Class: IOStreams::Encode::Writer

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(output_stream, encoding: 'UTF-8', encode_cleaner: nil, encode_replace: nil) ⇒ Writer

A delimited stream writer that will write to the supplied output stream Written data is encoded prior to writing.

Parameters

output_stream
  The output stream that implements #write

encoding: [String|Encoding]
  Encode returned data with this encoding.
  'US-ASCII':   Original 7 bit ASCII Format
  'ASCII-8BIT': 8-bit ASCII Format
  'UTF-8':      UTF-8 Format
  Etc.
  Default: 'UTF-8'

encode_replace: [String]
  The character to replace with when a character cannot be converted to the target encoding.
  nil: Don't replace any invalid characters. Encoding::UndefinedConversionError is raised.
  Default: nil

encode_cleaner: [nil|symbol|Proc]
  Cleanse data read from the input stream.
  nil:           No cleansing
  :printable Cleanse all non-printable characters except \r and \n
  Proc/lambda    Proc to call after every read to cleanse the data
  Default: nil



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# File 'lib/io_streams/encode/writer.rb', line 41

def initialize(output_stream, encoding: 'UTF-8', encode_cleaner: nil, encode_replace: nil)
  @output_stream = output_stream
  @cleaner       = ::IOStreams::Encode::Reader.send(:extract_cleaner, encode_cleaner)

  @encoding         = encoding.nil? || encoding.is_a?(Encoding) ? encoding : Encoding.find(encoding)
  @encoding_options = encode_replace.nil? ? {} : {invalid: :replace, undef: :replace, replace: encode_replace}
end

Instance Attribute Details

#cleaner ⇒ Object (readonly)

Returns the value of attribute cleaner.



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# File 'lib/io_streams/encode/writer.rb', line 4

def cleaner
  @cleaner
end

#encoding ⇒ Object (readonly)

Returns the value of attribute encoding.



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# File 'lib/io_streams/encode/writer.rb', line 4

def encoding
  @encoding
end

Class Method Details

.open(file_name_or_io, **args) ⇒ Object

Write a line at a time to a file or stream



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# File 'lib/io_streams/encode/writer.rb', line 7

def self.open(file_name_or_io, **args)
  if file_name_or_io.is_a?(String)
    IOStreams::File::Writer.open(file_name_or_io) { |io| yield new(io, **args) }
  else
    yield new(file_name_or_io, **args)
  end
end

Instance Method Details

#<<(record) ⇒ Object

Write a line to the output stream

Example:

IOStreams.writer('a.txt', encoding: 'UTF-8') do |stream|
  stream << 'first line' << 'second line'
end



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# File 'lib/io_streams/encode/writer.rb', line 55

def <<(record)
  write(record)
  self
end

#write(data) ⇒ Object

Write a line to the output stream followed by the delimiter. Returns [Integer] the number of bytes written.

Example:

IOStreams.writer('a.txt', encoding: 'UTF-8') do |stream|
  count = stream.write('first line')
  puts "Wrote #{count} bytes to the output file, including the delimiter"
end



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# File 'lib/io_streams/encode/writer.rb', line 68

def write(data)
  return 0 if data.nil?

  data  = data.to_s
  block = data.encoding == @encoding ? data : data.encode(@encoding, @encoding_options)
  block = @cleaner.call(block) if @cleaner
  @output_stream.write(block)
end