Update device property via NodeRED - invalid JSON content provided

[gus]

Hi all

I’m simply trying to update a device property via NodeRED, but i’m struggling to find the right format.

My device property:

My NodeRED flow:

The code in the function:

var updatedflow = {};
updatedflow.url="https://myserver.aws.thinger.io/v3/users/"+user+"/devices/"+device+"/properties/prevInstWaterFlow";
updatedflow.headers={};
updatedflow.headers["Authorization"] = "Bearer "+token;
updatedflow.headers["content-type"] = "application/json";
updatedflow.content={
            prevInstWaterFlow:0
    }
return updatedflow;

The http component:

I keep getting the errors “invalid JSON content provided”. I tried already all combinations that i could think of, but it doesn’t work.
Instead of .content, i tried already .payload, .message, .body…

Any idea what i’m doing wrong?

Thanks!
Gus

[jaimebs]

Hi @gus

Is there any reason why you are not using the property write node?

I believe this will make it easier as the node handles the underlying communication and authorization with thinger

[gus]

Hi

I tried this indeed, but i couldn’t figure out how to have a variable in the value field? Because this is a changing value in every event. Is it possible to make it variable?

[jaimebs]

You can pass the value field from the input msg, just as you where doing with the http request node, in the field msg.payload or msg.value. Example:

msg.value = 0;
return msg;

Try it out with a simple inject flow with an inject node

Translate it then to a function node and you would be able to use a variable.

Just note that at the moment there is a bug when using msg.payload instead of msg.value and where the value is 0, so it is not possible to pass it as:

msg.payload = 0;
return msg;

Will have it fixed for the next version of the plugin.

[gus]

Okay that seems to fix it.
First i build a function like this:

And then i give it to the write property component:

Thanks!
Gus