How do you use the Contentful Middleman preview API in different build environment?

Question

Here's what I'm trying to achieve in principle, which obviously doesn't work since the contentful data needs to be retrieved before the build:

# Build command
bundle exec middleman contentful && bundle exec middleman build -e <ENV>

# config.rb

configure :prod do
  set :build_dir, 'build/prod'
  set :ENV, 'prod'

  activate :contentful do |f|
    f.space         = { hs: 'SPACE' }
    f.access_token  = 'TOKEN'
    f.cda_query     = { include: 2 }
    f.all_entries   = true
    f.content_types = { #... }
  end
end

configure :testSite do
  set :build_dir, 'build/test-site'
  set :ENV, 'test'

  activate :contentful do |f|
    use_preview_api = true
    #...
  end
end

Answer 1

You can use environment variables to switch on that.

# Build command
CONTENTFUL_ENV=<env> bundle exec middleman contentful && bundle exec middleman build -e <env>


# config.rb
access_token = nil
use_preview = false
case ENV['CONTENTFUL_ENV']
when 'prod'
  access_token = ENV['CONTENTFUL_PROD_TOKEN']
when 'testSite'
  access_token = ENV['CONTENTFUL_TEST_TOKEN']
  use_preview = true
end

activate :contentful do |f|
  f.space = {space_alias: ENV['CONTENTFUL_SPACE']}
  f.use_preview_api = use_preview
  f.access_token = access_token
  # ...
end

This way you can have multiple environments working together