Class: ActiveMapper::Relation

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/active_mapper/relation.rb

Instance Method Summary collapse

Constructor Details

#initialize(mapped_class, adapter, &block) ⇒ Relation

Returns a new instance of Relation.



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# File 'lib/active_mapper/relation.rb', line 9

def initialize(mapped_class, adapter, &block)
  @mapped_class = mapped_class
  @adapter = adapter
  @block = block
end

Instance Method Details

#any? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_mapper/relation.rb', line 20

def any?
  count > 0
end

#avg(attribute) ⇒ Object Also known as: average 



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# File 'lib/active_mapper/relation.rb', line 53

def avg(attribute)
  @avg ||= @adapter.average(@mapped_class, attribute, &@block)
end

#count ⇒ Object Also known as: length, size 



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# File 'lib/active_mapper/relation.rb', line 33

def count
  @count ||= @adapter.count(@mapped_class, &@block)
end

#drop(number) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 62

def drop(number)
  @offset = number
  dup
end

#first(number = 1) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 88

def first(number = 1)
  objects = drop(0).take(number).to_a

  if number == 1
    objects.first
  else
    objects
  end
end

#initialize_copy(other) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 15

def initialize_copy(other)
  super
  @to_a = nil
end

#last(number = 1) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 98

def last(number = 1)
  objects = drop(0).take(number).reverse.to_a

  if number == 1
    objects.first
  else
    objects
  end
end

#max(attribute) ⇒ Object Also known as: maximum 



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# File 'lib/active_mapper/relation.rb', line 44

def max(attribute)
  @max ||= @adapter.maximum(@mapped_class, attribute, &@block)
end

#min(attribute) ⇒ Object Also known as: minimum 



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# File 'lib/active_mapper/relation.rb', line 39

def min(attribute)
  @min ||= @adapter.minimum(@mapped_class, attribute, &@block)
end

#minmax(attribute) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 49

def minmax(attribute)
  [min(attribute), max(attribute)]
end

#none? ⇒ Boolean Also known as: empty?

Returns:

  • (Boolean) 


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# File 'lib/active_mapper/relation.rb', line 24

def none?
  !any?
end

#one? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_mapper/relation.rb', line 29

def one?
  count == 1
end

#reject(&block) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 84

def reject(&block)
  select { |object| !block.call(object) }
end

#reverse ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 113

def reverse
  if @order
    block = @order.dup

    sort_by { |object| [block.call(object)].flatten.map(&:reverse) }
  else
    sort_by { |object| -object.id }
  end
end

#select(&block) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 72

def select(&block)
  if @block
    query = @block.dup
    
    @block = proc { |object| (query.call(object)) & block.call(object) }
  else
    @block = block
  end

  dup
end

#sort_by(&block) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 108

def sort_by(&block)
  @order = block
  dup
end

#sum(attribute) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 58

def sum(attribute)
  @sum ||= @adapter.sum(@mapped_class, attribute, &@block)
end

#take(number) ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 67

def take(number)
  @limit = number
  dup
end

#to_a ⇒ Object 



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# File 'lib/active_mapper/relation.rb', line 123

def to_a
  @to_a ||= @adapter.where(@mapped_class, options, &@block).map { |record| @adapter.unserialize(@mapped_class, record) }
end