React, Redux, ES2015 by Max Petruck

Why React?
Components
VirtualDOM
JSX

Components
Breaking UI into a compoent hierarchy is logical
They usually great at one thing
Components are highly reusable epecially in large apps
JSX is great for this

JSX JS
var HelloMessage = React.createClass({
render: function() {
return <div>Hello {this.props.name}</div>;
}
});
var HelloMessage = React.createClass({
displayName: "HelloMessage",
render: function render() {
return React.createElement(
"div",
null,
"Hello ",
this.props.name
);
}
});

VirtualDOM
E ciency
It has full event system
No direct DOM manipulations... Well you can manipulate DOM
directly if you want

What is Redux?
Is it Flux? Yes, and no
One store to rule them all.
Three principles of Redux make state mutations predictable and
reversable

Three principles of Redux
1. Single source of truth
2. State is read-only
3. Mutations are written as pure functions - reducers

Redux actions
{
type: MY_ACTION_TYPE,
// And here can be any data you need to transfer along with action
// If you need any
}

Reducers
Pure functions, that take action and state and return new state
State and Action ==> New State

Reducer composition
It helps to split data handling logic, when each of reducers is
managing its own part of the global state
Redux provides util combineReducers() that makes it easy to use.

Store
Holds application state
Allows access to state
Allows state to be updated

Data Flow
1. You call store.dispatch(action)
2. Redux store calls the root reducer
3. The Redux store saves state returned by the root reducer.

Middleware
It provides a third-party extension point between dispatching an
action, and the moment it reaches the reducer.

Modules
Static module structure
Helps avoid global variables
Support for cyclic dependencies between modules

Lambda functions
New function creation syntax
Lexical binding
Has no 'arguments'

Examples
function () { return 1; }
() => { return 1; }
() => 1
function (a) { return a * 2; }
(a) => { return a * 2; }
(a) => a * 2
a => a * 2
function (a, b) { return a * b; }
(a, b) => { return a * b; }
(a, b) => a * b
function () { return arguments[0]; }
(...args) => args[0] // ES6 rest syntax helps to work without 'arguments'
() => {} // undefined
() => ({}) // {}

Spread operator
Math.max(-1, 5, 11, 3) // 11
Math.max(...[-1, 5, 11, 3]) // 11
Math.max(-1, ...[5, 11], 3) // 11
// example from Tic Tac Toe React
// with ES6 spread operator
function getMaxElement(arr) {
return Math.max(...arr);
}
// without ES6 spread
function getMaxElement(arr) {
return Math.max.apply(null, arr);
}

Rest operator
function f(x, ...y) {
···
}
f('a', 'b', 'c'); // x = 'a'; y = ['b', 'c']
f(); // x = undefined; y = []

Destructuring
// Can work with objects
let {one, two} = {one: 1, two: 2} // one = 1, two = 2
// And arrays
let [,,x] = ['a', 'b', 'c', 'd']; // x = 'c'
// Is that it? Nope, array destructuring works with iterable objects
// Like strings
let [x,y] = 'abc'; // x='a'; y=['b', 'c']
// And Set
let [x, y] = new Set(['x', 'y']); // x = 'x', y = 'y'
// and etc.
// It's works great with rest operator
let [x,...y] = 'abc'; // x='a'; y=['b', 'c']
// And looks great in functions
function ([x, y, ...rest]) {...}

let, const
let and const are block scoped
let and const don't get hoisted have TDZ (Temporal Dead Zone)
Variables de ned with let/const can't be de ned more than once
in the same scope

Template strings
// Can contain multiline strings
let multiline = `line 1
line2`; // and spaces matter
let x = 1;
// Can evaluate variables, or expressions inside ${...}
let str = `${x + 41}` // str = '42'
// Can be tagged
function firstString(stringsArray, ...allValues) { // using the new ES6 rest syntax
// allValues is array of values passed inside ${}
return stringsArray[0];
}
let firstStr = firstString `Some text ${x} bla-bla`;
// firstStr = 'Some text ';

Async stuff
Promises
Generators
ES7 Proposals

The End
Useful links:
-
-
-
-
Why React?
Flux overview
Redux documentation
ES6 Overview
My email: maxim.petruck@lingvokot.com
Our organization on Github: github.com/Lingvokot

React, Redux, ES2015 by Max Petruck

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

Similaire à React, Redux, ES2015 by Max Petruck

Similaire à React, Redux, ES2015 by Max Petruck (20)

Dernier

Dernier (20)

React, Redux, ES2015 by Max Petruck