prisme-flow/nodes/bridge/binary/lib/BinaryNode.js

prisme platform flow engine

'use strict'
var RED
var packet = require('packet')
var typeOf = require('typeof')

function BinaryNode (node, pattern) {
  var parser, serializer

  this.node = node

  // create parser object and define pattern
  parser = packet.createParser()
  parser.packet('payload', pattern)
  this.parser = parser

  // create serializer with the same pattern
  serializer = parser.createSerializer()
  this.serializer = serializer
}

BinaryNode.prototype.handleInputEvent = function (msg) {
  if (msg.hasOwnProperty('payload')) {
    var t = typeOf(msg.payload)
    if (t == 'object') { // serialize object
      this.serializer.serialize('payload', msg.payload)
      var buf = new Buffer(this.serializer.sizeOf)
      this.serializer.write(buf)
      this._sendMessage(buf, msg)
    } else if (Buffer.isBuffer(msg.payload)) { // parse buffer
      var foo = this
      this.parser.extract('payload', function (result) {
        if (JSON.stringify(result) !== '{}') {
          foo._sendMessage(result, msg)
        }
      })
      this.parser.parse(msg.payload)
    } else {
      throw new Error('invalid input')
    }
  }
}

BinaryNode.prototype.handleCloseEvent = function () {}

BinaryNode.prototype._sendMessage = function (payload, msg) {
  // create message
  var m = RED.util.cloneMessage(msg)
  m.payload = payload
  m.original = msg.payload
  this.node.send(m)
}

module.exports = function (runtime) {
  RED = runtime
  return BinaryNode
}