JOIN Node - Manual mode & Merged Object

General
1

Hi, I want to merge 2 payloads containing different fields into one with the JOIN node. I'm using the Manual mode to create a merged object. I'm facing strange through testing.

I've simplified my flow to this:

[{"id":"d28e2caa.c58df","type":"function","z":"73f2c6a9.b53548","name":"payload1","func":"msg = {\n    payload: {\n        correlationId: '012345',\n        trigger: 'trigger'\n    }\n};\n\nreturn msg;","outputs":1,"noerr":0,"x":320,"y":980,"wires":[["d6918015.cbf79","b5259e2.10e2c6"]]},{"id":"9e0f4a4e.6daf08","type":"function","z":"73f2c6a9.b53548","name":"payload2","func":"msg = {\n    payload: {\n        pictures: [\n            {\n                pictureName: '00_12_laserIn.jpeg',\n                camera:'12',\n                trigger:'laserIn'\n            },\n            {\n                pictureName: '00_13_laserOut.jpeg',\n                camera:'13',\n                trigger:'laserOut'\n            }\n        ]\n    }\n};\n\nreturn msg;","outputs":1,"noerr":0,"x":320,"y":1020,"wires":[["d6918015.cbf79","4746d0f4.b8a55"]]},{"id":"d6d1765d.d10a48","type":"inject","z":"73f2c6a9.b53548","name":"inject1","topic":"","payload":"","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":170,"y":980,"wires":[["d28e2caa.c58df"]]},{"id":"d6918015.cbf79","type":"join","z":"73f2c6a9.b53548","name":"","mode":"custom","build":"merged","property":"payload","propertyType":"msg","key":"payload","joiner":"\\n","joinerType":"str","accumulate":false,"timeout":"","count":"2","reduceRight":false,"reduceExp":"","reduceInit":"","reduceInitType":"num","reduceFixup":"","x":470,"y":1000,"wires":[["6fd97b52.2d1044"]]},{"id":"6fd97b52.2d1044","type":"debug","z":"73f2c6a9.b53548","name":"both","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":610,"y":1000,"wires":[]},{"id":"a5d0c387.50b6","type":"inject","z":"73f2c6a9.b53548","name":"inject2","topic":"","payload":"","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":170,"y":1020,"wires":[["9e0f4a4e.6daf08"]]},{"id":"4746d0f4.b8a55","type":"debug","z":"73f2c6a9.b53548","name":"down","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":470,"y":1040,"wires":[]},{"id":"b5259e2.10e2c6","type":"debug","z":"73f2c6a9.b53548","name":"up","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":470,"y":960,"wires":[]}]

join_node_manual_merged

payload1:

msg = {
    payload: {
        correlationId: '012345',
        trigger: 'trigger'
    }
};

payload2:

msg = {
    payload: {
        pictures: [
            {
                pictureName: '00_12_laserIn.jpeg',
                camera:'12',
                trigger:'laserIn'
            },
            {
                pictureName: '00_13_laserOut.jpeg',
                camera:'13',
                trigger:'laserOut'
            }
        ]
    }
};

Expected Result:

msg = {
    payload: {
        correlationId: '012345',
        trigger: 'trigger',
        pictures: [
            {
                pictureName: '00_12_laserIn.jpeg',
                camera:'12',
                trigger:'laserIn'
            },
            {
                pictureName: '00_13_laserOut.jpeg',
                camera:'13',
                trigger:'laserOut'
            }
        ]
    }
};

Tests:

  • Fire inject1 only => Debug logs 'up' and 'both' => 'both' contains only payload1 --KO--
  • Fire inject2 only => Debug logs 'down' only --OK--
  • Fire inject1 and then inject2 => Debug logs 'up' then 'both then 'down' => 'both' contains only payload1 --KO--
  • Fire inject2 and then inject1 => Debug logs 'down' then 'up' then 'both' => 'both' contains the expected result --OK--

Issues:

  • Why log 'both' is always logged when inject1 is fired?
  • How can I have the expected result

Thank you for your help

Node-RED version: 1.0.3

2

Hi @soma

The message from inject1 has 2 properties. The message from inject2 has 1 property. So in total, you have 3 properties to join. However, your Join node is configured to wait for 2 message parts - hence the unexpected result.

If you change it to 3, it does what you want.

3

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