webpush-subscription-2022-flow.mmd

sequenceDiagram
  autonumber
  participant Subscribing PWA as Subscriber
  participant Browser Messaging Service
  participant Storage Metadata
  participant Subscription Service
  participant Authorization Server


    Note over Subscribing PWA, Subscription Service: Discovery
  Subscribing PWA ->>+ Storage Metadata: GET 
  Storage Metadata -->>- Subscribing PWA: 200 OK with Storage Metadata Representation
  Subscribing PWA ->>+ Subscription Service: GET 
  Subscription Service -->>- Subscribing PWA: 200 OK with Subscription Service Representation

    Note over Subscribing PWA, Authorization Server: Establish Subscription
  Subscribing PWA ->>+ Browser Messaging Service: Subscribe to Web Push Service
  Browser Messaging Service -->>- Subscribing PWA: Web Push Subscription data 

  Subscribing PWA ->>+ Subscription Service: Submit subscription to discovered subscription endpoint via POST
  Subscription Service ->>+ Authorization Server: Verify authorization
  Authorization Server -->>- Subscription Service: capabilities
  Subscription Service -->>- Subscribing PWA: 201 CREATED

  Note over Subscribing PWA, Authorization Server: Deliver Notifications for Subscription
  loop for each notification
    Subscription Service ->>+ Authorization Server: Verify authorization
    Authorization Server -->>- Subscription Service: capabilities
    Subscription Service -) Browser Messaging Service: Deliver notification
    Browser Messaging Service -) Subscribing PWA: Deliver notification
  end

  Note over Subscribing PWA, Authorization Server: Cancel Subscription
  Subscribing PWA ->>+ Browser Messaging Service: Unsubscribe (delete subscription)
  Subscribing PWA ->>+ Subscription Service: Unsubscribe (delete subscription)
  Subscription Service -->>- Subscribing PWA: 204 No Content