dceddia

render() {
  const { cameraPermission } = this.state;

  // Render one of 3 things depending on permissions
  return (
    <View style={styles.container}>
      {cameraPermission === null ? (
        <Text>Waiting for permission...</Text>
      ) : cameraPermission === false ? (
        <Text>Permission denied</Text>

dceddia

render() {
  const { photo } = this.state;

  return (
    <View style={{ flex: 1, width: '100%' }}>
     {photo ? (
       <ImageBackground
         style={{ flex: 1 }}
         source={{ uri: photo.uri }} />
     ) : (

dceddia

import React from 'react';
import { connect } from 'react-redux';

class Counter extends React.Component {
  increment = () => {
    this.props.dispatch({ type: 'INCREMENT' });
  }

  decrement = () => {
    this.props.dispatch({ type: 'DECREMENT' });

dceddia

function brokenReducer(state = initialState, action) {
  switch(action.type) {
    case 'INCREMENT':
      // NO! BAD: this is changing state!
      state.count++;
      return state;

    case 'DECREMENT':
      // NO! BAD: this is changing state too!
      state.count--;

dceddia

function reducer(state = initialState, action) {
  switch(action.type) {
    case 'INCREMENT':
      return {
        count: state.count + 1
      };
    case 'DECREMENT':
      return {
        count: state.count - 1
      };

dceddia

import React from 'react';

class Counter extends React.Component {
  increment = () => {
    // fill in later
  }

  decrement = () => {
    // fill in later
  }

dceddia

import React from 'react';
import { render } from 'react-dom';
import Counter from './Counter';

const App = () => (
  <div>
    <Counter />
  </div>
);

dceddia

import React from 'react';

class Counter extends React.Component {
  state = { count: 0 }

  increment = () => {
    this.setState({
      count: this.state.count + 1
    });
  }

dceddia

import React, { Component } from 'react';
import {
  BrowserRouter as Router,
  Route,
  Link
} from 'react-router-dom';
import './App.css';

class UsersView extends Component {
  state = {users: []}

dceddia

import React, { Component } from 'react';
import './App.css';

class App extends Component {
  state = {users: []}

  componentDidMount() {
    fetch('/users')
      .then(res => res.json())
      .then(users => this.setState({ users }));