class IOStreams::Row::Writer

Example:

IOStreams.path("file.csv").writer(:array) do |stream|
  stream << ['name', 'address', 'zipcode']
  stream << ['Jack', 'Somewhere', 12345]
  stream << ['Joe', 'Lost', 32443]
end

Public Class Methods

file(file_name, original_file_name: file_name, delimiter: $/, **args) { |new(io, original_file_name: original_file_name, **args, &block)| ... } click to toggle source

When writing to a file also add the line writer stream

# File lib/io_streams/row/writer.rb, line 23
def self.file(file_name, original_file_name: file_name, delimiter: $/, **args, &block)
  IOStreams::Line::Writer.file(file_name, original_file_name: original_file_name, delimiter: delimiter) do |io|
    yield new(io, original_file_name: original_file_name, **args, &block)
  end
end
new(line_writer, columns: nil, original_file_name: nil, **args) click to toggle source

Create a Tabular writer that takes individual rows as arrays.

Parameters

line_writer: [#<<]
  Anything that accepts a line / record at a time when #<< is called on it.

format: [Symbol]
  :csv, :hash, :array, :json, :psv, :fixed

For all other parameters, see Tabular::Header.new
# File lib/io_streams/row/writer.rb, line 39
def initialize(line_writer, columns: nil, original_file_name: nil, **args)
  raise(ArgumentError, "Stream must be a IOStreams::Line::Writer or implement #<<") unless line_writer.respond_to?(:<<)

  @tabular     = IOStreams::Tabular.new(columns: columns, file_name: original_file_name, **args)
  @line_writer = line_writer

  # Render header line when `columns` is supplied.
  line_writer << @tabular.render_header if columns && @tabular.requires_header?
end
stream(line_writer, **args) { |line_writer| ... } click to toggle source

Write a record from an Array at a time to a stream.

Note:

  • The supplied stream must already be a line stream, or a stream that responds to :<<

# File lib/io_streams/row/writer.rb, line 15
def self.stream(line_writer, **args)
  # Pass-through if already a row writer
  return yield(line_writer) if line_writer.is_a?(self.class)

  yield new(line_writer, **args)
end

Public Instance Methods

<<(array) click to toggle source

Supply a hash or an array to render

# File lib/io_streams/row/writer.rb, line 50
def <<(array)
  raise(ArgumentError, "Must supply an Array") unless array.is_a?(Array)

  if @tabular.header?
    # If header (columns) was not supplied as an argument, assume first line is the header.
    @tabular.header.columns = array
    @line_writer << @tabular.render_header
  else
    @line_writer << @tabular.render(array)
  end
end