Class: Kiba::Extend::Transforms::Fraction::ToDecimal

Inherits:

Object

• Object
• Kiba::Extend::Transforms::Fraction::ToDecimal

Defined in:

lib/kiba/extend/transforms/fraction/to_decimal.rb

Overview

Converts fractions expressed like “1 1/4” to decimals like “1.25”

Examples:

Defaults and general behavior/value handling

# Used in pipeline as:
# transform Fraction::ToDecimal, fields: :dim
xform = Fraction::ToDecimal.new(fields: :dim)
input = [
  {dim: nil},
  {dim: ''},
  {dim: 'foo'},
  {dim: '1/2'},
  {dim: '6-1/4 x 9-1/4'},
  {dim: '10 5/8x13'},
  {dim: '1 2/3 x 5 1/2'},
  {dim: 'approximately 2/3 by 1/2in (height unknown)'}
]
result = input.map{ |row| xform.process(row) }
expected = [
  {dim: nil},
  {dim: ''},
  {dim: 'foo'},
  {dim: '0.5'},
  {dim: '6.25 x 9.25'},
  {dim: '10.625x13'},
  {dim: '1.6667 x 5.5'},
  {dim: 'approximately 0.6667 by 0.5in (height unknown)'}
]
expect(result).to eq(expected)

Multiple fields and targets

# Used in pipeline as:
# transform Fraction::ToDecimal, fields: %i[w h], targets: %i[width height]
xform = Fraction::ToDecimal.new(fields: %i[w h], targets: %i[width height])
input = [{w: '8 1/2', h: '11'}]
result = input.map{ |row| xform.process(row) }
expected = [{w: '8 1/2', h: '11', width: '8.5', height: '11'}]
expect(result).to eq(expected)

Multiple fields and targets, and delete_sources = true

# Used in pipeline as:
# transform Fraction::ToDecimal, fields: %i[w h], targets: %i[w height], delete_sources: true
xform = Fraction::ToDecimal.new(fields: %i[w h], targets: %i[w height], delete_sources: true)
input = [{w: '8 1/2', h: '11'}]
result = input.map{ |row| xform.process(row) }
expected = [{w: '8.5', height: '11'}]
expect(result).to eq(expected)

target_format: :float and places: 2

# Used in pipeline as:
# transform Fraction::ToDecimal, fields: :w, target_format: :float, places: 2
xform = Fraction::ToDecimal.new(fields: :w, target_format: :float, places: 2)
input = [
  {w: '8-2/3'},
  {w: '2/3 in'}
]
result = input.map{ |row| xform.process(row) }
expected = [
  {w: 8.67},
  {w: '0.67 in'}
]
expect(result).to eq(expected)

target_format: :float, places: 2, whole_fraction_sep: [' ']

# Used in pipeline as:
# transform Fraction::ToDecimal,
#   fields: :w,
#   target_format: :float,
#   places: 2,
#   whole_fraction_sep: [' ']
xform = Fraction::ToDecimal.new(
  fields: :w, target_format: :float, places: 2, whole_fraction_sep: [' ']
)
input = [
  {w: '8-2/3'},
  {w: '2/3 in'}
]
result = input.map{ |row| xform.process(row) }
expected = [
  {w: '8-0.67'},
  {w: '0.67 in'}
]
expect(result).to eq(expected)

Instance Method Summary

• #initialize(fields:, targets: nil, target_format: :string, places: 4, whole_fraction_sep: [" ", "-"], delete_sources: false) ⇒ ToDecimal constructor

  A new instance of ToDecimal.

• #process(row) ⇒ Object

Constructor Details

#initialize(fields:, targets: nil, target_format: :string, places: 4, whole_fraction_sep: [" ", "-"], delete_sources: false) ⇒ ToDecimal

Returns a new instance of ToDecimal.

Parameters:

• fields (Symbol, Array(Symbol)) —

  Source data fields. If no targets given, converted values are written back into the original fields.

• targets (nil, Symbol, Array(Symbol)) (defaults to: nil) —

  Target data fields, if different from source data fields. If targets are specified at all, a target must be specified for each value in fields. The target for a given field can be the same as the given field, however.

• target_format (:string, :float) (defaults to: :string) —

  If fractions are being extracted from longer text strings and replaced, this should always be :string. Likewise if there may be more than one fraction in a given field value. This is the usual expected case. If the source data fields are known to only contain single fraction values and you need to use them in calculations in subsequent transforms within the same job, you may wish to set this as :float for greater accuracy.

• places (Integer) (defaults to: 4) —

  Number of decimal places. Applied if target_format = :string

• whole_fraction_sep (Array(String)) (defaults to: [" ", "-"]) —

  List of characters that precede a fraction after a whole number, indicating that the whole number and fraction should be extracted together. See Utils::ExtractFractions for further explanation.

• delete_sources (Boolean) (defaults to: false) —

  If targets are given, fields are deleted from row. Has no effect if no targets are given, or if the target for a field equals the field.

# File 'lib/kiba/extend/transforms/fraction/to_decimal.rb', line 107

def initialize(fields:,
  targets: nil,
  target_format: :string,
  places: 4,
  whole_fraction_sep: [" ", "-"],
  delete_sources: false)
  @fields = [fields].flatten
  @targets = targets ? [targets].flatten : nil
  @target_format = target_format
  @places = places
  @delete_sources = delete_sources
  @extractor = Kiba::Extend::Utils::ExtractFractions.new(whole_fraction_sep: whole_fraction_sep)
end

Instance Method Details

#process(row) ⇒ Object

Parameters:

• row (Hash{ Symbol => String, nil })

# File 'lib/kiba/extend/transforms/fraction/to_decimal.rb', line 122

def process(row)
  fields.each { |field| to_decimal(field, row) }
  delete_source_fields(row)
  row
end