Class: Kiba::Extend::Transforms::Collapse::FieldsWithCustomFieldmap

Inherits:
Object
  • Object
show all
Includes:
SingleWarnable
Defined in:
lib/kiba/extend/transforms/collapse/fields_with_custom_fieldmap.rb

Overview

Combines values from multiple columns together as specified in fieldmap parameter.

If you are collapsing fields into target fields that are part of repeatable field groups, FieldsToRepeatableFieldGroup may be more appropriate.

Target field name can be the same as an existing field name.

Examples

Input table:

[
  {person: '', statusa: '', date: '',
   personb: '', statusb: '', date2: '',
   personc: '', statusc: '', date3: ''},
  {person: 'jim', statusa: 'approved', date: '2020',
   personb: 'bill', statusb: 'requested', date2: '2019',
   personc: 'terri', statusc: 'authorized', date3: '2018'},
  {person: 'jim|mavis', statusa: 'approved|', date: '2020|2021',
   personb: 'bill', statusb: 'requested', date2: '2019',
   personc: 'terri', statusc: 'authorized', date3: '2018'},
  {person: nil, statusa: 'acknowledged', date: '2020',
   personb: 'jill', statusb: 'requested', date2: nil,
   personc: 'bill', statusc: 'followup', date3: '2021'},
  {person: '%NULLVALUE%|%NULLVALUE%', statusa: 'acknowledged|approved', date: '2020|%NULLVALUE%',
   personb: 'jill', statusb: 'requested', date2: nil,
   personc: 'bill', statusc: 'followup', date3: '2019'}
]

Used in pipeline as:

 transform Collapse::FieldsWithCustomFieldmap,
   fieldmap: {
               :person => %i[person personb personc],
               :status => %i[statusc statusa statusb],
               :statusdate => %i[date date2 date3]
             }, delim: '|'

Results in:

[
  {person: '||',
   status: '|',
   statusdate: '',
   statusc: '', date2: '', date3: ''},
  {person: 'jim|bill|terri',
   status: 'approved|requested',
   statusdate: '2020',
  statusc: 'authorized', date2: '2019', date3: '2018'},
  {person: 'jim|mavis|bill|terri',
   status: 'approved||requested',
   statusdate: '2020|2021',
  statusc: 'authorized', date2: '2019', date3: '2018'},
  {person: '|jill|bill',
   status: 'acknowledged|requested',
   statusdate: '2020',
  statusc: 'followup', date2: nil, date3: '2021'},
  {person: '%NULLVALUE%|%NULLVALUE%|jill|bill',
   status: 'acknowledged|approved|requested',
   statusdate: '2020|%NULLVALUE%',
  statusc: 'followup', date2: nil, date3: '2019'}
]

NOTE

If it is important that the number of values in each target column match in each row, depending on the situation, you may need to employ %NULLVALUE% or other placeholder value to ensure this. For example, contrast row 3 and 4 of the example. Row 3 works because an empty column value gets treated as a single value. Thus, it sees 3 person, status, and statusdate values, even though one person and one date value are nil.

If the person column of row 4 were like this:

| person  | statusa               | date | personb | statusb   | date2 | personc | statusc    | date3 |
|---------|-----------------------|------|---------|-----------|-------|---------|------------|-------|
| nil     | acknowledged|approved | 2020 | jill    | requested | nil   | bill    | followup   |  2019 |

Then output would be:

| person     | status                                   | statusdate |
|--------------------------------------------------------------------|
| |jill|bill | followup|acknowledged|approved|requested | 2020||2019 |

Depending on your requirements, this could be problematic because you now have 3 values in person and statusdate, but 4 values in status

Otherwise, you can collapse fields in whatever way you like. For example, used in pipeline as:

 transform Collapse::FieldsWithCustomFieldmap,
   fieldmap: {
               :person => %i[person personb personc],
               :status => %i[statusa statusb],
               :statusdate => %i[date]
             }, delim: '|'

Results in:

[
  {person: '||',
   status: '|',
   statusdate: '',
   statusc: '', date2: '', date3: ''},
  {person: 'jim|bill|terri',
   status: 'approved|requested',
   statusdate: '2020',
  statusc: 'authorized', date2: '2019', date3: '2018'},
  {person: 'jim|mavis|bill|terri',
   status: 'approved||requested',
   statusdate: '2020|2021',
  statusc: 'authorized', date2: '2019', date3: '2018'},
  {person: '|jill|bill',
   status: 'acknowledged|requested',
   statusdate: '2020',
  statusc: 'followup', date2: nil, date3: '2021'},
  {person: '%NULLVALUE%|%NULLVALUE%|jill|bill',
   status: 'acknowledged|approved|requested',
   statusdate: '2020|%NULLVALUE%',
  statusc: 'followup', date2: nil, date3: '2019'}
]

More on fieldmap parameter

  • fieldmap is a Hash
  • Each key is a target field, given as a Symbol, into which values from multiple other fields will be combined
  • Each value is an Array of Symbols. Each element of the array is a source field that will be mapped into the target field given as key. Order of source fields in this array controls the order in which the source fields are combined.
  • There must be an equal number of source fields given in each source field Array

Since:

  • 2.9.0

Instance Method Summary collapse

Methods included from SingleWarnable

single_warnings

Constructor Details

#initialize(fieldmap:, delim:, delete_sources: true) ⇒ FieldsWithCustomFieldmap

Returns a new instance of FieldsWithCustomFieldmap.

Parameters:

  • fieldmap (Hash{Symbol => Array<Symbol>}) —

    Instructions on how to combine source fields into target fields. See above for fuller explanation of Hash format expectations

  • delim (String) —

    String to use in splitting/joining the values

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

    Whether to delete source columns after values have been combined in target columns. If a target column is the same as a source column, it will not be deleted.

Since:

  • 2.9.0



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# File 'lib/kiba/extend/transforms/collapse/fields_with_custom_fieldmap.rb', line 161

def initialize(fieldmap:, delim:, delete_sources: true)
  @fieldmap = fieldmap
  @delim = delim
  @del = delete_sources
  setup_single_warning
end

Instance Method Details

#process(row) ⇒ Object

Parameters:

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

Since:

  • 2.9.0



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# File 'lib/kiba/extend/transforms/collapse/fields_with_custom_fieldmap.rb', line 169

def process(row)
  fieldmap.each do |target, sources|
    row[target] = compile_source_values(sources, row)
  end
  delete_sources(row) if del
  row
end