yaml(file_name, yaml)
  puts "Writing to #{file_name}"
  File.open(file_name, 'w') { |f| f.write yaml }
end

data = YAML.load_file('./data.yml')
data['header']['breakpoint'].each do |label, breakpoint|
  content = render_breakpoint('./trans_template.yml.erb', {
      header: data['header'],
      label: label,
      breakpoint: OpenStruct.new(breakpoint)
  })

  puts(content) if SHOW_YAML
  yaml = YAML.load(content)
  save_as_yaml("#{label}.yml", yaml.to_yaml)
end

trans_template.yml.erb

name: <%= breakpoint.name %>
label: <%= breakpoint.label %>
effects:
    id: image_scale_and_crop
    weight: 1
    data:
      width: <%= breakpoint.width %>
      height: <%= breakpoint.height %>