Flow Dev Guideline

This page is for discussing about how to make Flow Dev Guideline.

You can check the original contents at HERE.

Designing a flow

Designing messages

・Overview and purpose of this chapter ・Brief description of Node-RED objects ・Necessity of making flow on the premise that other users will reuse ・Proper design with understanding the structure of the flow

Parameter that stores data shared between nodes

・Do not make multiple nodes use same property ・Importance of dividing data processed by node(msg.payload property) and controlling feature of node(msg.). ・How to prevent

Parameters that control the functionality of a unique node

・Recommended pattern of parameter setting

In a node to which multiple messages with different types are input, add tag information for identification to each message.

・Necessity of tag due to the fact that there is only one input port of node

Store a large amount of data in persistent storage outside Node-RED and reference the data.

・Points to note when handling large amounts of data

Processing depending on the order of arrival of messages

・The order of arrival of messages when processing multiple messages

// Accumulation of messages
var msgs = context.get('messages') || [];
msgs.push(msg);
if(msgs.length === ...) {
  ... // Process messages
}
context.set('messages', msgs);

Design pattern

Pattern regarding the structure between flows

Facade pattern