Class: CustomSort::SortFields

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

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ SortFields

Returns a new instance of SortFields.



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# File 'lib/custom_sort.rb', line 30

def initialize

end

Class Method Details

.time_decay(table_name, time_column = "created_at") ⇒ Object 



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# File 'lib/custom_sort.rb', line 33

def self.time_decay table_name, time_column = "created_at"
  "EXTRACT(EPOCH FROM (NOW()::timestamp - #{table_name}.#{time_column}::timestamp))/(24*60*60)"
end

.time_decay_adjusted(table_name, lambda_key) ⇒ Object 



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# File 'lib/custom_sort.rb', line 37

def self.time_decay_adjusted table_name, lambda_key
  lambda_val = CustomSort::LAMBDA_VALUES[lambda_key]
  time_decay_query = CustomSort::SortFields.time_decay(table_name)
  lambda_val.nil? ? "1" : "exp(#{time_decay_query}*#{lambda_val})"
end