Making a flow for a data handling application

In this section, you will create a working application (called a flow in Node-RED). Whether it is the internet of things (IoT) or server processing as a web application, the basic operation that Node-RED performs is sequentially transferring data.

Here, we'll create a flow where JSON data is generated in a pseudo manner, and the data is finally output to standard output via some nodes on Node-RED.

There are many nodes on the left-hand side of the palette. Please pay attention to the common categories here. You should be able to easily find the inject node, as shown in the following screenshot:

Figure 3.4 – Inject node

This node can inject a message into the next node. Let's get started:

1. Drag and drop it onto the palette of Flow 1 (the default flow tab).

   You will see that the node is labeled with the word timestamp. This is because its default message payload is a timestamp value. We...