Get notified when specific parts of my data change aka "the empty fridge app"

[bjdmeest]

The empty fridge app

Pitch

• We can imagine that we can use Solid pods to store any kind of data, i.e., our recently listened songs, our location history, or the contents of our fridge
• For services to run on top of that, we need a notification system that can act on top of those contents, e.g. 'when products X, Y, or Z are lower than y items, notify me that I should go to the store'

Desired solution

• a "Notifying Service" that has access to specific resource(s) in my solid pod
  • this one has at least one "Running query" that reacts on 'result changes'
  • This running query could be cronjob-like (pull), but could also be notified every time the source resources change and run on demand (push). I personally prefer the second option, but not sure that's possible yet.

Acceptance criteria

• I want to see an example app that shows me the current status of my fridge (A-OK vs 'you need more X')
• I want (via the same or another app) to change the data of my fridge pod ('I am eating one chocolate pudding')
• I want automagically the current status of my fridge updated ('you need more chocolate pudding')

Pointers

• LDN
• Mellon orchestrators

[joachimvh]

• This running query could be cronjob-like (pull), but could also be notified every time the source resources change

https://solidproject.org/TR/notifications-protocol

[phochste]

Or when sending only a notification if something specific happens (or you are user want to notify something in the world about data that has been changed or not changed or just want to say 'hey my fridge is still empty do something about it'): https://www.eventnotifications.net

[phochste]

Here is an example of choreographer (which is what we actually want)

https://github.com/eyereasoner/Koreografeye

Built along the lines of https://mellonscholarlycommunication.github.io/spec-orchestrator/

You can let the Koreografeye poll a resource periodically (typically the inbox, but it can be any RDF resource). For this resource one can define N3 rules that express desired actions that should happen (expressen in FNO policies). The implementation of these policies can be written in plain JS, Typescript.

Use-case are currently include:

• Polling LDN inboxes for AS2 notification and sending out Push notifications to mobile phones or service providers
• @woutslabbinck is working on integrating this with LDES workflows.