# List of topic choices in mqtt-in
**URL:** https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001
**Category:** General
**Created:** [22 March 2021 12:30 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001 "2021-03-22T12:30:36Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@fmarzocca](https://discourse.nodered.org/u/fmarzocca)
#### Post date: [22 March 2021 12:30 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/1 "2021-03-22T12:30:36Z")
I'd like to have a fixed list of available topics for the mqtt-in node. As far as I can see, using a subflow is not option, or maybe I am missing something.
In other words, I need that the user - upon deploying the node - has not to type in the topic but should make a choice from a dropdown list.
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### Author:  [@zenofmud](https://discourse.nodered.org/u/zenofmud)
#### Post date: [22 March 2021 13:14 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/2 "2021-03-22T13:14:39Z")
The `mqtt-in` node needs the topic hardcoded. If the topics being published have a formal format that they all abide by, you code subscribe to the main topic and then filter the results with switches.
Lets say you have 5 weather stations and you want tp pick the data from station 5. If the topics were arranged like
weatherstation/office/bme280
weatherstation/home/bme280
weatherstation/farm/ds18b20
you could subscribe to 'weatherstation/#' and you would get the data from all the stations. Then you could filter it by the second level in the topic
If you haven't read the [MQTT Topics & Best Practices - MQTT Essentials: Part 5](https://www.hivemq.com/blog/mqtt-essentials-part-5-mqtt-topics-best-practices/) I suggest you spend some time and read it
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### Author:  [@fmarzocca](https://discourse.nodered.org/u/fmarzocca)
#### Post date: [22 March 2021 14:20 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/3 "2021-03-22T14:20:19Z")
I have read very well the mqtt essentials, and I know that the mqtt-in need the topic hardcoded. I was just wondering if there could be a possibility not to leave this to the user, who can mistype the topic.
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### Author:  [@zenofmud](https://discourse.nodered.org/u/zenofmud)
#### Post date: [22 March 2021 14:23 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/4 "2021-03-22T14:23:38Z")
Is the user editing the node? or are they just using a dashboard and picking from a list.
It they are picking it from a list, you can programatically limit what gets to them.
If they are editing the node then, yup tehy can mistype the topic (heck, I've done that multiple times 😁)
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### Author:  [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)
#### Post date: [22 March 2021 14:42 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/5 "2021-03-22T14:42:51Z")
This would, in my opinion, need a different node. MQTT is so flexible that adding this to the standard mqtt-in would add complexity to it that most people would not use.
The nice thing (one of many of course 😉 ) about Node-RED is that it is easy enough to create a new, more specialist node from an existing example.
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### Author:  [@knolleary](https://discourse.nodered.org/u/knolleary)
#### Post date: [22 March 2021 16:10 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/6 "2021-03-22T16:10:09Z")
You can use a subflow to do this.
1. Set the mqtt-in topic to `${TOPIC}`
2. Wrap that node in a subflow.
3. Edit the subflow properties and define a property called `TOPIC`. By expanding the row in the properties table, you can customise the UI for how the property will be shown. One of the options is a select box where you can predefine a set of options.
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### Author:  [@fmarzocca](https://discourse.nodered.org/u/fmarzocca)
#### Post date: [22 March 2021 16:39 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/7 "2021-03-22T16:39:56Z")
You made my day, Nick! Thank you.
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [5 April 2021 16:40 UTC](https://discourse.nodered.org/t/list-of-topic-choices-in-mqtt-in/43001/8 "2021-04-05T16:40:50Z")
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