class InfoparkComponentCache::Guards::ValidFrom

@author Tomasz Przedmojski <tomasz.przedmojski@infopark.de>

This guard ensures that any object that becomes valid (through valid_from) will cause inconsistency

Public Instance Methods

cache_key() click to toggle source

@return [String] the cache key for storing {#current_min_valid_from}

# File lib/infopark_component_cache/guards/valid_from.rb, line 32
def cache_key
  component.cache_key("min_valid_from")
end
consistent?() click to toggle source
# File lib/infopark_component_cache/guards/valid_from.rb, line 9
def consistent?
  if min_valid_from_known?
    no_changes_since?
  else
    current_min_valid_from.nil?
  end
end
current_min_valid_from() click to toggle source

@return [Time] the timestamp of the most recent valid_from, or nil if none found

# File lib/infopark_component_cache/guards/valid_from.rb, line 37
def current_min_valid_from
  str_value = scoped_relation.where("valid_from > ?", Time.now.to_iso).minimum(:valid_from)
  return str_value if str_value.kind_of? Time

  RailsConnector::DateAttribute.parse(str_value) if str_value.present?
end
guard!() click to toggle source
# File lib/infopark_component_cache/guards/valid_from.rb, line 17
def guard!
  cache.write(cache_key, current_min_valid_from)
end
min_valid_from_known?() click to toggle source

@return true if a timestamp can be read from cache with {#cache_key}

# File lib/infopark_component_cache/guards/valid_from.rb, line 22
def min_valid_from_known?
  cache.exist?(cache_key) && cache.read(cache_key).kind_of?(Time)
end
no_changes_since?() click to toggle source

@return true if no obj has been changed since last {#guard!}

# File lib/infopark_component_cache/guards/valid_from.rb, line 27
def no_changes_since?
  current_min_valid_from == cache.read(cache_key) && current_min_valid_from > Time.now
end