Method: Jinx::CsvIO#initialize

Defined in:
lib/jinx/csv/csvio.rb

#initialize(dev, opts = nil) {|value, info| ... } ⇒ CsvIO

Creates a new CsvIO for the specified source file. If a converter block is given, then it is added to the CSV converters list.

Parameters:

  • dev (String, IO) —

    the CSV file or stream to open

  • opts (Hash) (defaults to: nil) —

    the open options

Options Hash (opts):

  • :mode (String) —

    the input mode (default r)

  • :headers (String) —

    the input field headers

Yields:

  • (value, info) —

    converts the input value

Yield Parameters:

  • value (String) —

    the input value

  • info —

    the current field’s FasterCSV FieldInfo metadata

Raises:

  • (ArgumentError) —

    if the input is nil



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# File 'lib/jinx/csv/csvio.rb', line 84

def initialize(dev, opts=nil, &converter)
  raise ArgumentError.new("CSV input argument is missing") if dev.nil?
  # the CSV file open mode
  mode = Options.get(:mode, opts, 'r')
  # the CSV headers option; can be boolean or array
  hdr_opt = Options.get(:headers, opts)
  # there is a header record by default for an input CSV file
  hdr_opt ||= true if mode =~ /^r/
  # make parent directories if necessary for an output CSV file
  File.makedirs(File.dirname(dev)) if String == dev and mode =~ /^w/
  # if headers aren't given, then convert the input CSV header record names to underscore symbols
  hdr_cvtr = :symbol unless Enumerable === hdr_opt
  # make a custom converter
  custom = Proc.new { |value, info| convert(value, info, &converter) }
  # collect the options
  csv_opts = {:headers => hdr_opt, :header_converters => hdr_cvtr, :return_headers => true, :write_headers => true, :converters => custom}
  # Make the parent directory if necessary.
  FileUtils.mkdir_p(File.dirname(dev)) if String === dev and mode !~ /^r/
  # open the CSV file
  @csv = String === dev ? FasterCSV.open(dev, mode, csv_opts) : FasterCSV.new(dev, csv_opts)
  # the header => field name hash:
  # if the header option is set to true, then read the input header line.
  # otherwise, parse an empty string which mimics an input header line.
  hdr_row = case hdr_opt
  when true then
    @csv.shift
  when Enumerable then
    ''.parse_csv(:headers => hdr_opt, :header_converters => :symbol, :return_headers => true)
  else
    raise ArgumentError.new("CSV headers option value not supported: #{hdr_opt}")
  end
  # The field value accessors consist of the header row headers converted to a symbol.
  @accessors = hdr_row.headers
  # The field names consist of the header row values.
  @field_names = @accessors.map { |sym| hdr_row[sym] }
  # the header name => symbol map
  @hdr_sym_hash = hdr_row.to_hash.invert
end