PubSub.md

Explanation

• The code defines a StoreProvider component that is intended to be used as a top-level component in a React application to manage the global state.
• The component uses the React Hooks useState to initialize the state with the initialData prop passed in and to manage updates to the state using the dispatch method.
• The component also defines three methods for working with a pub-sub pattern: publish, subscribe, and unsubscribe.

• publish(topic: string, args: any) : this method will take in a topic and data, it will log the topic with the data being published and it will search for the subscribers of the topic if any, and call the callback for all the subscribers

• subscribe(topic: string, func: (topic: string, data: any) => void) : this method will take in a topic and callback function, it will log the topic the client has subscribed to and it will save the topic and the callback along with unique token to know which subscription is which and which subscription to unsubscribe later.

• unsubscribe(token: string): This method will take in a token, it will search all the topics and their subscribers and if it finds the token of the subscription, it will remove the subscription from the list of subscribers, log the topic unsubscribed from.

The component uses React context to make the state, dispatch, subscribe, unsubscribe, publish methods available to all child components.

UML Diagram for State Sore

classDiagram
class StoreProvider {
  +state: any
  +dispatch(action: Action): void
  +subscribe(topic: string, func: (topic: string, data: any) => void): string
  +unsubscribe(token: string): void
  +publish(topic: string, args: any): void
}

class Topic {
  +token: string
  +func: (topic: string, data: any) => void
}

StoreProvider --> state
StoreProvider --> dispatch
StoreProvider --> subscribe
StoreProvider --> unsubscribe
StoreProvider --> publish

StoreProvider --> Topic
Topic --> token
Topic --> func