Sending mqtt once character at a time

[nelgin]

Hi all,

I need to send text one character at a time, as typed, to an mqtt topic, including enter and control codes.

It seems it requires all sorts of workarounds by using input buttons and a send button.

It seems using the ui text input I can do only so much. I'm open to suggestions.

Thanks,

[E1cid]

It would be a large security hole if any website could act as a key stroke logger, I doubt this is possible from client side Javascript without some sort of browser plugin, but i could be wrong.

[nelgin]

ftelnet is able to accomplish this but I don't know the inner workings of it and it's probably way beyond my knowledge of how it all works.

[smcgann99]

Can you elaborate on the use case, it seems you want to emulate a terminal program of some sort ?

[nelgin]

Yes you could say that.

My bulletin board software allows the sysop to spy on a node. Often used for bug reporting and the like. Currently you can only spy on one node at a time. The output from each node is also published to a mqtt topic.

Now, if I want to type something back on the terminal, I would like it to be in real time. Again, each node has its own mqtt input topic that can be subscribed to to push data to the node.

I know this probably isn't something that a mqtt dashboard was supposed to do, but it would be interesting to find a workable solution.

[smcgann99]

If you set the delay on the text input to 0ms then it will only send the complete text when you press enter.

Could that fit your needs then ?

[nelgin]

It will but that's not going to work which is why I said I want it to send each character as its typed.

[E1cid]

Sending each char is easy, it other keys that is difficult, e.g. return, ctrl c, etc

[{"id":"6a0760d2438c3725","type":"ui_text_input","z":"b9860b4b9de8c8da","name":"","label":"","tooltip":"","group":"2d4fe667.28f8ba","order":12,"width":0,"height":0,"passthru":false,"mode":"text","delay":"100","topic":"topic","sendOnBlur":true,"className":"","topicType":"msg","x":140,"y":700,"wires":[["6554c0432a776f21"]]},{"id":"6554c0432a776f21","type":"change","z":"b9860b4b9de8c8da","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"$substring($$.payload, -1)","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":320,"y":700,"wires":[["fa71db22acf62d16","ccd50e05ab6af6e8"]]},{"id":"fa71db22acf62d16","type":"ui_text","z":"b9860b4b9de8c8da","group":"2d4fe667.28f8ba","order":13,"width":0,"height":0,"name":"","label":"text","format":"{{msg.payload}}","layout":"row-spread","className":"","style":false,"font":"","fontSize":16,"color":"#000000","x":510,"y":720,"wires":[]},{"id":"ccd50e05ab6af6e8","type":"debug","z":"b9860b4b9de8c8da","name":"debug 326","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":470,"y":660,"wires":[]},{"id":"2d4fe667.28f8ba","type":"ui_group","name":"demo","tab":"1caa8458.b17814","order":2,"disp":true,"width":"18","collapse":false,"className":""},{"id":"1caa8458.b17814","type":"ui_tab","name":"Demo","icon":"dashboard","order":2,"disabled":false,"hidden":false}]

[nelgin]

OK, I'll take a look. I'm not sure how to use that code you sent but I'll figure it out.

[dynamicdave]

Here's a suggestion for a 'demo flow' using @E1cid's posting above...