Contents

module BusinessFlow
  # Extends the DSL to support caching of completed processes
  module Cacheable
    def self.included(klass)
      klass.extend(ClassMethods)
    end

    def cache_key
      klass = self.class
      "#{klass.name}/#{klass.cache_key.call(self, nil)}"
    end

    # DSL Methods
    module ClassMethods
      def cache_store(store = nil)
        if store
          @cache_store = store
        else
          @cache_store ||= ActiveSupport::Cache::MemoryStore.new
        end
      end

      def cache_ttl(ttl = nil)
        if ttl
          @cache_ttl = ttl
        else
          @cache_ttl
        end
      end

      def cache_key(key = nil)
        if key
          @cache_key = Callable.new(key, self)
        else
          @cache_key ||= Callable.new(:parameter_object, self)
        end
      end

      def call(*args)
        flow = new(*args)
        PrivateHelpers.execute(self, flow)
      rescue FlowFailedException
        flow
      end
    end

    # Avoid polluting the namespace of whoever includes us
    module PrivateHelpers
      def self.execute(klass, flow)
        klass.cache_store.fetch(flow.cache_key, cache_options(klass)) do
          flow.call
          raise FlowFailedException, flow if flow.errors.any?
          flow
        end
      end

      def self.cache_options(klass)
        # compact is not available in Ruby <2.4 or ActiveSupport < 4, so
        # we can't use it here.
        options = {}
        ttl = klass.cache_ttl
        options[:expires_in] = ttl if ttl
        options
      end
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
business_flow-0.6.0	lib/business_flow/cacheable.rb
business_flow-0.5.2	lib/business_flow/cacheable.rb