Class: JsonCsv

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

Constant Summary collapse

VERSION = 
"0.5.2"
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 103

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 97

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 93

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 88

def new_from_argv(argv)
  opts = parse_argv(argv)
  self.new(opts)
end

.parse_argv(argv) ⇒ Object 



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

def parse_argv(argv)
  opts = DEFAULT_OPTS

  argv = OptionParser.new do |op|
    op.banner = "Converts JSON to CSV, and vice versa.\nUsage: \#{$0} [options] [--] [input-file [output-file]]\n    EOT\n\n    op.on(\"-i input-file\", \"--input input-file\", \"Input file (default STDIN)\") do |input_file|\n      opts[:input_file] = input_file\n    end\n\n    op.on(\"-o output-file\", \"--output output-file\", \"Output file (default STDOUT)\") do |output_file|\n      opts[:output_file] = output_file\n    end\n\n    op.on(\"-s json|csv\", \"--source-encoding json|csv\", \"Encoding of input file (default json)\") do |source|\n      opts[:source_encoding] = source\n    end\n\n    op.on(\"-d depth\", \"--depth depth\", \"Maximum depth of JSON-to-CSV conversion (default -1, unlimited)\") do |depth|\n      opts[:depth] = depth.to_i\n    end\n\n    op.on(\"-e crlf|cr|lf\", \"--line-ending crlf|cr|lf\", \"Line endings for output file (default crlf).\") do |ending|\n      opts[:line_ending] = {\"crlf\" => \"\\r\\n\", \"cr\" => \"\\r\", \"lf\" => \"\\n\"}[ending]\n      if !opts[:line_ending]\n        STDERR.puts \"Invalid line ending '\#{ending}'.  Valid choices: crlf cr lf\"\n        exit 1\n      end\n    end\n\n    op.on_tail(\"--debug\", \"Turn debugging messages on\") do\n      opts[:debug] = true\n    end\n\n    op.on_tail(\"--version\", \"Print version info and exit\") do\n      puts \"json-csv version \#{VERSION} (\#{VERSION_DATE})\"\n      puts \"https://github.com/appcues/json-csv\"\n      exit\n    end\n\n    op.on_tail(\"-h\", \"--help\", \"Show this message and exit\") do\n      puts op.to_s\n      exit\n    end\n\n  end.parse(argv)\n\n  opts[:input_file] = argv.shift if argv.count > 0\n  opts[:output_file] = argv.shift if argv.count > 0\n\n  opts\nend\n"

Instance Method Details

#convert_csv_to_json(opts = {}) ⇒ Object

Raises:



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# File 'lib/json-csv.rb', line 171

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 124

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.")
  depth = opts[:depth]
  depth += 1 if depth > 0  # a fudge, in order to use -1 as infinity
  headers = get_headers_from_json(input_fh, tmp_fh, 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, opts[:line_ending])
  data_fh.close
  output_fh.close

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

#run(opts = {}) ⇒ Object

Performs the JSON-to-CSV or CSV-to-JSON conversion, as specified in opts and the options passed in during JsonCsv.new.



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# File 'lib/json-csv.rb', line 110

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