teeparham/cache_replace

# frozen_string_literal: true

require "active_support/core_ext/string"
require "cache_rocket/key"
require "cache_rocket/fragment"
require "cache_rocket/version"

module CacheRocket
  include Key

  ERROR_MISSING_KEY_OR_BLOCK = "You must either pass a `replace` key or a block to render_cached."
  ERROR_MISSING_KEY = "You must pass a `replace` key to cache_replace."

  # Supports 5 options:
  #
  # 1. Single partial to replace.
  #    "inner" is the key name and "_inner.*" is the partial file name.
  #
  #   render_cached "container", replace: "inner"
  #
  # 2. Array of partials to replace
  #
  #   render_cached "container", replace: ["inner"]
  #
  # 3. Map of keys to replace with values
  #
  #   render_cached "container", replace: {key_name: a_helper_method(object)}
  #
  # 4. Yield to a hash of keys to replace with values
  #
  #   render_cached "container" do
  #     {key_name: a_helper_method(object)}
  #   end
  #
  # 5. Render a collection with Procs for replace values.
  #
  #   render_cached "partial", collection: objects, replace: { key_name: ->(object){a_method(object)} }
  #
  def render_cached(partial, options = {})
    replace_hash = options.delete(:replace)
    collection = options.delete(:collection)

    fragment = Fragment.new(render(partial, options))

    case replace_hash
    when Hash
      fragment.replace replace_hash, collection
    when NilClass
      raise(ArgumentError, ERROR_MISSING_KEY_OR_BLOCK) unless block_given?
      fragment.replace yield, collection
    else
      [*replace_hash].each do |key|
        fragment.gsub! cache_replace_key(key), render(key, options)
      end
    end

    fragment.to_s.html_safe
  end

  # This method works like Rails' CacheHelper#cache,
  # plus it replaces content in the replace hash.
  # It must have a `replace` option.
  #
  # - cache_replace(["key1", "key2"], replace: { name: "x" }) do
  #   .htmls
  #     = cache_replace_key :name
  #
  # https://github.com/rails/rails/blob/master/actionview/lib/action_view/helpers/cache_helper.rb
  def cache_replace(name = {}, options = {}, &block)
    replace_hash = options.delete(:replace)
    raise(ArgumentError, ERROR_MISSING_KEY) unless replace_hash

    name_options = options.slice(:skip_digest, :virtual_path)
    safe_concat \
      Fragment.new(
        fragment_for(cache_fragment_name(name, name_options), options, &block)
      ).replace(replace_hash).to_s.html_safe

    nil
  end
end