csv/src/stringifier.coffee

CSV parser with simple api, full of options and tested against large datasets.

###

Stringifier
===========

Convert an array or an object into a CSV line.   

###
Stringifier = (csv) ->
  @csv = csv
  @
  
###

`write(line, [preserve])`
-------------------------

Write a line to the written stream. Line may be an object, an array or a string
The `preserve` argument is for the lines which are not considered as CSV data.   

###
Stringifier.prototype.write = (line, preserve) ->
  return unless line?
  # Emit the record
  unless preserve
    try @csv.emit 'record', line, @csv.state.count - 1
    catch e then return @csv.error e
    # Convert the record into a string
    line = @csv.stringifier.stringify line
  # Emit the csv
  line = "#{line}" if typeof line is 'number'
  @csv.emit 'data', line
  @csv.state.countWriten++ unless preserve
  true

###

`Stringifier(line)`
-------------------

Convert a line to a string. Line may be an object, an array or a string.

###
Stringifier.prototype.stringify = (line) ->
  return line if typeof line isnt 'object'
  columns = @csv.options.to.columns or @csv.options.from.columns
  columns = Object.keys columns if typeof columns is 'object' and columns isnt null and not Array.isArray columns
  delimiter = @csv.options.to.delimiter or @csv.options.from.delimiter
  quote = @csv.options.to.quote or @csv.options.from.quote
  escape = @csv.options.to.escape or @csv.options.from.escape
  unless Array.isArray line
    _line = []
    if columns
      for i in [0...columns.length]
        column = columns[i]
        _line[i] = if (typeof line[column] is 'undefined' or line[column] is null) then '' else line[column]
    else
      for column of line
        _line.push line[column]
    line = _line
    _line = null
  else if columns # Note, we used to have @csv.options.to.columns
    # We are getting an array but the user want specified output columns. In
    # this case, we respect the columns indexes
    line.splice columns.length
  if Array.isArray line
    newLine = if @csv.state.countWriten then @csv.options.to.rowDelimiter or "\n" else ''
    for i in [0...line.length]
      field = line[i]
      if typeof field is 'string'
        # fine 99% of the cases, keep going
      else if typeof field is 'number'
        # Cast number to string
        field = '' + field
      else if typeof field is 'boolean'
        # Cast boolean to string
        field = if field then '1' else ''
      else if field instanceof Date
        # Cast date to timestamp string
        field = '' + field.getTime()
      if field
        containsdelimiter = field.indexOf(delimiter) >= 0
        containsQuote = field.indexOf(quote) >= 0
        containsLinebreak = field.indexOf("\r") >= 0 or field.indexOf("\n") >= 0
        if containsQuote
          regexp = new RegExp(quote,'g')
          field = field.replace(regexp, escape + quote)
        if containsQuote or containsdelimiter or containsLinebreak or @csv.options.to.quoted
          field = quote + field + quote
        newLine += field
      if i isnt line.length - 1
        newLine += delimiter
    line = newLine
  line


module.exports = (csv) -> new Stringifier csv
module.exports.Stringifier = Stringifier