index.js

var spawn = require('child_process').spawn
var fdf = require('./fdf.js')
var _ = require('lodash')
var iconv = require('iconv-lite')
var fs = require('fs')

var pdffiller = {

  mapForm2PDF: function (formFields, convMap) {
    var tmpFDFData = this.convFieldJson2FDF(formFields)
    tmpFDFData = _.mapKeys(tmpFDFData, function (value, key) {
      if (!convMap.has(key)) {
        return key
      }
      return convMap[key]
    })

    return tmpFDFData
  },

  convFieldJson2FDF: function (fieldJson) {
    var _keys = _.map(fieldJson, 'title')
    var _values = _.map(fieldJson, 'fieldValue')

    _values = _.map(_values, function (val) {
      if (val === true) {
        return 'Yes'
      } else if (val === false) {
        return 'Off'
      }
      return val
    })

    var jsonObj = _.zipObject(_keys, _values)

    return jsonObj
  },

  generateFieldJson: function (sourceFile, nameRegex) {
    var regName = /FieldName: ([^\n]*)/
    var regType = /FieldType: ([A-Za-z\t .]+)/
    var regFlags = /FieldFlags: ([0-9\t .]+)/
    var fieldArray = []
    var currField = {}

    if (nameRegex !== null && (typeof nameRegex) === 'object') regName = nameRegex

    return new Promise(function (resolve, reject) {
      var childProcess = spawn('pdftk', [sourceFile, 'dump_data_fields_utf8'])
      var output = ''

      childProcess.on('error', function (err) {
        console.log('pdftk exec error: ' + err)
        reject(err)
      })

      childProcess.stdout.on('data', function (data) {
        output += data
      })

      childProcess.stdout.on('end', function () {
        var fields = output.split('---').slice(1)

        fields.forEach(function (field) {
          currField = {}
          currField['title'] = field.match(regName)[1].trim() || ''

          if (field.match(regType)) {
            currField['fieldType'] = field.match(regType)[1].trim() || ''
          } else {
            currField['fieldType'] = ''
          }

          if (field.match(regFlags)) {
            currField['fieldFlags'] = field.match(regFlags)[1].trim() || ''
          } else {
            currField['fieldFlags'] = ''
          }

          currField['fieldValue'] = ''
          fieldArray.push(currField)
        })

        resolve(fieldArray)
      })
    })
  },

  generateFDFTemplate: function (sourceFile, nameRegex) {
    return new Promise(function (resolve, reject) {
      this.generateFieldJson(sourceFile, nameRegex).then(function (formFields) {
        var _keys = _.map(formFields, 'title')
        var _values = _.map(formFields, 'fieldValue')
        var jsonObj = _.zipObject(_keys, _values)

        resolve(jsonObj)
      }).catch(function (err) {
        reject(err)
      })
    }.bind(this))
  },

  fillFormWithOptions: function (sourceFile, fieldValues, shouldFlatten) {
    var promised = new Promise(function (resolve, reject) {
      // Generate the data from the field values.
      // var randomSequence = Math.random().toString(36).substring(7)
      // var currentTime = new Date().getTime()
      var FDFinput = fdf.createFdf(fieldValues)
      var FDFinputString = iconv.decode(FDFinput, 'utf-8')
      FDFinput = iconv.encode(FDFinputString, 'ISO-8859-1')

      var args = [sourceFile, 'fill_form', '-', 'output', '-']
      if (shouldFlatten) {
        args.push('flatten')
      }

      var childProcess = spawn('pdftk', args)

      childProcess.stderr.on('data', function (err) {
        console.log('pdftk exec error: ' + err)
        reject(err)
      })

      function sendData (data) {
        childProcess.stdout.pause()
        childProcess.stdout.unshift(data)
        resolve(childProcess.stdout)
        childProcess.stdout.removeListener('data', sendData)
      };

      childProcess.stdout.on('data', sendData)

      // now pipe FDF to pdftk
      childProcess.stdin.write(FDFinput)
      childProcess.stdin.end()
    })

    // bind convenience method toFile for chaining
    promised.toFile = toFile.bind(null, promised)
    return promised
  },

  fillFormWithFlatten: function (sourceFile, fieldValues, shouldFlatten) {
    return this.fillFormWithOptions(sourceFile, fieldValues, shouldFlatten)
  },

  fillForm: function (sourceFile, fieldValues) {
    return this.fillFormWithFlatten(sourceFile, fieldValues, true)
  }

}

/**
 * convenience chainable method for writing to a file (see examples)
 **/
function toFile (promised, path) {
  return new Promise(function (resolve, reject) {
    promised.then(function (outputStream) {
      var output = fs.createWriteStream(path)

      outputStream.pipe(output)
      outputStream.on('close', function () {
        output.end()
        resolve()
      })
    }).catch(function (error) {
      reject(error)
    })
  })
}

module.exports = pdffiller