do-red/src/utils/returnHelper.js

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

const isObject = (obj) => (!!obj && typeof obj === 'object' && Array.isArray(obj) === false)

const handleEachArray = (msg) => {
  const _do = msg._do
  if (_do.yieldType === 'indexValue') {
    let newIndex = _do.index
    if (!isObject(msg.payload)) {
      throw new Error(`Error: Payload is not an object, but should replace index and value for { ${_do.index}: ${_do.collection[_do.index]} }`)
    }
    newIndex = Object.keys(msg.payload)[0]
    if (newIndex !== 'undefined' && isNaN(Number(newIndex))) {
      throw new Error(`Error: Payload key is not a number, but should replace { ${_do.index}: ${_do.collection[_do.index]} }`)
    }

    // check if deleted and and has no delete flag -> then we delete the value from the collection (else)
    if (newIndex === 'undefined' && !_do.valueDeleted) {
      // const oldValue = _do.collection[_do.index]
      _do.collection.splice(_do.index, 1)
      // _do.collection = _do.collection.filter(el => el !== oldValue) // check if works with object?!
      _do.index = _do.index - 1
      _do.valueDeleted = true
      _do.collectionLength = _do.collectionLength - 1
    // if value was removed in one task and another task wants to add it at the old position again
    } else if (_do.valueDeleted && Number(newIndex) === _do.index + 1) {
      _do.index = _do.index + 1
      _do.collectionLength = _do.collectionLength + 1
      _do.collection.splice(_do.index, 0, msg.payload[newIndex])
      delete _do.valueDeleted
    // set new index/value
    } else if (newIndex !== 'undefined') {
      _do.collection[newIndex] = msg.payload[newIndex]
      // if index was moved, old index will be undefined and not be removed
      if (Number(newIndex) !== _do.index) {
        _do.collection[_do.index] = undefined
      }
    }
  } else {
    _do.collection[_do.index] = msg.payload
  }
  return msg
}

const handleEachSet = (msg) => {
  const _do = msg._do
  // if value in Set is an object, we must have the reference of it, which seems to go lost during Node-Red (currentSetValue = set1.values().next() )
  // can't delete it with an equal looking object.
  if (typeof _do.currentSetValue === 'object') {
    const colIterator = _do.collection.values()
    for (const el of colIterator) {
      if (JSON.stringify(el) === JSON.stringify(_do.currentSetValue)) {
        _do.currentSetValue = el
        break
      }
    }
  }
  _do.collection.delete(_do.currentSetValue)
  _do.collection.add(msg.payload)
  _do.currentSetValue = msg.payload
  return msg
}

const handleEachObject = (msg, RED) => {
  const _do = msg._do
  const obj = RED.util.getMessageProperty(msg, 'msg._do.collection')
  let currentKey = _do.keys[_do.index]

  const deleteObject = () => {
    delete obj[currentKey]
    _do.keys[_do.index] = undefined
  }

  const changeObject = (newKey, newValue, onlyKey = false) => {
    if (currentKey !== newKey) {
      obj[newKey] = obj[currentKey]
      delete obj[currentKey]
      _do.keys[_do.index] = newKey
      currentKey = newKey
    }
    if (!onlyKey) obj[currentKey] = newValue
  }
  if (_do.yieldType === 'value') {
    changeObject(currentKey, msg.payload)
  } else if (_do.yieldType === 'key') {
    if (msg.payload === undefined) {
      deleteObject()
    } else {
      changeObject(msg.payload, null, true)
    }
  } else if (_do.yieldType === 'keyValue') {
    if (!isObject(msg.payload) && msg.payload !== undefined) {
      throw new Error(`Error: Payload is not an object. But should replace { ${currentKey}: ${RED.util.getObjectProperty(obj, currentKey)} }`)
    }
    if (msg.payload === undefined) {
      deleteObject()
    } else {
      const newKey = Object.keys(msg.payload)[0]
      const newValue = msg.payload[newKey]
      changeObject(newKey, newValue)
    }
  }
  return msg
}

const handleEachMap = (msg, RED) => {
  const _do = msg._do
  const thisMap = RED.util.getMessageProperty(msg, 'msg._do.collection')
  const currentKey = _do.keys[_do.index]

  if (_do.yieldType === 'value') {
    thisMap.set(currentKey, msg.payload)
  } else if (_do.yieldType === 'key') {
    if (msg.payload !== currentKey) {
      if (msg.payload !== undefined) thisMap.set(msg.payload, thisMap.get(currentKey))
      thisMap.delete(currentKey)
      _do.keys[_do.index] = msg.payload
    }
  } else if (_do.yieldType === 'keyValue') {
    if (msg.payload === undefined) {
      thisMap.delete(currentKey)
    } else {
      if (!isObject(msg.payload)) {
        throw new Error(`Error: Payload is not an object. But should replace { ${currentKey}: ${RED.util.getObjectProperty(thisMap, currentKey)} }`)
      }
      const newKey = Object.keys(msg.payload)[0]
      if (newKey !== currentKey) {
        thisMap.delete(currentKey)
        _do.keys[_do.index] = newKey
        thisMap.set(newKey, msg.payload[newKey])
      }
    }
  }
  return msg
}

module.exports = {
  handleEachArray,
  handleEachSet,
  handleEachObject,
  handleEachMap
}