Class: Kiba::Extend::Transforms::Report::Fields

Inherits:
Object
  • Object
show all
Defined in:
lib/kiba/extend/transforms/report/fields.rb

Overview

Combines a number of other transforms into a one-step way of outputting a report of specified fields. Optionally, rows not having any information in a specified set of fields will be omitted from the report.

Examples:

With defaults

# Used in pipeline as:
# transform Report::Fields, fields: %i[id foo baz]
xform = Report::Fields.new(fields: %i[id foo baz])

input = [
  {id: "1", foo: "a", bar: "b", baz: "f"},
  {id: "2", foo: "a", bar: "b", baz: "f"},
  {id: "3", foo: "c", bar: "d", baz: "g"},
  {id: "4", foo: "c", bar: nil, baz: nil},
  {id: "5", foo: nil, bar: "d", baz: "i"},
  {id: "6", foo: "", bar: "", baz: ""},
  {id: "7", foo: nil, bar: "d", baz: nil}
]
result = Kiba::StreamingRunner.transform_stream(input, xform)
  .map{ |row| row }
expected = [
  {id: "1", foo: "a", baz: "f"},
  {id: "2", foo: "a", baz: "f"},
  {id: "3", foo: "c", baz: "g"},
  {id: "4", foo: "c", baz: nil},
  {id: "5", foo: nil, baz: "i"},
  {id: "6", foo: "", baz: ""},
  {id: "7", foo: nil, baz: nil}
]
expect(result).to eq(expected)

Default filtering (any)

# Used in pipeline as:
# transform Report::Fields,
#   fields: %i[id foo baz],
#   filter_fields: %i[foo baz]
xform = Report::Fields.new(fields: %i[id foo baz],
  filter_fields: %i[foo baz])

input = [
  {id: "1", foo: "a", bar: "b", baz: "f"},
  {id: "2", foo: "a", bar: "b", baz: "f"},
  {id: "3", foo: "c", bar: "d", baz: "g"},
  {id: "4", foo: "c", bar: nil, baz: nil},
  {id: "5", foo: nil, bar: "d", baz: "i"},
  {id: "6", foo: "", bar: "", baz: ""},
  {id: "7", foo: nil, bar: "d", baz: nil}
]
result = Kiba::StreamingRunner.transform_stream(input, xform)
  .map{ |row| row }
expected = [
  {id: "1", foo: "a", baz: "f"},
  {id: "2", foo: "a", baz: "f"},
  {id: "3", foo: "c", baz: "g"},
  {id: "4", foo: "c", baz: nil},
  {id: "5", foo: nil, baz: "i"},
]
expect(result).to eq(expected)

Strict filtering (all)

# Used in pipeline as:
# transform Report::Fields,
#   fields: %i[id foo baz],
#   filter_fields: %i[foo baz],
#   filter_mode: :all
xform = Report::Fields.new(fields: %i[id foo baz],
  filter_fields: %i[foo baz], filter_mode: :all)

input = [
  {id: "1", foo: "a", bar: "b", baz: "f"},
  {id: "2", foo: "a", bar: "b", baz: "f"},
  {id: "3", foo: "c", bar: "d", baz: "g"},
  {id: "4", foo: "c", bar: nil, baz: nil},
  {id: "5", foo: nil, bar: "d", baz: "i"},
  {id: "6", foo: "", bar: "", baz: ""},
  {id: "7", foo: nil, bar: "d", baz: nil}
]
result = Kiba::StreamingRunner.transform_stream(input, xform)
  .map{ |row| row }
expected = [
  {id: "1", foo: "a", baz: "f"},
  {id: "2", foo: "a", baz: "f"},
  {id: "3", foo: "c", baz: "g"},
]
expect(result).to eq(expected)

Instance Method Summary collapse

Constructor Details

#initialize(fields:, filter_fields: nil, filter_mode: :any) ⇒ Fields

Returns a new instance of Fields.

Parameters:

  • fields (Symbol, Array<Symbol>) —

    names of fields to include in report

  • filter_fields (nil, Symbol, Array<Symbol>) (defaults to: nil) —

    names of fields to include in filter determining whether to keep rows based on whether fields are populated; When nil, no row filtering is done

  • filter_mode (:all, :any) (defaults to: :any) —

    how many of the filter fields must be populated in order to keep the row



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# File 'lib/kiba/extend/transforms/report/fields.rb', line 101

def initialize(fields:, filter_fields: nil, filter_mode: :any)
  @deleter = Delete::FieldsExcept.new(fields: fields)
  return unless filter_fields

  filter_xform = case filter_mode
  when :all then FilterRows::AllFieldsPopulated
  when :any then FilterRows::AnyFieldsPopulated
  end
  @filter = filter_xform.new(action: :keep, fields: filter_fields)
end

Instance Method Details

#process(row) ⇒ Object

Parameters:

  • row (Hash{ Symbol => String, nil }) 


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# File 'lib/kiba/extend/transforms/report/fields.rb', line 113

def process(row)
  deleter.process(row)
  return row unless instance_variable_defined?(:@filter)

  filter.process(row)
end