@tonymacdonald/node-red-msg-encapsulation 0.0.4
Wrap existing message as a property in a new message or extract a previously wrapped message
A pair of simple nodes to wrap an incoming node red message into a property of a new, otherwise empty, message and to, later, unwrap the previously wrapped message. This allows the state carried in the original message to be preserved for later use while still being carried along with the message.
Example
Nodes
wrap-msg
Outputs
| output | description |
|---|---|
wrapped_msg (object) |
the entire incoming message. |
Details
The entire incoming message is wrapped into a property msg.wrapped_msg on a new otherwise empty message which is sent on the output.
unwrap-msg
Inputs
| input | description |
|---|---|
wrapped_msg (object) |
the original wrapped message object to be unwrapped. |
payload |
the payload to be added to the unwrapped message as msg.outer_payload |
Output
| output | description |
|---|---|
outer_payload |
The payload of the incoming message |
all other properties |
The properties of the original wrapped message from msg.wrapped_msg on the incoming message. |
Details
The previously wrapped message is extracted from the wrapped_msg property of the incoming message,
The payload of the incoming message is preserved as a new property outer_payload added to the unwrapped message which is sent to the output.
The outer_payload propterty on the unwrapped message allows the result of the intervening flow to be integrated with the newly unwrapped message.
If there is no wrapped_msg property on the incoming message, a catchable error is raised.
Using the wrap-msg and unwrap-msg nodes around a destructive section of the flow allows for processing on the intervening flow without owerwriting properties of the wrapped message.
