Class: IOStreams::Row::Writer

Inherits:
Object
  • Object
show all
Defined in:
lib/io_streams/row/writer.rb

Overview

Example:

IOStreams.row_writer do |stream|
  stream << ['name', 'address', 'zipcode']
  stream << ['Jack', 'Somewhere', 12345]
  stream << ['Joe', 'Lost', 32443]
end

Output:

...

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(delimited, columns: nil, **args) ⇒ Writer

Create a Tabular writer that takes individual rows as arrays.

Parameters

delimited: [#<<]
  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

  columns: nil, allowed_columns: nil, required_columns: nil, skip_unknown: true)



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# File 'lib/io_streams/row/writer.rb', line 43

def initialize(delimited, columns: nil, **args)
  @tabular   = IOStreams::Tabular.new(columns: columns, **args)
  @delimited = delimited

  # Render header line when `columns` is supplied.
  delimited << @tabular.render_header if columns && @tabular.requires_header?
end

Class Method Details

.open(file_name_or_io, delimiter: $/, encoding: nil, encode_cleaner: nil, encode_replace: nil, **args) ⇒ Object

Write a record as a Hash at a time to a file or stream.



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# File 'lib/io_streams/row/writer.rb', line 16

def self.open(file_name_or_io, delimiter: $/, encoding: nil, encode_cleaner: nil, encode_replace: nil, **args)
  if file_name_or_io.is_a?(String)
    IOStreams.line_writer(file_name_or_io,
                          delimiter:      delimiter,
                          encoding:       encoding,
                          encode_cleaner: encode_cleaner,
                          encode_replace: encode_replace
    ) do |io|
      yield new(io, **args)
    end
  else
    yield new(file_name_or_io, **args)
  end
end

Instance Method Details

#<<(array) ⇒ Object

Supply a hash or an array to render

Raises:

  • (ArgumentError) 


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# File 'lib/io_streams/row/writer.rb', line 52

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
    @delimited << @tabular.render_header
  else
    @delimited << @tabular.render(array)
  end
end