Sequence Processing function Node-RED nodes

Sequence processing function Node-RED nodes including map, reduce and filter.

There are 5 nodes in this project.

1. capture node ... Capture a message and append it into an array, emit the array with the given trigger conditions
2. stats node ... Provide statistical processing function applied to an array in msg.payload
3. map node ... Provide map function applied to an array in msg.payload
4. reduce node ... Provide reduce function applied to an array in msg.payload
5. filter node ... Provide filter function applied to an array in msg.payload

Each node handles and manipulates an array in msg.payload.

You can use existing split node and function node in conjunction with the above nodes in order to process a sequence of messages.

Installation

cd ~/.node-red
npm install node-red-contrib-sequence-functions

Example flow

You can try the following flow for testing the node behaviors after installing this project.

[
    {
        "id": "8cefb4ce.83e7c",
        "type": "tab",
        "label": "seuqence-processing example"
    },
    {
        "id": "5d92a885.d883",
        "type": "inject",
        "z": "8cefb4ce.83e7c",
        "name": "value = 1",
        "topic": "",
        "payload": "1",
        "payloadType": "num",
        "repeat": "",
        "crontab": "",
        "once": false,
        "x": 100,
        "y": 120,
        "wires": [
            [
                "7797567f.19dad8"
            ]
        ]
    },
    {
        "id": "702dfed0.306c38",
        "type": "inject",
        "z": "8cefb4ce.83e7c",
        "name": "value = 2.5",
        "topic": "",
        "payload": "2.5",
        "payloadType": "num",
        "repeat": "",
        "crontab": "",
        "once": false,
        "x": 100,
        "y": 160,
        "wires": [
            [
                "7797567f.19dad8"
            ]
        ]
    },
    {
        "id": "d2559185.9c8548",
        "type": "inject",
        "z": "8cefb4ce.83e7c",
        "name": "value = 8.9",
        "topic": "",
        "payload": "8.9",
        "payloadType": "num",
        "repeat": "",
        "crontab": "",
        "once": false,
        "x": 100,
        "y": 240,
        "wires": [
            [
                "7797567f.19dad8"
            ]
        ]
    },
    {
        "id": "7797567f.19dad8",
        "type": "capture",
        "z": "8cefb4ce.83e7c",
        "name": "",
        "size": 10,
        "period": 30,
        "interval": "5",
        "onNewMessage": false,
        "x": 320,
        "y": 160,
        "wires": [
            [
                "f3dc3dd5.38d06",
                "ce0e161c.9552d"
            ]
        ]
    },
    {
        "id": "f3dc3dd5.38d06",
        "type": "map",
        "z": "8cefb4ce.83e7c",
        "name": "map: value = value * 2",
        "topic": "",
        "valueProperty": "payload",
        "readFromProperty": true,
        "mapFunctionExpr": "x * 2",
        "x": 340,
        "y": 240,
        "wires": [
            [
                "3ca5b242.4e56ce",
                "7a815652.6ccf4"
            ]
        ]
    },
    {
        "id": "3ca5b242.4e56ce",
        "type": "filter",
        "z": "8cefb4ce.83e7c",
        "name": "filter: < 10",
        "topic": "",
        "rules": [
            {
                "t": "lt",
                "v": "10",
                "vt": "num"
            }
        ],
        "checkall": "true",
        "x": 320,
        "y": 320,
        "wires": [
            [
                "31ba0b3d.32e42c",
                "5615b429.0884ec",
                "9dbf1b97.4b7b6"
            ]
        ]
    },
    {
        "id": "31ba0b3d.32e42c",
        "type": "stats",
        "z": "8cefb4ce.83e7c",
        "name": "",
        "topic": "",
        "statsFunction": "sum",
        "x": 320,
        "y": 480,
        "wires": [
            [
                "57b288a9.608718"
            ]
        ]
    },
    {
        "id": "5615b429.0884ec",
        "type": "reduce",
        "z": "8cefb4ce.83e7c",
        "name": "reduce: x - a",
        "topic": "",
        "reduceFunctionExpr": "x - a",
        "reduceRight": false,
        "x": 330,
        "y": 400,
        "wires": [
            [
                "3b1affad.3cc338"
            ]
        ]
    },
    {
        "id": "ce0e161c.9552d",
        "type": "debug",
        "z": "8cefb4ce.83e7c",
        "name": "capture result",
        "active": false,
        "console": "false",
        "complete": "payload",
        "x": 580,
        "y": 160,
        "wires": []
    },
    {
        "id": "7a815652.6ccf4",
        "type": "debug",
        "z": "8cefb4ce.83e7c",
        "name": "map result",
        "active": false,
        "console": "false",
        "complete": "payload",
        "x": 570,
        "y": 240,
        "wires": []
    },
    {
        "id": "9dbf1b97.4b7b6",
        "type": "debug",
        "z": "8cefb4ce.83e7c",
        "name": "filter result",
        "active": false,
        "console": "false",
        "complete": "payload",
        "x": 570,
        "y": 320,
        "wires": []
    },
    {
        "id": "3b1affad.3cc338",
        "type": "debug",
        "z": "8cefb4ce.83e7c",
        "name": "reduce result",
        "active": false,
        "console": "false",
        "complete": "payload",
        "x": 570,
        "y": 400,
        "wires": []
    },
    {
        "id": "57b288a9.608718",
        "type": "debug",
        "z": "8cefb4ce.83e7c",
        "name": "stats result",
        "active": true,
        "console": "false",
        "complete": "payload",
        "x": 570,
        "y": 480,
        "wires": []
    },
    {
        "id": "5f2902ae.f4c61c",
        "type": "inject",
        "z": "8cefb4ce.83e7c",
        "name": "reset",
        "topic": "clear",
        "payload": "",
        "payloadType": "date",
        "repeat": "",
        "crontab": "",
        "once": false,
        "x": 90,
        "y": 280,
        "wires": [
            [
                "7797567f.19dad8"
            ]
        ]
    },
    {
        "id": "f8b5e4f5.463708",
        "type": "inject",
        "z": "8cefb4ce.83e7c",
        "name": "emit",
        "topic": "capture",
        "payload": "",
        "payloadType": "date",
        "repeat": "",
        "crontab": "",
        "once": false,
        "x": 90,
        "y": 320,
        "wires": [
            [
                "7797567f.19dad8"
            ]
        ]
    },
    {
        "id": "13af9743.c07731",
        "type": "inject",
        "z": "8cefb4ce.83e7c",
        "name": "value = 4.9",
        "topic": "",
        "payload": "4.9",
        "payloadType": "num",
        "repeat": "",
        "crontab": "",
        "once": false,
        "x": 100,
        "y": 200,
        "wires": [
            [
                "7797567f.19dad8"
            ]
        ]
    },
    {
        "id": "893a9b52.54ed",
        "type": "comment",
        "z": "8cefb4ce.83e7c",
        "name": "Click the following inject nodes to generate a message sequence",
        "info": "",
        "x": 230,
        "y": 80,
        "wires": []
    }
]

Revision History

• 1.1.3

  • Fix an issue where MapNode failed to evaluate object addressing syntax

• 1.1.2

  • Fix an issue where MapNode failed to emit a raw type object (always null)

• 1.1.1

  • Remove redundant dependency

• 1.1.0

  • Add a new property Convert to String into map node, which enables to convert the map function result into String

• 1.0.0

  • Initial release