Class: Kiba::Extend::Transforms::Delete::FieldValueConditional

Inherits:

Object

• Object
• Kiba::Extend::Transforms::Delete::FieldValueConditional

Includes:

BooleanLambdaParamable

Defined in:

lib/kiba/extend/transforms/delete/field_value_conditional.rb

Overview

Delete a field value if the arbitrary Lambda passed in evaluates to true

Examples:

Without delim

xform = Delete::FieldValueConditional.new(
  fields: %i[a b],
  lambda: ->(val, row) { row[:c] == val }
)

input = [
  {a: nil, b: "", c: "c"},
  {a: "c", b: "b", c: "c"},
  {a: "a|c", b: "c", c: "c"}
]
result = Kiba::StreamingRunner.transform_stream(input, xform)
  .map{ |row| row }
expected = [
  {a: nil, b: nil, c: "c"},
  {a: nil, b: "b", c: "c"},
  {a: "a|c", b: nil, c: "c"}
]
expect(result).to eq(expected)

With delim

xform = Delete::FieldValueConditional.new(
  fields: %i[a b],
  lambda: ->(val, row) { row[:c] == val },
  delim: "|"
)

input = [
  {a: nil, b: "", c: "c"},
  {a: "c", b: "b", c: "c"},
  {a: "a|c", b: "c", c: "c"}
]
result = Kiba::StreamingRunner.transform_stream(input, xform)
  .map{ |row| row }
expected = [
  {a: nil, b: nil, c: "c"},
  {a: nil, b: "b", c: "c"},
  {a: "a", b: nil, c: "c"}
]
expect(result).to eq(expected)

Instance Method Summary

• #initialize(fields:, lambda:, delim: nil) ⇒ FieldValueConditional constructor

  A new instance of FieldValueConditional.

• #process(row) ⇒ Object

Methods included from BooleanLambdaParamable

included, #lambda_tested, #test_lambda

Constructor Details

#initialize(fields:, lambda:, delim: nil) ⇒ FieldValueConditional

Returns a new instance of FieldValueConditional.

Parameters:

• fields (Array<Symbol>, Symbol) —

  field(s) to delete from

• lambda (Lambda) —

  with one parameter for row to be passed in through. The Lambda must take val and row positional arguments and evaulate to/return TrueClass or FalseClass

• delim (nil, String) (defaults to: nil) —

  if provided, turns on multivalue mode; each whole field value is split into values, each of which is sent as val to the lambda

# File 'lib/kiba/extend/transforms/delete/field_value_conditional.rb', line 61

def initialize(fields:, lambda:, delim: nil)
  @fields = [fields].flatten
  @lambda = lambda
  @multival = delim ? true : false
  @delim = delim || Kiba::Extend.delim
end

Instance Method Details

#process(row) ⇒ Object

Parameters:

• row (Hash{ Symbol => String, nil })

Raises:

• (Kiba::Extend::BooleanReturningLambdaError) —

  if given lambda does not evaluate to TrueClass or FalseClass using the first row of data passed to the process method

# File 'lib/kiba/extend/transforms/delete/field_value_conditional.rb', line 72

def process(row)
  test_lambda(["foo", row]) unless lambda_tested

  fields.each { |field| row[field] = delete_from_field(row, field) }
  row
end