JBreit/actions.ts

## actions.ts
export const ADD_TODO = '[Todo] Add Todo';
export const REMOVE_TODO = '[Todo] Remove Todo';

export class AddTodo {
  readonly type = ADD_TODO;
  constructor(private payload: any) {}
}

export class RemoveTodo {
  readonly type = REMOVE_TODO;
  constructor(private payload: any) {}
}

## app.ts
import * as fromStore from './store';
import { renderTodos } from './utils';

const input = document.querySelector('input') as HTMLInputElement;
const button = document.querySelector('button') as HTMLButtonElement;
const destroy = document.querySelector('.unsubscribe') as HTMLButtonElement;
const todoList = document.querySelector('.todos') as HTMLLIElement;

const reducers = {
  todos: fromStore.reducer,
};

const store = new fromStore.Store(reducers);

button.addEventListener('click', () => {
  if (!input.value.trim()) return;

  const todo = { label: input.value, complete: false };

  store.dispatch(new fromStore.AddTodo(todo));

  input.value = '';
}, false);

const unsubscribe = store.subscribe((state: any) => {
  renderTodos(state.todos.data);
});

destroy.addEventListener('click', unsubscribe, false);

todoList.addEventListener('click', function (event) {
  const target = event.target as HTMLButtonElement;

  if (target.nodeName.toLowerCase() === 'button') {
    const todo = JSON.parse(target.getAttribute('data-todo') as any);

    store.dispatch(new fromStore.RemoveTodo(todo));
  }
});

store.subscribe((state: any) => console.log('STATE:::', state));

## index.html
<!DOCTYPE html>
<html lang="en">
  <head>
    <base href="/">
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">

    <title>TypeScript Greeter</title>
  </head>
  <body>
    <div id="app-root" role="app">
      <p>You have <span></span> todos.</p>
      <input type="text">
      <button type="button" class="addTodo">Add todo</button>
      <ul class="todos"></ul>
      <button type="button" class="unsubscribe">Unsubscribe</button>
    </div>
    <script src="app.js"></script>
  </body>
</html>

## reducers.ts
import * as fromActions from './actions';

export const initialState = {
  loaded: false,
  loading: false,
  data: [{ label: 'Test Todo Application', complete: false }],
};

export function reducer(state = initialState, action: { type: string, payload: any }) {
  switch (action.type) {
    case fromActions.ADD_TODO: {
      const todo = action.payload;
      const data = [...state.data, todo];

      return {
        ...state,
        data,
      };
    }

    case fromActions.REMOVE_TODO: {
      const data = state.data.filter(todo => todo.label !== action.payload.label);

      return {
        ...state,
        data,
      };
    }
  }
  return state;
}

## store.ts
export class Store {
  private subscribers: Function[];
  private reducers: { [key: string]: Function };
  private state: { [key: string]: any };

  constructor(reducers = {}, initialState = {}) {
    this.subscribers = [];
    this.reducers = reducers;
    this.state = this.reduce(initialState, {});
  }

  get value() {
    return this.state;
  }

  subscribe(fn: any) {
    this.subscribers = [...this.subscribers, fn];
    this.notify();

    return () => {
      this.subscribers = this.subscribers.filter(sub => sub !== fn);
    };
  }

  dispatch(action: any) {
    console.log(action);
    this.state = this.reduce(this.state, action);
    this.notify();

    console.log(this.state);
  }

  private notify() {
    this.subscribers.forEach(fn => fn(this.value));
  }

  private reduce(state: any, action: any) {
    const newState: any = {};

    for (const prop in this.reducers) {
      newState[prop] = this.reducers[prop](state[prop], action);
    }
    return newState;
  }
};

## utils.ts
const span = document.querySelector('span') as HTMLSpanElement;
const todoList = document.querySelector('.todos') as HTMLLIElement;

export function renderTodos(collection: any) {
  if (span && todoList) {
    span.innerHTML = collection.length;
    todoList.innerHTML = '';

  for (const item of collection) {
      todoList.innerHTML = `
        <li>
          ${item.label}
          <button type="button" data-todo='${JSON.stringify(item)}'>
            Delete
          </button>
        </li>
      `;
    }
  }

}
	export const ADD_TODO = '[Todo] Add Todo';
	export const REMOVE_TODO = '[Todo] Remove Todo';

	export class AddTodo {
	readonly type = ADD_TODO;
	constructor(private payload: any) {}
	}

	export class RemoveTodo {
	readonly type = REMOVE_TODO;
	constructor(private payload: any) {}
	}
	import * as fromStore from './store';
	import { renderTodos } from './utils';

	const input = document.querySelector('input') as HTMLInputElement;
	const button = document.querySelector('button') as HTMLButtonElement;
	const destroy = document.querySelector('.unsubscribe') as HTMLButtonElement;
	const todoList = document.querySelector('.todos') as HTMLLIElement;

	const reducers = {
	todos: fromStore.reducer,
	};

	const store = new fromStore.Store(reducers);

	button.addEventListener('click', () => {
	if (!input.value.trim()) return;

	const todo = { label: input.value, complete: false };

	store.dispatch(new fromStore.AddTodo(todo));

	input.value = '';
	}, false);

	const unsubscribe = store.subscribe((state: any) => {
	renderTodos(state.todos.data);
	});

	destroy.addEventListener('click', unsubscribe, false);

	todoList.addEventListener('click', function (event) {
	const target = event.target as HTMLButtonElement;

	if (target.nodeName.toLowerCase() === 'button') {
	const todo = JSON.parse(target.getAttribute('data-todo') as any);

	store.dispatch(new fromStore.RemoveTodo(todo));
	}
	});

	store.subscribe((state: any) => console.log('STATE:::', state));
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<base href="/">
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1">

	<title>TypeScript Greeter</title>
	</head>
	<body>
	<div id="app-root" role="app">
	<p>You have <span></span> todos.</p>
	<input type="text">
	<button type="button" class="addTodo">Add todo</button>
	<ul class="todos"></ul>
	<button type="button" class="unsubscribe">Unsubscribe</button>
	</div>
	<script src="app.js"></script>
	</body>
	</html>
	import * as fromActions from './actions';

	export const initialState = {
	loaded: false,
	loading: false,
	data: [{ label: 'Test Todo Application', complete: false }],
	};

	export function reducer(state = initialState, action: { type: string, payload: any }) {
	switch (action.type) {
	case fromActions.ADD_TODO: {
	const todo = action.payload;
	const data = [...state.data, todo];

	return {
	...state,
	data,
	};
	}

	case fromActions.REMOVE_TODO: {
	const data = state.data.filter(todo => todo.label !== action.payload.label);

	return {
	...state,
	data,
	};
	}
	}
	return state;
	}
	export class Store {
	private subscribers: Function[];
	private reducers: { [key: string]: Function };
	private state: { [key: string]: any };

	constructor(reducers = {}, initialState = {}) {
	this.subscribers = [];
	this.reducers = reducers;
	this.state = this.reduce(initialState, {});
	}

	get value() {
	return this.state;
	}

	subscribe(fn: any) {
	this.subscribers = [...this.subscribers, fn];
	this.notify();

	return () => {
	this.subscribers = this.subscribers.filter(sub => sub !== fn);
	};
	}

	dispatch(action: any) {
	console.log(action);
	this.state = this.reduce(this.state, action);
	this.notify();

	console.log(this.state);
	}

	private notify() {
	this.subscribers.forEach(fn => fn(this.value));
	}

	private reduce(state: any, action: any) {
	const newState: any = {};

	for (const prop in this.reducers) {
	newState[prop] = this.reducers[prop](state[prop], action);
	}
	return newState;
	}
	};
	const span = document.querySelector('span') as HTMLSpanElement;
	const todoList = document.querySelector('.todos') as HTMLLIElement;

	export function renderTodos(collection: any) {
	if (span && todoList) {
	span.innerHTML = collection.length;
	todoList.innerHTML = '';

	for (const item of collection) {
	todoList.innerHTML = `
	<li>
	${item.label}
	<button type="button" data-todo='${JSON.stringify(item)}'>
	Delete
	</button>
	</li>
	`;
	}
	}

	}