Class: Shamu::Entities::StaticRepository

Inherits:
Object
  • Object
show all
Defined in:
lib/shamu/entities/static_repository.rb

Overview

Implements an in-memory store of entities for static entities (rich enum types) offering standard read methods #find, #lookup and #list.

Instance Method Summary collapse

Constructor Details

#initialize(entities, missing_entity_class: nil) ⇒ StaticRepository

Returns a new instance of StaticRepository.

Raises:

  • (ArgumentError) 


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# File 'lib/shamu/entities/static_repository.rb', line 8

def initialize( entities, missing_entity_class: nil )
  raise ArgumentError, :entities if entities.map( &:id ).count != entities.map( &:id ).uniq.count

  entities = entities.dup.freeze unless entities.frozen?

  @entities             = entities
  @missing_entity_class = missing_entity_class || NullEntity.for( entities.first.class )
  @lookup_cache         = {}
end

Instance Method Details

#find(id = :not_set, &block) ⇒ Entity

Find an entity with the given id.

Returns:

  • (Entity) —

    the entity if found.

Raises:



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# File 'lib/shamu/entities/static_repository.rb', line 35

def find( id = :not_set, &block )
  raise ArgumentError, :id if id == :not_set && !block_given?

  value = block_given? ? yield : find_by( :id, id )
  value || not_found!
end

#find_by(attribute, value) ⇒ Entity

Find an entity with the given value on the named attribute.

Parameters:

  • value (Object) —

    to look for.

  • attribute (Symbol) —

    to interrogate.

Returns:

  • (Entity) —

    the entity if found.

Raises:



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# File 'lib/shamu/entities/static_repository.rb', line 24

def find_by( attribute, value )
  cache = attribute_cache( attribute )
  cache.fetch value do
    cache[ value ] = find_by_attribute( attribute, value )
  end
end

#list ⇒ List<Entity>

Returns all the entities in the repository.

Returns:

  • (List<Entity>) —

    all the entities in the repository.



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# File 'lib/shamu/entities/static_repository.rb', line 59

def list
  List.new entities
end

#lookup(*ids) ⇒ List<Entity>

Lookup all the entities in the repository with the given ids.

Parameters:

  • ids (Array<Integer>)

Returns:



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# File 'lib/shamu/entities/static_repository.rb', line 45

def lookup( *ids )
  cache = attribute_cache( :id )
  matching = ids.map do |id|
    entity = cache.fetch( id ) do
      entities.find { |e| e.id == id }
    end

    entity || missing_entity_class.new
  end

  List.new matching
end