Class: JsonCsv

Inherits:
Object
  • Object
show all
Defined in:
lib/json-csv.rb

Constant Summary collapse

VERSION = 
"0.5.1"
VERSION_DATE = 
"2017-06-25"
DEFAULT_OPTS = 
{
  input_file: "-",
  output_file: "-",
  source_encoding: "json",
  tmpdir: ENV['TMPDIR'] || "/tmp",
  debug: false,
  depth: -1,
  line_ending: "\r\n",
}

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts) ⇒ JsonCsv

Returns a new instance of JsonCsv.



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# File 'lib/json-csv.rb', line 99

def initialize(opts)
  @opts = DEFAULT_OPTS.merge(opts)
end

Class Method Details

.convert_csv_to_json(opts) ⇒ Object 



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# File 'lib/json-csv.rb', line 94

def convert_csv_to_json(opts)
  self.new(opts).convert_csv_to_json()
end

.convert_json_to_csv(opts) ⇒ Object 



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# File 'lib/json-csv.rb', line 90

def convert_json_to_csv(opts)
  self.new(opts).convert_json_to_csv()
end

.new_from_argv(argv) ⇒ Object 



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# File 'lib/json-csv.rb', line 32

def new_from_argv(argv)
  opts = DEFAULT_OPTS

  OptionParser.new do |op|
    op.banner = <<-EOT
  Converts JSON to CSV, and vice versa.
  Usage: #{$0} [options] [--] [input-file [output-file]]
    EOT

    op.on("-i input-file", "--input input-file", "Input file (default STDIN)") do |input_file|
      opts[:input_file] = input_file
    end

    op.on("-o output-file", "--output output-file", "Output file (default STDOUT)") do |output_file|
      opts[:output_file] = output_file
    end

    op.on("-s json|csv", "--source-encoding json|csv", "Encoding of input file (default json)") do |source|
      opts[:source_encoding] = source
    end

    op.on("-d depth", "--depth depth", "Maximum depth of JSON-to-CSV conversion (default -1, unlimited)") do |depth|
      opts[:depth] = depth.to_i
      opts[:depth] += 1 if opts[:depth] > 0  # this is a fudge to use -1 as infinity
    end

    op.on("-e crlf|cr|lf", "--line-ending crlf|cr|lf", "Line endings for output file (default crlf).") do |ending|
      opts[:line_ending] = {"crlf" => "\r\n", "cr" => "\r", "lf" => "\n"}[ending]
      if !opts[:line_ending]
        STDERR.puts "Invalid line ending '#{ending}'.  Valid choices: crlf cr lf"
        exit 1
      end
    end

    op.on_tail("--debug", "Turn debugging messages on") do
      opts[:debug] = true
    end

    op.on_tail("--version", "Print version info and exit") do
      puts "json-csv version #{VERSION} (#{VERSION_DATE})"
      puts "https://github.com/appcues/json-csv"
      exit
    end

    op.on_tail("-h", "--help", "Show this message and exit") do
      puts op.to_s
      exit
    end

  end.parse!(argv)


  opts[:input_file] = argv.shift if argv.count > 0
  opts[:output_file] = argv.shift if argv.count > 0

  self.new(opts)
end

Instance Method Details

#convert_csv_to_json(opts = {}) ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/json-csv.rb', line 161

def convert_csv_to_json(opts = {})
  raise NotImplementedError
end

#convert_json_to_csv(opts = {}) ⇒ Object 



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# File 'lib/json-csv.rb', line 116

def convert_json_to_csv(opts = {})
  opts = @opts.merge(opts)

  ## First pass -- create CSV headers from JSON input
  input_fh = nil
  tmp_fh = nil
  tmp_filename = nil
  data_filename = nil

  if opts[:input_file] == "-"
    input_fh = STDIN
    data_filename = tmp_filename = "#{opts[:tmpdir]}/json-csv-#{$$}.tmp"
    debug(opts, "STDIN will be written to #{tmp_filename}.")
    tmp_fh = File.open(data_filename, "w")
  else
    input_fh = File.open(opts[:input_file], "r")
    data_filename = opts[:input_file]
  end

  debug(opts, "Getting headers from JSON data.")
  headers = get_headers_from_json(input_fh, tmp_fh, opts[:depth])

  input_fh.close
  tmp_fh.close if tmp_fh


  ## Second pass -- write CSV data from JSON input
  data_fh = File.open(data_filename, "r")
  output_fh = nil

  if opts[:output_file] == "-"
    output_fh = STDOUT
  else
    output_fh = File.open(opts[:output_file], "w")
  end

  debug(opts, "Writing CSV output.")
  output_csv(headers, data_fh, output_fh)
  data_fh.close
  output_fh.close

  debug(opts, "Removing #{tmp_filename}.")
  File.unlink(tmp_filename) if tmp_filename
end

#run(opts = {}) ⇒ Object 



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# File 'lib/json-csv.rb', line 103

def run(opts = {})
  opts = @opts.merge(opts)
  enc = opts[:source_encoding]
  if enc == "json"
    convert_json_to_csv()
  elsif enc == "csv"
    convert_csv_to_json()
  else
    STDERR.puts "no such source encoding '#{enc}'"
    exit 1
  end
end