module DatabaseCachedAttribute

DatabaseCachedAttribute adds a method to add a set of easy to use cache invalidation methods/callbacks for specified attributes

On the model where you possibly may want to cache things from this model that may be heavy to create:

include DatabaseCachedAttribute
database_cached_attribute :attribute_name, :another_attribute_name

This will create the methods

invalidate_attribute_name(optional_object)
invalidate_another_attribute_name(optional_object)
cache_attribute_name(optional_object)
cache_another_attribute_name(optional_object)

Which means invalidating that attribute is easy, say when you add an associated object

has_many :things, before_add: :invalidate_attribute, before_remove: :invalidate_other_attribute

Constants

VERSION

Public Instance Methods

invalidate_cache(column_name) click to toggle source

Cache invalidation by column

# File lib/database_cached_attribute.rb, line 23
def invalidate_cache (column_name)
  self[column_name.to_sym] = nil
  update_cache column_name.to_sym
end

only_change?(column_name) click to toggle source

Determines if the provided column name is the only change

# File lib/database_cached_attribute.rb, line 34
def only_change? (column_name)
  changes.length == 1 && changes.has_key?(column_name)
end

only_changes?(*column_names) click to toggle source

Determines if the provided column names are the only changes

# File lib/database_cached_attribute.rb, line 39
def only_changes? (*column_names)
  return false if changes.length != column_names.length

  column_names.each do |column_name|
    return false if !changes.has_key?(column_name)
  end

  true
end

only_changes_in?(*column_names) click to toggle source

Determines if the changes, if any, are only in the list of column names provided

# File lib/database_cached_attribute.rb, line 50
def only_changes_in? (*column_names)
  return false if changes.length > column_names.length

  our_changes = changes.slice column_names
  return false if our_changes.length < changes.length

  true
end

update_cache(column_name) click to toggle source

Update cache by column

# File lib/database_cached_attribute.rb, line 29
def update_cache (column_name)
  save if only_change?(column_name) && persisted?
end