If you are using a node like the change node then it defaults to payload, but you can change any property by editing the appropriate field as shown below: Likewise the message topic can be accessed using: var topic= msg.topic Īnd can be modified using: msg.topic= topic The message payload can be accessed using: var payload= msg.payload Īnd can be modified using: msg.payload=payload You access the msg properties just like you do any JavaScript object. There is also the very versatile function node, but using it requires writing JavaScript code.
You can find out more of what they do by dragging them onto the flow and then viewing the info tab associated with them. The main nodes are change, split, join, switch Node-Red provides various core nodes that can change the messages object without you having to write any JavaScript code. Msg object properties can be any valid JavaScript type e.g.
The _ msgid property is a message identifier added by node-red and can be used to track message objects. You will see that is has the following properties or partsĪ msg object that originates from an MQTT input node has the following properties: If you Look at the message object properties of the the inject node. You can see the message properties by sending the msg to the debug node.īy default the debug node will display the msg.payload property, but you can edit the debug node to display all of the message properties ( complete message object). The Msg Object is a standard JavaScript object and has several existing properties or parts depending on where it originated. Nodes exchange data between each other using the msg object.Įach node receives the message object from the previous node, and can then pass this message object onto the next node in the flow.
#Red alarm expression series
A node red flow consists of a series of interconnected nodes.(wired nodes).Īll nodes must have an input and can have 0 or multiple outputs.
0 kommentar(er)
