How can I find out *who* is publishing a message in MQTT?

General
21

That would be useful :+1:

22

No visualisation yet but something to grab whole topic hierarchies - put this into a function node:

// Just a safety measure to prevent too much recursion
// Change if you have crazy deep topic hierarchies
const maxLevels = 9

function doTopic(topicsPart, keys, level =  0) {
    if (level > maxLevels) return // no infinite loops!

    let key
    if (Array.isArray(keys) && keys.length > 1) {
        // Grab the top level key (make sure it is a string)
        // MQTT topic parts could be number - don't want an accidental array
        key = `${keys.shift()}`

        // Make sure that the property exists as the next level
        if (!topicsPart[key]) topicsPart[key] = { _count: 1 }
        else topicsPart[key]._count++

        // Recurse to the next level
        doTopic(topicsPart[key], keys, level++)
    } else {
        // Must be at the end of the topic chain
        if (!Array.isArray) keys = [keys] // make sure it is an array

        // MQTT topic parts could be number
        key = `${keys[0]}` // make sure it is a string
        
        if (!topicsPart[key]) topicsPart[key] = { _count: 0 }
        topicsPart[key]._count++
        topicsPart[key]._value = msg.payload
        topicsPart[key]._userProperties = msg.userProperties
    }
}

const topics = flow.get('mqtt') ?? {}

const splitTopic = msg.topic.split('/')

doTopic(topics, splitTopic)

// flow.set('mqttTopics', topics)
flow.set('mqtt', topics)

// Don't do this with bazilions of topics!
return msg
2 Likes
23

Working here ok Julian :+1:

mqtt

1 Like
24

I just need to get round to creating a visual UI now. :woozy_face:

1 Like
25

A bit of progress made on a visualisation:

image

This is just the tree view. The values will be moved to a details pane, out of the tree. Also, this is just the initial display, it is built from the cached data in Node-RED. A bit of tweaking of the CSS still needed.

The cache is triggered when you first load the page. I'm using UIBUILDER of course, so the cache replay is automatic.

I then need to do the individual record updates.

Here is the flow that generates everything.

image
image1212×429 40.2 KB

2 Likes
26

Looks good.
I was thinking of doing something like that (but not made any progress).
I intended to show a count of messages per topic rather than the most recent value because occasionally I suspect something has gone wrong and MQTT may be in a loop.

3 Likes
27

I'd been thinking about it on and off since MQTT v5 landed and the author of MQTT Explorer had announced that he wasn't continuing development.

This was the impetus I needed. Along with the fact that UIBUILDER now makes doing dynamic interfaces so much easier even without a framework. No need to mess with the weirdness of the DOM. :slight_smile:

28

More progress, actually a lot easier than expected:

Animation1

Less than 150 lines of front-end code including plenty of blank lines and comments.

4 Likes
29

So sorry, this is something you wrote?

Wow!

I could only aspire to that.

(Where could I get it?)

30

Something I'm working on that was triggered by this thread. :slight_smile:

Actually, thanks to the help that both Node-RED and UIBUILDER give, it isn't anywhere near as bad as it might appear. :slight_smile:

It is still a work in progress - rather than pollute this thread even further, why don't I start a new thread. Eventually I will publish the full example in the Flows but people might be interested in following along.

3 Likes
31

The other thread:

32

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.