Class: Perron::Relation

Inherits:
Array
  • Object
show all
Defined in:
lib/perron/relation.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(resources = [], model_class = nil) ⇒ Relation

Returns a new instance of Relation.



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# File 'lib/perron/relation.rb', line 5

def initialize(resources = [], model_class = nil)
  super(resources)

  @model_class = model_class
end

Instance Attribute Details

#model_class ⇒ Object (readonly)

Returns the value of attribute model_class.



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# File 'lib/perron/relation.rb', line 10

def model_class
  @model_class
end

Instance Method Details

#in_order_of(attribute, values, filter: true) ⇒ Object 



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# File 'lib/perron/relation.rb', line 54

def in_order_of(attribute, values, filter: true)
  return Relation.new([]) if values.empty?

  indexed = values.each_with_index.to_h

  resources = if filter
    select { indexed.key?(it.public_send(attribute)) }
      .sort_by { indexed[it.public_send(attribute)] }
  else
    sort_by { indexed[it.public_send(attribute)] || Float::INFINITY }
  end

  Relation.new(resources)
end

#limit(count) ⇒ Object 



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# File 'lib/perron/relation.rb', line 28

def limit(count) = Relation.new(first(count), @model_class)

#offset(count) ⇒ Object 



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# File 'lib/perron/relation.rb', line 30

def offset(count) = Relation.new(drop(count), @model_class)

#order(attribute, direction = :asc) ⇒ Object 



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# File 'lib/perron/relation.rb', line 32

def order(attribute, direction = :asc)
  if attribute.is_a?(Hash)
    attribute, direction = attribute.first
  end

  sorted = sort_by { it.public_send(attribute) }

  Relation.new((direction == :desc) ? sorted.reverse : sorted, @model_class)
end

#pluck(*attributes) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/perron/relation.rb', line 42

def pluck(*attributes)
  raise ArgumentError, "wrong number of arguments (given 0, expected 1+)" if attributes.empty?

  map do |resource|
    if attributes.size == 1
      resource.public_send(attributes.first)
    else
      attributes.map { resource.public_send(it) }
    end
  end
end

#where(**conditions) ⇒ Object 



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# File 'lib/perron/relation.rb', line 12

def where(**conditions)
  filtered = select do |resource|
    conditions.all? do |key, value|
      key_value = resource.public_send(key)

      if value.is_a?(Array)
        value.map(&:to_s).include?(key_value.to_s)
      else
        key_value.to_s == value.to_s
      end
    end
  end

  Relation.new(filtered, @model_class)
end