Class: Nhgis::BreakdownCombo

Inherits:
NhgisActiveRecord::Base
  • Object
show all
Defined in:
app/models/nhgis/breakdown_combo.rb

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.defaults ⇒ Object 



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# File 'app/models/nhgis/breakdown_combo.rb', line 15

def self.defaults
  sql ="      SELECT bc.*\n      FROM breakdown_combos bc\n      JOIN breakdown_values_x_breakdown_combos x ON x.breakdown_combo_id = bc.id\n      JOIN breakdown_values bv                   ON bv.id = x.breakdown_value_id\n      GROUP BY bc.id HAVING COUNT(bv.id) = SUM(is_default);\n  EOS\n  find_by_sql(sql)\nend\n"

.find_by_breakdown_values(breakdown_value_istads_ids) ⇒ Object 



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# File 'app/models/nhgis/breakdown_combo.rb', line 26

def self.find_by_breakdown_values(breakdown_value_istads_ids)
  # there is an assumption that breakdown_value_istads_ids will contain the istads ids belonging to...
  #    NO breakdown value set (when empty),
  #    one breakdown value set (when breakdown value istads ids begin with the SAME prefix e.g. "bs01"
  #    two breakdown value sets (when breakdown value istads ids begin with one prefix or another e.g. "bs01" or "bs02"
  # ASSUMPTION is that there is never a valid breakdown combo where

  #puts "*** In find_by_breakdown_values #{breakdown_value_istads_ids.inspect}"
  breakdown_value_sets = breakdown_value_istads_ids.map{|bv|
  bv.
  split(".").
  first}.flatten.uniq

  case breakdown_value_sets.size
    when 0
      return []
    when 1
      sql_values = BreakdownCombo.istads_ids_for_sql(breakdown_value_istads_ids) 
      sql = "SELECT DISTINCT * FROM breakdown_combos WHERE istads_id IN (#{sql_values})"
    when 2
      bs1 = breakdown_value_sets.first
      bs2 = breakdown_value_sets.last
      bvs1 = breakdown_value_istads_ids.select{|bv| bv.split(".").first == bs1}
      bvs2 = breakdown_value_istads_ids.select{|bv| bv.split(".").first == bs2}
      sql_values1 = BreakdownCombo.istads_ids_for_sql(bvs1)
      sql_values2 = BreakdownCombo.istads_ids_for_sql(bvs2)

      sql = "SELECT DISTINCT bc.* FROM breakdown_combos bc "
      sql << "JOIN breakdown_values_x_breakdown_combos x ON x.breakdown_combo_id = bc.id "
      sql << "JOIN breakdown_values bv ON bv.id = x.breakdown_value_id AND bv.istads_id LIKE '#{bs1}.%' "
      sql << "JOIN breakdown_values_x_breakdown_combos x2 ON x2.breakdown_combo_id = x.breakdown_combo_id "
      sql << "JOIN breakdown_values bv2 ON bv2.id = x2.breakdown_value_id AND bv2.istads_id LIKE '#{bs2}.%' "
      sql << "WHERE bv.istads_id IN (#{sql_values1}) AND bv2.istads_id IN (#{sql_values2})"
    else
      raise "too many breakdown value sets; only expected 1 or 2 (or none)"
  end
  find_by_sql(sql)
end

.istads_ids_for_sql(breakdown_value_istads_id_list) ⇒ Object 



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# File 'app/models/nhgis/breakdown_combo.rb', line 10

def self.istads_ids_for_sql(breakdown_value_istads_id_list)
  #this method will convert an array of breakdown value istads id into a string that can be used in a sql statement
  breakdown_value_istads_id_list.inspect.gsub("[", "").gsub("]", "").gsub("\"", "'")
end

Instance Method Details

#codebook_labels ⇒ Object 



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# File 'app/models/nhgis/breakdown_combo.rb', line 65

def codebook_labels
  sorted_breakdown_values.map{|bv| bv.composite_codebook_label}
end

#header_label ⇒ Object 



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# File 'app/models/nhgis/breakdown_combo.rb', line 69

def header_label
  #"[breakdown_var 1 value]: [breakdown_var 2 value]"
  # NOTE : currently sorting the breakdowns using the breakdown value set istads_id
  sorted_breakdown_values.map{|bv| bv.label}.join(": ")
end

#is_default? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'app/models/nhgis/breakdown_combo.rb', line 75

def is_default?
  breakdown_values.each{|bv| return false unless bv.is_default}
  return true
end

#sorted_breakdown_values ⇒ Object 



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# File 'app/models/nhgis/breakdown_combo.rb', line 80

def sorted_breakdown_values
  breakdown_values.sort{|a,b| a.breakdown_value_set.istads_seq <=> b.breakdown_value_set.istads_seq}
end