Is it possible to apply [Rule Chain] after [Data Converter]? - thingsboard

Question

I am currently working on a POC by using ThingsBoard PE.
Our raw data contains [Asset] [Attributes].
Data flow:
[IoT cloud] --https webhook carry raw data--> [ThingsBoard PE HTTP INTEGRATION] --uplink--> [ThingsBoard PE Data Converter]
My question is: is it possible to apply [Rule Chain] after [ThingsBoard PE Data Converter]? Therefore, the device can auto create relationship with [Asset] by the [Attribute], instead of [AssetName].
Example data after data converter process:
{
"deviceName": "ABC",
"deviceType": "temperature",
"attributes": {
"asset_id": 6 // <-- the id is used in asset attribute
},
"telemetry": {
"temperature": 39.43
}
}

Answer 1

Answering your two, separate questions:
is it possible to apply [Rule Chain] after [ThingsBoard PE Data Converter]?
Yes it is possible. Once your data is successfully integrated and you are receiving it, you can access it using the [Input] Rule Node (the default green one that is always there when you create a Rule) and route it to any other node you need.
Therefore, the device can auto create relationship with [Asset] by the [Attribute], instead of [AssetName].
So, you want the relationship to take your custom attribute and use that as the pattern that identifies the Asset you want to create the relationship from.
The PE edition already has the Create Relation Node. However, seems that as it is one is not able to do what you seek (has no option to specify custom Asset id).
However, two options you got are:
Create a Custom Rule Node that does what you want. For that try checking the Rule Node Development page from Thingsboard. You can use the Create Relation Node as base and work from there. This can be a longer solution than doing...
Enrich your incoming message's metadata, adding your desired attribute. The Create Relation Node allows you to use variables on your message's metadata in your Name and Type patterns, as seen from this screenshot I took from that node:
This allows us a workaround to what you want to do: Add a Script Transformation Node that adds attributes.asset_id to the metadata, for example as metadata.asset_id, so you can then use it as ${asset_id} on your Name and Type patterns.
For example, your Transform() method of such Script Transformation Node should look something like this:
function Transform(msg, metadata, msgType){
//assumming your desired id is msg.attributes.asset_id, add it to the metadata
metadata.asset_id = msg.attributes.asset_id;
//return the message, in your case to the Create Relation Node
return {msg: msg, metadata:metadata, msgType:msgType};
}
Finally, your Rule should be connected like this:
[Input] -> [Script Node] -> [Create Relation Node] -> [...whatever else you like]