Model

Model is an abstract utility class that provides an easy way to observe specific properties of an object.

• Reference
  • use()
• Usage
  • Observing properties

Reference

use()

The use method is used to observe the properties of a model. It's intended to be used only in hooks.

Returns

An object containing all of the model's observable properties.

Usage

Observing properties

Since Model is an abstract class, you'll need to extend it to use it. Let's say you have an app state that looks like this:

class AppState {
  public user = new Observable<User>();
  public isLoggedIn = new Observable<boolean>();
}

You can use Model to observe the properties of AppState like this:

import { injectHook, Model } from 'react-obsidian';

// 1. Make AppState extend Model
class AppState extends Model {
  public user = new Observable<User>(); // { firstName: string; lastName: string;}
  public isLoggedIn = new Observable<boolean>();
}

// 2. `appState` is injected into the hook
const _useUserName = (appState: AppState) => {
  // 3. Use `appState.use()` to observe the properties
  const {user, isLoggedIn} = user.use();

  return `${user.firstName} is ${isLoggedIn ? '' : 'not '}logged in`;
};

export const useUserName = injectHook(_useUserName, /* SomeGraph */);