Autocomplete MQTT topics in Node-RED

[joepavitt]

Story

As a Node-RED Developer
I want to have my MQTT topics autocompleted
So that I can build solutions integrating with my MQTT broker faster and more efficiently.

Details

There is likely to be a couple of child components here:

• Work in Node-RED
• Work in FlowFuse to pass context/information to the Node-RED Editor

Fundamentally, we want to provide auto-complete functionality in the MQTT nodes when running on FlowFuse. The autocomplete should provide suggestions from the Team's known broker hierarchy.

[knolleary]

The technical challenge here comes in two places:

1. The MQTT nodes providing a way to plugin auto-complete suggestions
2. Only apply those suggestions if they have a config node selected related to a broker we know about.

Item 1 will require work in the core of Node-RED.
Item 2 will require the plugin api provided by Node-RED to provide information on the broker selected, and for us to implement such a plugin that can retrieve valid completions from the platform.