Universal Model for Angular/React/Vue/Svelte

Universal model is a model which can be used with any combination of following UI frameworks:

• Angular 2+
• React 16.8+
• Svelte 3+
• Vue.js 3+

Install

npm install --save universal-model-ng-react-svelte-vue
 

Clean UI Architecture

• Model-View-Controller (https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller)
• User triggers actions by using view or controller
• Actions are part of model and they manipulate state that is stored
• Actions can use services to interact with external (backend) systems
• State changes trigger view updates
• Selectors select and calculate a transformed version of state that causes view updates
• Views contain NO business logic
• There can be multiple interchangeable views that use same part of model
• A new view can be created to represent model differently without any changes to model
• View technology can be changed without changes to the model

Clean UI Code directory layout

UI application is divided into UI components. Common UI components should be put into common directory. Each component can consist of subcomponents. Each component has a view and optionally controller and model. Model consists of actions, state and selectors. In large scale apps, model can contain sub-store. Application has one store which is composed of each components' state (or sub-stores)

- src
  |
  |- common
  |  |- component1
  |  |- component2
  |  . |- component2_1
  |  . 
  |  . 
  |  .
  |- componentA
  |- componentB
  |  |- componentB_1
  |  |- componentB_2
  |- componentC
  |  |- view
  |  .
  |  .
  |- componentN
  |  |- controller
  |  |- model
  |  |  |- actions
  |  |  |- services
  |  |  |- state
  |  |- view
  |- store
  

API

Common & Vue

createSubState(subState);
const store = createStore(initialState, combineSelectors(selectors));

const { componentAState } = store.getState();
const { selector1, selector2 } = store.getSelectors();
const [{ componentAState }, { selector1, selector2 }] = store.getStateAndSelectors();

Detailed Common & Vue API documentation

React

useStateReact([componentAState]);
useSelectorsReact([selector1, selector2]);
useStateAndSelectorsReact([componentAState], [selector1, selector2]);

Detailed React API documentation

Angular

useStateNg(this, { componentAState });
useSelectorsNg(this, { selector1, selector2 });
useStateAndSelectorsNg(this, { componentAState }, { selector1, selector2 });

Detailed Angular API documentation

Svelte

const [componentAState] = useStateSvelte(id, [state.componentAState]);
const [selector1, selector2] = useSelectorsSvelte(id, [selectors.selector1, selectors.selector2]);

Detailed Svelte API documentation

API Examples

Create initial states

const initialComponentAState = {
  prop1: 0,
  prop2: 0
};

Create selectors

When using foreign state inside selectors, prefer creating foreign state selectors and accessing foreign state through them instead of directly accessing foreign state inside selector. This will ensure better encapsulation of component state.

const createComponentASelectors = <T extends State>() => ({
  selector1: (state: State) => state.componentAState.prop1  + state.componentAState.prop2
  selector2: (state: State) => {
    const { componentBSelector1, componentBSelector2 } = createComponentBSelectors<State>();
    return state.componentAState.prop1 + componentBSelector1(state) + componentBSelector2(state);
  }
});

Create and export store in store.ts:

combineSelectors() checks if there are duplicate keys in selectors and will throw an error telling which key was duplicated. By using combineSelectors you can keep your selector names short and only namespace them if needed.

const initialState = {
  componentAState: createSubState(initialComponentAState),
  componentBState: createSubState(initialComponentBState)
};

export type State = typeof initialState;

const componentAStateSelectors = createComponentAStateSelectors<State>();
const componentBStateSelectors = createComponentBStateSelectors<State>();

const selectors = combineSelectors<State, typeof componentAStateSelectors, typeof componentBStateSelectors>(
  componentAStateSelectors,
  componentBStateSelectors
);

export default createStore<State, typeof selectors>(initialState, selectors);

in large projects you should have sub-stores for components and these sub-store are combined together to a single store in store.js:

componentBSubStore.js

export const initialComponentsBState = { 
  componentBState: createSubState(initialComponentBState),
  componentB_1State: createSubState(initialComponentB_1State),
  componentB_2State: createSubState(initialComponentB_2State),
};

const componentBStateSelectors = createComponentBStateSelectors<State>();
const componentB_1StateSelectors = createComponentB_1StateSelectors<State>();
const componentB_2StateSelectors = createComponentB_2Selectors<State>('componentB');

const componentsBStateSelectors = combineSelectors<State, typeof componentBStateSelectors, typeof componentB_1StateSelectors, typeof componentB_2StateSelectors>(
  componentBStateSelectors,
  componentB_1StateSelectors,
  componentB_2StateSelectors
);

store.js

const initialState = {
  ...initialComponentsAState,
  ...initialComponentsBState,
  .
  ...initialComponentsNState
};
      
export type State = typeof initialState;
    
const selectors = combineSelectors<State, typeof componentsAStateSelectors, typeof componentsBStateSelectors, ... typeof componentsNStateSelectors>(
  componentsAStateSelectors,
  componentsBStateSelectors,
  .
  componentsNStateSelectors
);
    
export default createStore<State, typeof selectors>(initialState, selectors);

Access store in Actions

Don't modify other component's state directly inside action, but instead call other component's action. This will ensure encapsulation of component's own state.

export default function changeComponentAAndBState(newAValue, newBValue) {
  const { componentAState } = store.getState();
  componentAState.prop1 = newAValue;
  
  // BAD
  const { componentBState } = store.getState();
  componentBState.prop1 = newBValue;
  
  // GOOD
  changeComponentBState(newBValue);
}

Vue views

Components should use only their own state and access other components' states using selectors provided by those components. This will ensure encapsulation of each component's state.

export default {
  setup(): object {
    const [ { componentAState }, { selector1, selector2 }] = store.getStateAndSelectors();
  
  return {
    componentAState,
    selector1,
    selector2,
    // Action
    changeComponentAState
  };
}

React views

Components should use only their own state and access other components' states using selectors provided by those components. This will ensure encapsulation of each component's state.

const View = () => {
  const [{ componentAState, { selector1, selector2 }] = store.getStateAndSelectors();
  useStateAndSelectorsReact([componentAState], [selector1, selector2]);
  
  // NOTE! Get the value of a selector using it's 'value' property!
  console.log(selector1.value);
}

Angular views

Components should use only their own state and access other components' states using selectors provided by those components. This will ensure encapsulation of each component's state.

export default class AComponent {
  state: typeof initialComponentAState;
  selector1: string,
  selector2: number
  // Action
  changeComponentAState = changeComponentAState
  
  constructor() {
    const [{ componentAState, { selector1, selector2 }] = store.getStateAndSelectors();
    useStateAndSelectors(this, { componentAState: state }, { selector1, selector2 });
  }
}

Svelte views

Components should use only their own state and access other components' states using selectors provided by those components. This will ensure encapsulation of each component's state.

<script>  
  const [componentAState] = useState('componentA', [store.getState().componentAState]);
  const selectors = store.getSelectors();
  const [selector1, selector2] = useSelectors('componentA', [selectors.selector1, selectors.selector2]);    
</script>

<div>
  {$componentAState.prop1}
  {$selector1} ...
<div>

Dependency injection

If you would like to use dependency injection (noicejs) in your app, check out this example, where DI is used to create services.

License

MIT License