intojs

const MVCComponent = () => {
  const [model, dispatch] = useReducer(reducer, initialModel);

  const handleEvent = () => {
    dispatch(action);
  };

  return <View model={model} handleEvent={handleEvent} />;
};

intojs

const withValidation = (state, field, value) => {
  const changedState = {
    ...state,
    fields: {
      ...state.fields,
      [field]: {
        ...state.fields[field],
        value,
      },
    },

intojs

const NewsletterForm = ({ newsletterOptions, onSubmit }) => {
  const [model, dispatch] = useReducer(reducer, initialModel);

  useEffect(() => {
    dispatch(actions.setNewsletterOptions(newsletterOptions));
  }, [newsletterOptions]);

  const handleFieldChange = (change) => {
    dispatch(actions.changeField(change));
  };

intojs

const isNewsletterFormModelValid = (model) => {
  const {
    fields: { fullName, newsletter },
  } = model;

  return !!(fullName.value && fullName.value.length > 2 && newsletter.value);
};

intojs

const setNewsletterOptions = (newsletterOptions) => ({
  type: actionTypes.SET_NEWSLETTERS_OPTIONS,
  payload: { newsletterOptions },
});

const changeField = (change) => ({
  type: actionTypes.CHANGE_FIELD,
  payload: change,
});

intojs

let counter = 0;

const count = () => {
  counter += 1;
}

intojs

const newsletterFormReducer = (state, action) => {
  const { type, payload } = action;

  switch (type) {
    case actionTypes.SET_NEWSLETTERS_OPTIONS:
      return {
        ...state,
        isLoading: payload.newsletterOptions.length === 0,
        fields: {
          ...state.fields,

intojs

const NewsletterFormView = (props) => {
  const classes = useStyles();

  const {
    model: {
      isLoading,
      isValid,
      fields: { newsletter },
    },
    onFieldChange,

intojs

const NewsletterFormModel = {
  isLoading: true,
  isValid: false,
  fields: {
    fullName: {
      value: "",
    },
    newsletter: {
      value: "",
      options: [],

intojs

class Controller {
  #model;

  initialize() {
    this.#model = new Model();

    const view = new View(this.#handleIncrementBtnClick);

    this.#model.attach(view);
  }