Class: Ohm::Model::Collection

Inherits:

Object

• Object
• Ohm::Model::Collection

show all

Includes:

Enumerable

Defined in:

lib/ohm.rb

Overview

Instance Attribute Summary (collapse)

• - (Object) key readonly

  An instance of Key.

• - (Object) model readonly

  A subclass of Ohm::Model.

Instance Method Summary (collapse)

• - (Object) add(model)

  Adds an instance of Ohm::Model to this collection.

• - (Object) clear

  Delete this collection.

• - (true, false) empty?

  Whether or not this collection is empty.

• - (Collection) initialize(key, model) constructor

  A new instance of Collection.

• - (Object) replace(models)

  Simultaneously clear and add all models.

• - (Object) sort(options = {})

  Sort this collection using the ID by default, or an attribute defined in the elements of this collection.

• - (Object) sort_by(att, options = {})

  Sort the model instances by the given attribute.

• - (Array) to_a

  Array representation of this collection.

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# File 'lib/ohm.rb', line 290

def initialize(key, model)
  @key = key
  @model = model.unwrap
end

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# File 'lib/ohm.rb', line 283

def key
  @key
end

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# File 'lib/ohm.rb', line 286

def model
  @model
end

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# File 'lib/ohm.rb', line 298

def add(model)
  self << model
end

class Post < Ohm::Model
  list :comments, Comment
end

class Comment < Ohm::Model
end

post = Post.create
post.comments << Comment.create

post.comments.size == 1
# => true

post.comments.clear
post.comments.size == 0
# => true

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# File 'lib/ohm.rb', line 392

def clear
  key.del
end

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# File 'lib/ohm.rb', line 430

def empty?
  !key.exists
end

class Post < Ohm::Model
  list :comments, Comment
end

class Comment < Ohm::Model
end

post = Post.create
post.comments << Comment.create(:id => 100)

post.comments.map(&:id) == ["100"]
# => true

comments = (101..103).to_a.map { |i| Comment.create(:id => i) }

post.comments.replace(comments)
post.comments.map(&:id) == ["101", "102", "103"]
# => true

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# File 'lib/ohm.rb', line 422

def replace(models)
  model.db.multi do
    clear
    models.each { |model| add(model) }
  end
end

class Post < Ohm::Model
  attribute :title
end

p1 = Post.create(:title => "Alpha")
p2 = Post.create(:title => "Beta")
p3 = Post.create(:title => "Gamma")

[p1, p2, p3] == Post.all.sort.to_a
# => true

[p3, p2, p1] == Post.all.sort(:order => "DESC").to_a
# => true

[p1, p2, p3] == Post.all.sort(:by => "Post:*->title",
                              :order => "ASC ALPHA").to_a
# => true

[p3, p2, p1] == Post.all.sort(:by => "Post:*->title",
                              :order => "DESC ALPHA").to_a
# => true

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# File 'lib/ohm.rb', line 335

def sort(options = {})
  return [] unless key.exists

  opts = options.dup
  opts[:start] ||= 0
  opts[:limit] = [opts[:start], opts[:limit]] if opts[:limit]

  key.sort(opts).map(&model)
end

User.create :name => "B"
User.create :name => "A"

user = User.all.sort_by(:name, :order => "ALPHA").first
user.name == "A"
# => true

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# File 'lib/ohm.rb', line 357

def sort_by(att, options = {})
  return [] unless key.exists

  opts = options.dup
  opts.merge!(:by => model.key["*->#{att}"])

  if opts[:get]
    key.sort(opts.merge(:get => model.key["*->#{opts[:get]}"]))
  else
    sort(opts)
  end
end

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# File 'lib/ohm.rb', line 435

def to_a
  all
end