Class: CalculableAttrs::Calculator

Inherits:
Object
  • Object
show all
Defined in:
lib/calculable_attrs/calculator.rb

Constant Summary collapse

CALCULABLE_FOREIGN_KEY = 
'__calculable_id__'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(relation: nil, foreign_key: nil, attributes: nil) ⇒ Calculator

Returns a new instance of Calculator.



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# File 'lib/calculable_attrs/calculator.rb', line 5

def initialize(relation: nil, foreign_key: nil, attributes: nil)
  @relation = relation
  @foreign_key = foreign_key

  @attrs = []
  @formulas = {}
  @defaults = {}

  attributes.each do |key, val|
    key = key.to_sym
    save_attribute_value(key, val)
    @attrs << key
  end
end

Instance Attribute Details

#attrs ⇒ Object (readonly)

Returns the value of attribute attrs.



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# File 'lib/calculable_attrs/calculator.rb', line 3

def attrs
  @attrs
end

#defaults ⇒ Object (readonly)

Returns the value of attribute defaults.



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# File 'lib/calculable_attrs/calculator.rb', line 3

def defaults
  @defaults
end

#foreign_key ⇒ Object (readonly)

Returns the value of attribute foreign_key.



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# File 'lib/calculable_attrs/calculator.rb', line 3

def foreign_key
  @foreign_key
end

#relation ⇒ Object (readonly)

Returns the value of attribute relation.



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# File 'lib/calculable_attrs/calculator.rb', line 3

def relation
  @relation
end

Instance Method Details

#base_query(attrs, id) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 51

def base_query(attrs, id)
  scoped_relation(id).select(build_select(attrs))
end

#calculable_foreign_key ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 28

def calculable_foreign_key
  CALCULABLE_FOREIGN_KEY
end

#calculate(attrs, id) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 20

def calculate(attrs, id)
  if id.is_a?(Array)
    calculate_many(attrs, id)
  else
    calculate_one(attrs, id)
  end
end

#calculate_all(id) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 47

def calculate_all(id)
  calculate(attrs, id)
end

#calculate_many(attrs, ids) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 32

def calculate_many(attrs, ids)
  query = query_with_grouping(attrs, ids)
  records = query.load
  normalize_many_records_result(ids, attrs, records)
end

#calculate_one(attrs, id) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 42

def calculate_one(attrs, id)
  record = base_query(attrs, id).load.first
  normalize_one_record_result(attrs, record)
end

#default(attr) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 63

def default(attr)
  @defaults.key?(attr) ? @defaults[attr] : 0
end

#query_with_grouping(attrs, ids) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 38

def query_with_grouping(attrs, ids)
  base_query(attrs, ids).select("#{ @foreign_key } AS #{ calculable_foreign_key }").group(@foreign_key)
end

#scoped_relation(id) ⇒ Object 



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# File 'lib/calculable_attrs/calculator.rb', line 55

def scoped_relation(id)
  if id
    @relation.call.where( @foreign_key => id)
  else
    @relation.call
  end
end