Class: Burner::Library::Collection::Pivot

Inherits:
JobWithRegister show all
Defined in:
lib/burner/library/collection/pivot.rb

Overview

Take an array of objects and pivot a key into multiple keys. It essentially takes all the values for a key and creates N number of keys (one per value.) Under the hood it uses HashMath’s Record and Table classes: github.com/bluemarblepayroll/hash_math

An example of a normalized dataset that could be pivoted:

records = [

{ patient_id: 1, key: :first_name, value: 'bozo' },
{ patient_id: 1, key: :last_name,  value: 'clown' },
{ patient_id: 2, key: :first_name, value: 'frank' },
{ patient_id: 2, key: :last_name,  value: 'rizzo' },

]

Using the following job configuration:

config = 

unique_key: :patient_id

Once ran through this job, it would set the register to:

records = [

{ patient_id: 1, first_name: 'bozo', last_name: 'clown' },
{ patient_id: 2, first_name: 'frank', last_name: 'rizzo' },

]

Expected Payload input: array of objects. Payload output: An array of objects.

Constant Summary collapse

DEFAULT_PIVOT_KEY = 
:key
DEFAULT_PIVOT_VALUE_KEY = 
:value

Constants inherited from JobWithRegister

JobWithRegister::BLANK

Instance Attribute Summary collapse

Attributes inherited from JobWithRegister

#register

Attributes inherited from Job

#name

Instance Method Summary collapse

Methods included from Util::Arrayable

#array

Constructor Details

#initialize(unique_keys:, insensitive: false, name: '', other_keys: [], pivot_key: DEFAULT_PIVOT_KEY, pivot_value_key: DEFAULT_PIVOT_KEY_VALUE, register: DEFAULT_REGISTER, separator: '') ⇒ Pivot

Returns a new instance of Pivot.



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# File 'lib/burner/library/collection/pivot.rb', line 54

def initialize(
  unique_keys:,
  insensitive: false,
  name: '',
  other_keys: [],
  pivot_key: DEFAULT_PIVOT_KEY,
  pivot_value_key: DEFAULT_PIVOT_KEY_VALUE,
  register: DEFAULT_REGISTER,
  separator: ''
)
  super(name: name, register: register)

  @insensitive      = insensitive || false
  @pivot_key        = pivot_key.to_s
  @pivot_value_key  = pivot_value_key.to_s
  @resolver         = Objectable.resolver(separator: separator)
  @unique_keys      = Array(unique_keys)
  @other_keys       = Array(other_keys)
  @non_pivoted_keys = @unique_keys + @other_keys

  freeze
end

Instance Attribute Details

#insensitive ⇒ Object (readonly)

Returns the value of attribute insensitive.



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# File 'lib/burner/library/collection/pivot.rb', line 46

def insensitive
  @insensitive
end

#non_pivoted_keys ⇒ Object (readonly)

Returns the value of attribute non_pivoted_keys.



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# File 'lib/burner/library/collection/pivot.rb', line 46

def non_pivoted_keys
  @non_pivoted_keys
end

#other_keys ⇒ Object (readonly)

Returns the value of attribute other_keys.



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# File 'lib/burner/library/collection/pivot.rb', line 46

def other_keys
  @other_keys
end

#pivot_key ⇒ Object (readonly)

Returns the value of attribute pivot_key.



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# File 'lib/burner/library/collection/pivot.rb', line 46

def pivot_key
  @pivot_key
end

#pivot_value_key ⇒ Object (readonly)

Returns the value of attribute pivot_value_key.



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# File 'lib/burner/library/collection/pivot.rb', line 46

def pivot_value_key
  @pivot_value_key
end

#resolver ⇒ Object (readonly)

Returns the value of attribute resolver.



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# File 'lib/burner/library/collection/pivot.rb', line 46

def resolver
  @resolver
end

#unique_keys ⇒ Object (readonly)

Returns the value of attribute unique_keys.



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# File 'lib/burner/library/collection/pivot.rb', line 46

def unique_keys
  @unique_keys
end

Instance Method Details

#perform(output, payload) ⇒ Object 



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# File 'lib/burner/library/collection/pivot.rb', line 77

def perform(output, payload)
  objects = array(payload[register])
  table   = make_table(objects)

  output.detail("Pivoting #{objects.length} object(s)")
  output.detail("By key: #{pivot_key} and value: #{pivot_value_key}")

  objects.each { |object| object_to_table(object, table) }

  pivoted_objects = table.to_a.map(&:fields)

  output.detail("Resulting dataset has #{pivoted_objects.length} object(s)")

  payload[register] = pivoted_objects
end