do-red/src/utils/doHelper.js

A do-node and corresponding return-node for creating loops and task-lists.

const initNextValue = (msg, config, tasks, RED) => {
  const _do = msg._do
  _do.index = _do.index + 1
  delete _do.valueDeleted
  // first time the task stack has values from general _do initaliziation
  if (!_do.stack.length) _do.isFirstMsg = false
  _do.stack = [...tasks].reverse()

  if (_do.collectionType === 'Array') {
    if (config.yield === 'value') {
      msg.payload = _do.collection[_do.index]
    } else {
      msg.payload = { [_do.index]: _do.collection[_do.index] }
    }
  } else if (_do.collectionType === 'Set') {
    msg.payload = _do.setIterator.next().value
    _do.currentSetValue = RED.util.cloneMessage(msg.payload)
  } else if (_do.collectionType === 'Object' || _do.collectionType === 'Map') {
    const currentKey = _do.keys[_do.index]
    let currentValue
    if (_do.collectionType === 'Object') currentValue = _do.collection[currentKey]
    else if (_do.collectionType === 'Map') currentValue = _do.collection.get(currentKey)

    if (config.yield === 'keyValue') {
      msg.payload = { [currentKey]: currentValue }
    } else if (config.yield === 'key') {
      msg.payload = currentKey
    } else if (config.yield === 'value') {
      msg.payload = currentValue
    } else {
      throw new Error("Can't put value into payload (" + config.yield + ' is not valid for Yield).')
    }
  } else {
    throw new Error('No valid collection set!')
  }
  return msg
}

const initEachDo = (RED, msg, node, config, _do) => {
  _do.index = -1
  _do.isFirstMsg = true
  _do.isLastMsg = false
  _do.eachType = config.eachType
  _do.eachPath = config.each
  _do.yieldType = config.yield

  // clone the collection and payload. The collection will always be written when done is reached.
  // if the collection is not (within) msg.payload, msg.payload will be replaced with it's original value after all tasks are done.
  if (config.eachType === 'msg') {
    _do.collection = RED.util.cloneMessage(RED.util.getObjectProperty(msg, _do.eachPath))
  } else {
    _do.collection = RED.util.evaluateNodeProperty(config.each, config.eachType, node, msg)
  }
  _do.payload = RED.util.cloneMessage(msg.payload)
  return _do
}

const handleDone = (RED, msg, config, send, done) => {
  // return original payload after each is done
  // if (msg?._do?.payload) { // use optional chaining when latest supported version from node-red is allowing
  if (msg._do && msg._do.payload) {
    msg.payload = msg._do.payload
  }
  // get parent do or delete if done
  // if (msg?._do?._do) {
  if (msg._do && msg._do._do) {
    msg._do = msg._do._do
  } else {
    delete msg._do
  }
  // send to output or event to other do-node
  if (config.doneOutput) {
    const out = new Array(config.outputs - 1)
    out.push(msg) // must be last output
    send(out)
  // } else if (msg?._do?.returnTo) {
  } else if (msg._do && msg._do.returnTo) {
    // if we return to a previous do-node then a task was completed
    if (Array.isArray(msg._do.stack)) msg._do.stack.pop()
    const event = 'do:' + msg._do.returnTo
    msg._event = event
    RED.events.emit(event, msg)
  }
  if (done) return done()
}

const checkCollectionType = (config, collection) => {
  if (typeof collection === 'undefined') throw new Error(`Collection ${config.eachType}.${config.each} is undefined!`)
  else if (Array.isArray(collection)) return 'Array'
  // instanceof Set/Map seems not to work. Maybe proxy variable through Node-Red?
  // else if (collection?.constructor?.name === 'Map') return 'Map'
  // else if (collection?.constructor?.name === 'Set') return 'Set'
  else if (collection.constructor && collection.constructor.name === 'Map') return 'Map'
  else if (collection.constructor && collection.constructor.name === 'Set') return 'Set'
  else if (!!collection && typeof collection === 'object' && Array.isArray(collection) === false) return 'Object'
  throw new Error(`Collection ${config.eachType}.${config.each} could not identified!`)
}

module.exports = {
  initNextValue,
  initEachDo,
  handleDone,
  checkCollectionType
}