Class: Uncsv::Header

Inherits:
Object
  • Object
show all
Defined in:
lib/uncsv/header.rb

Overview

A parsed CSV header.

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(headers, config = nil) ⇒ Header

Create a new Header object

Parameters:

  • headers (Array<Array<String>>) —

    An array of header row values

  • config (Config) (defaults to: nil) —

    Configuration options. Default options if nil.



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# File 'lib/uncsv/header.rb', line 10

def initialize(headers, config = nil)
  @headers = headers
  @config = config || Config.new
  @to_a = nil
end

Class Method Details

.parse!(csv, config) ⇒ OpenStruct

Parse headers from a CSV

Parameters:

  • csv (CSV) —

    A CSV object.

  • config (Config) —

    Configuration options. Default options if nil.

Returns:

  • (OpenStruct) —

    An object with the methods header, index, and rows. header is the Uncsv::Header object. index is the next CSV row index. rows is an array of the skipped rows including the header rows.



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# File 'lib/uncsv/header.rb', line 53

def parse!(csv, config)
  index = config.header_rows.empty? ? 0 : (config.header_rows.max + 1)
  rows = read_rows(csv, index)
  headers = config.header_rows.map { |i| rows[i] }
  OpenStruct.new(
    header: new(headers, config),
    index: index,
    rows: rows
  )
end

Instance Method Details

#each {|row| ... } ⇒ Enumerator

Iterate over each header field

Yields:

  • A block to run for each header field

Yield Parameters:

  • row (String) —

    A header field

Returns:

  • (Enumerator) —

    An enumerator over header field



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# File 'lib/uncsv/header.rb', line 21

def each(&block)
  to_a.each(&block)
end

#to_a ⇒ Array

Get an array of parsed header fields

The header fields are cached, so consecutive calls to this method return the same array.

Returns:

  • (Array) —

    The array of header fields



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# File 'lib/uncsv/header.rb', line 31

def to_a
  @to_a ||= begin
    headers = nil_empty(@headers)
    headers = square(headers)
    headers = normalize(headers) if @config.normalize_headers
    headers = expand(headers)
    combined = combine(headers)
    combined = unique(combined) if @config.unique_headers
    combined
  end
end