Lua pattern in mqtt topics

Question

Here is a standard topic pattern which is used in mqtt.

"lights/hue/{device_name}/get/sensing"

How could I use the regular expression to format this topic pattern with a real device name.

I am not very into the regular expression, so what I would need is a function to make a topic given a device name.

for example,

pattern : "lights/hue/{device_name}/get/sensing"
input : name = 'device123'
output: "lights/hue/device123/get/sensing"

Currently I am using the lua, would someone help me?

Please show what you tried and please limit to one language. Since you are not using Swift/Objective-C, the `nsregularexpression` tag can be removed. — Wiktor Stribiżew, Nov 22 '16 at 07:38
`var output = s.replace("{device_name}", name)` - haven't you really tried that? — Wiktor Stribiżew, Nov 22 '16 at 07:55

score 2 · Accepted Answer · edited Nov 22 '16 at 23:30

2

Assuming Lua:

pattern = "lights/hue/{device_name}/get/sensing"
name = "device123"
output = string.gsub(pattern, "{device_name}", name )
print(output)

There is no need for a regular expression. Simple replacement will do the job.

edited Nov 22 '16 at 23:30

Wiktor Stribiżew

answered Nov 22 '16 at 08:00

infotoni91

1 Answers1