
Mi? Még egy könyvtár? Mi a baj a Bootstrap-tal? És miért ne v0.20?
Remek kérdések! Kezdjük egy rövid bevezetéssel. Dióhéjban az Material-UI egy nyílt forráskódú projekt, amely a Google Material Design-ját megvalósító React komponenseket tartalmazza.
2014-ben indult, nem sokkal azután, hogy a React megjelent a nyilvánosság előtt, és azóta egyre népszerűbb. A GitHub több mint 35 000 csillagjával az Material-UI az egyik legnépszerűbb felhasználói felület könyvtár a React számára.
Ennek ellenére sikere nem járt kihívások nélkül. A LESS használatával tervezett Material-UI v0.x hajlamos volt a közös CSS buktatókra, például a globális hatókörre, amelyek a CSS-in-JS pályán vezetik a projektet. Így next
alakult 2016-ban.
Az út a jobb stílus felé, ahogy Olivier Tassinari megfogalmazta, a belső stílusokkal kezdődött, de azok nem optimális teljesítménye és korlátozott funkciótámogatásuk (gondolom, hogy álválasztók vagy médiakérdések) végső soron átállták a csapatot a JSS-re. És fiú okosan választottak-e.
Mi a hype a v1 kiadással?
Rossz szamár. Nemcsak a LESS problémáival foglalkozik, hanem rengeteg fantasztikus funkciót is felold
- futás közben generált dinamikus stílusok
- beágyazott témák intuitív felülírással
- csökkentett betöltési idő a kód felosztásával
És még sok más. A könyvtár is elég kiforrott ahhoz, hogy a termelésben felhasználható legyen, olyannyira, hogy a csapat javasolja a v1 verziót minden új projektre.
Rendben, építünk egy alkalmazást, vagy mi?
Örülök, hogy megkérdezte! Ehhez a bemutatóhoz elkészítünk egy egyszerű fitnesz alkalmazást. Amúgy mindenki unja a tennivaló alkalmazásokat, igaz?
Az olvasás nagyszerű és minden, de a nézés sokszor szórakoztatóbb! Nézze meg ezt a lejátszási listát, amelyet a YouTube-on készítettem, ha fejlettebb alkalmazást szeretne létrehozni.
Ok, meggyőztél. Hogyan kezdjem?
Először elindítjuk az alkalmazásunkat a create-reagál-alkalmazással
create-react-app mui-fitnesscd mui-fitnesscode .
És mi van a Material-UI-val?
Ha van fonal, akkor a telepítés olyan egyszerű, mint a
yarn add @material-ui/core
Egyébként azzal npm
npm i @material-ui/core
Nem is olyan régen megadtuk a @next
címkét, amely behúzza a legújabb előzetes kiadást (például úgy nézhetett ki v1.0.0-beta.47
). Most, hogy a v1 és a v0.x egyaránt material-ui
hatókör alá tartozik, /core
a legfrissebb kiadás megcélzása érdekében hivatkoznunk kell a könyvtár magjára . Ne hagyja ki ezt az utolsó részt, különben a stabil 0.20
függőség lesz a vége !
Várj, tényleg így van?
Majdnem! Utolsó dolog a betűtípusok. Megyünk a Google CDN-jének ajánlott Roboto betűtípusával:
Alternatív megoldásként az NPM-mel behúzhatja
yarn add typeface-roboto# or npm i typeface-roboto
ebben az esetben a projekt gyökeréhez importálásra van szükség
// Make sure you only load 300, 400, & 500 font weights though!import 'typeface-roboto'
Kész! Mit tegyek ezután?
Nos, tegyük át az App.js
alkatrészünket, mielőtt tovább mennénk
import React, { Component } from 'react'
export default class App extends Component { state = { exercises: [], title: '' }
render() { return Exercises
}}
És miért ne takarítanánk, index.js
amíg ott vagyunk?
import React from 'react'import { render } from 'react-dom'import App from './App'
render(, document.getElementById('root'))
Távolítsa el src
nyugodtan a fennmaradó fájlokat az alól , mivel nincs szükségünk rájuk.
Hol jön be az Material-UI?
Elég tisztességes, itt az ideje, hogy működés közben lássuk. Változtassuk a csúnyát h1
gyönyörű Typography
fejlécre:
import Typography from '@material-ui/core/Typography'
...
render() { return ( Exercises ) }}
Ne feledje, hogy a v1.0.0-rc.0 óta az MUI átment a (z) helyre,
@material-ui/core
és az import elérési útja ellapult. Ez volt az utolsó áttörő változás az előzetes kiadásban.
Ezután menj előre, és szaladj, yarn start
hogy megnézhesd a varázslatot.

Jól indulunk! Typography
komponens előre definiált típusmérettel rendelkezik. Egyéb variant
ok közé body1
, title
, display2
és így tovább. A többi beépített kellék között megtalálhatjuk align
a szöveg vízszintes középre állítását, és gutterBottom
ez alsó margót ad hozzá.
Why don’t we expand this to a form, so we can create our own exercises? We’ll start with a TextField
and bind it to the title
on the state
import Typography from '@material-ui/core/Typography'import TextField from '@material-ui/core/TextField'
...
handleChange = ({ target: { name, value } }) => this.setState({ [name]: value })
render() { const { title } = this.state return ( ... ) }}
Of course, we’d need to make React happy by wrapping Typography
and form
with a parent element. What could be a better opportunity for a paper-sheet card-like background? Let’s reach out to Paper
then
import Paper from '@material-ui/core/Paper'
...
render() { const { title } = this.state return ... } }}
It’s also about time to start using named imports (assuming our Webpack setup allows for tree shaking):
import { Paper, Typography, TextField } from '@material-ui/core'
Sweet! And what good is a form without the submit button? Button
s are a staple component in Material-UI; you’ll see them everywhere. For instance,
import { Paper, Typography, TextField, Button } from '@material-ui/core'... Create }}
It should read well. type
is a regular React prop, color
and variant
are Material-UI-specific, and make up a rectangle-shaped button. Another variant would be fab
for a floating button, for example.

It doesn’t do much though. We’ll have to intercept the form submit event
return ... ... }}
and then handle it with
handleCreate = e => { e.preventDefault()
if (this.state.title) { this.setState(({ exercises, title }) => ({ exercises: [ ...exercises, { title, id: Date.now() } ], title: '' })) } }
Whoa! What’s that cryptic code all about? Very quickly, we
- Prevent the default page reload
- Check if the
title
field is non-empty - Set the state with an updater function to mitigate async updates
- Destructure
exercises
andtitle
off theprevState
object - Spread out the
exercises
on the next state with a new exercise object - Reset the
title
to clear out the input field
Guess I should have mentioned that I’m in love with ES6 too. Aren’t we all?
But how do we list them?
Now is the right time to. Is there a list component? Of course, you silly goose!
Inside a List
, we’ll loop through our exercises
and return a ListItem
with some ListItemText
for each
import { List, ListItem, ListItemText } from '@material-ui/core'
...
render() { const { title, exercises } = this.state return ... {exercises.map(({ id, title }) => )} }}
Let’s also hard-code a few initial exercises to get something on the screen. You guessed it, the trinity of all weight lifting workouts, ladies and gents:
state = { exercises: [ { id: 1, title: 'Bench Press' }, { id: 2, title: 'Deadlift' }, { id: 3, title: 'Squats' } ], title: '' }

Last but not least, our users are likely to make typos, so we better add a delete button next to each exercise, so they could remove entries they no longer want in their list.
We can use ListItemSecondaryAction
to do exactly that. Placed on the far right of the list item, it can hold a secondary control element, such as an IconButton
with some action
import { /*...*/, ListItemSecondaryAction, IconButton} from '@material-ui/core'
...
this.handleDelete(id)} > {/* ??? */}
...
And let’s not forget the delete handler as well:
handleDelete = id => this.setState(({ exercises }) => ({ exercises: exercises.filter(ex => ex.id !== id) }))
which will simply filter our exercises down to those that don’t match the id
of the one that needs to be removed.
Can we have a trash bin icon inside the button?
Yes, that would be great! Though you could use Material Icons from Google’s CDN directly with either Icon
or SvgIcon
components, it’s often preferable to go with a ready-made preset.
Luckily, there’s a Material-UI package for those
yarn add @material-ui/icons# or npm i @material-ui/icons
It exports 900+ official material icons as React components, and the icon names are nearly identical, as you’ll see below.
Let’s say we wanted to add a trash icon. We’d first head over to material.io/icons to find out its precise name

Then, we turn that name into PascalCase in our import path
import Delete from '@material-ui/icons/Delete'
Just like with Material-UI components, if your setup has tree-shaking enabled, you could shorten the import to
import { Delete } from '@material-ui/icons'
which is especially useful when importing several icons at once.
Now that we have our trash icon, let’s display it inside our delete button
this.handleDelete(id)}>

How can I make the form look less ugly?
Ah, styling. I thought you’d never ask! A gentle touch of CSS wouldn’t hurt. So then, do we import an external stylesheet with global styles? Or, perhaps, use CSS modules and assign scoped class names to our elements? Not quite.
Under the hood, Material-UI forks a CSS-in-JS library known as react-jss.
It’s a React integration of the JSS library by the same author, Oleg Isonen. Remember we touched on it in the beginning? Its basic idea is to enable you to define styles in JavaScript. What makes JSS stand out among other libs though, is its support for SSR, small bundle size, and rich plugin support.
Próbáljuk meg! A mi App
összetevő, hozzon létre egy stílust kifogást, mint akkor inline stílus. Ezután álljon elő egy kulccsal, például root
a gyökérelemre hivatkozva Paper
, és írjon ki néhány stílust a camelCase-ben
const styles = { root: { margin: 20, padding: 20, maxWidth: 400 }}
Ezután importálja a withStyles
HOC-t innenmaterial-ui
import { withStyles } from '@material-ui/core/styles'
és tekerje be vele a App
komponenst, az styles
objektumot argként továbbítva
export default withStyles(styles)( class App extends Component { ... })
Ne feledje, hogy withStyles
dekorációként HOC-t is használhat
. Ne feledje, hogy a create-reagál-reakció még nem támogatja a díszítőket a dobozon kívül, így ha ragaszkodik hozzájuk, akkor ki kell dobnia vagy el kell villáznia a konfiguráció módosítását.
Ez adja a classes
prop be App
, amely egy dinamikusan generált osztály nevét a mi root
elem

The class name is guaranteed to be unique, and it will often be shortened in a production build. We then assign it to Paper
via className
attribute
render() { const { title, exercises } = this.state const { classes } = this.props
return ... }

How does this magic work? Turns out, withStyles
is responsible for the dirty work. Behind the scenes, it injected an array of styles into the DOM under
o the
with dev tools

You could also see other style
tags related to native components, such as MuiListItem
for the ListItem
component we imported earlier. Those are auto-injected on demand, for each given UI element that you import.
That means that Material-UI will never load any styles for the components that we don’t use. Hence, increased performance and faster load times. This is very different from Bootstrap, which requires loading the entire monolithic CSS bundle, whether you happen to use its vast assortment of classes or not.
Let’s also style the form so it looks neat
const styles = { root: { ... }, form: { display: 'flex', alignItems: 'baseline', justifyContent: 'space-evenly' }}
This will make the text field and the button nicely spaced out. Feel free to refer to align-items and justify-content at CSS-Tricks should you need any further clarification on the Flexbox layout.

Sure, but what’s up with theming then?
withStyles
HOC is tailored for customizing a one-off component, but it’s not suited for application-wide overwrites. Whenever you need to apply global changes to all components in Material-UI, your first instinct would be to reach out to the theme
object.
Themes are designed to control colors, spacing, shadows, and other style attributes of your UI elements. Material-UI comes with built-in light and dark theme types, light being the default.
If we turn our styles
into an anonymous function, it will receive the theme
object as an arg, so we can inspect it
const styles = theme => console.log(theme) || ({ root: ..., form: ...})

The way you customize your theme is through configuration variables, like palette
, type
, typography
, etc. To have a closer look at all the nested properties and options, visit the Default Theme section of the Material-UI docs.
Let’s say we wanted to change the primary color from blue
to orange
. First off, we need to create a theme with createMuiTheme
helper in index.js
import { createMuiTheme } from '@material-ui/core/styles'
const theme = createMuiTheme({ /* config */ })
In Material-UI, colors are defined under the palette
property of theme
. The color palette is subdivided into intentions which include primary
, secondary
, and error
. To customize an intention, you can simply provide a color object
import { orange } from '@material-ui/core/colors'
const theme = createMuiTheme({ palette: { primary: orange }})
When applied, the color will then be calculated for light
, main
, dark
, and contrastText
variations. For more granular control though, you could pass in a plain object with any of those four keys
const theme = createMuiTheme({ palette: { primary: { light: orange[200] // same as '#FFCC80', main: '#FB8C00', // same as orange[600] dark: '#EF6C00', contrastText: 'rgb(0,0,0)' } }})
As you can see, individual colors can be expressed as both a hex or rgba string (#FFCC80
) and a hue/shade pair (orange[200]
).

Creating a theme on its own won’t suffice. To overwrite the default theme, we would need to position MuiThemeProvider
at the root of our app and pass our custom theme
as a prop
import { /*...*/, MuiThemeProvider } from '@material-ui/core/styles'
const theme = createMuiTheme({ palette: { primary: orange }})
render( , document.getElementById('root'))
MuiThemeProvider
will then pass down the theme
to all its child elements through React context.

Though it may seem like a lot of work to change a color, keep in mind that this overwrite will propagate to all components nested under the provider. And apart from colors, we can now fine-tune viewport sizes, spacing, opacity, and many other parameters.
Utilizing config variables when styling your components will aid with consistency and symmetry in your app’s UI. For example, instead of hard-coding magic values for margin
and padding
on our Paper
component, we could instead rely on the spacing unit off the theme
const styles = ({ spacing: { unit } }) => ({ root: { margin: unit, padding: unit * 3, maxWidth: 400 }, form: ...}
theme.spacing.unit
comes at 8px
by default, but if it’s used uniformly across the app, when we need to update its value, rather than scavenging across the entire codebase, we only need to change it in one place, that is, in our options object that we pass to createMuiTheme
.
Theme variables are plentiful, and if you run into a use case that’s not covered by the built-in theme object, you could always define your own custom vars. Here’s a slightly modified version of our fitness app that showcases color palette, theme type, and spacing unit options

Note that the example above is only a demo. It re-creates a new theme each time an option changes, which leads to a new CSS object being re-computed and re-injected into the DOM. Most often than not, your theme config will remain static.
There are far more interesting features that we haven’t covered. For example, Material-UI comes with an opt-in CssBaseline
component that applies cross-browser normalizations, such as resetting margins or font family (very much like normalize.css does).
As far as components go, we have our standard Grid
with a 12-column layout and five viewports (xs
, sm
, md
, lg
, and xl
). We’ve also got familiar components like Dialog
, Menu
, and Tabs
, as well as elements, such as Chip
and Tooltip
. Indeed, there’s a whole slue of others, and fortunately, they are all very-well documented with runnable demo code from CodeSandbox

Aside from that, Material-UI Next also works with SSR, if you’re into that. Besides, although it comes with JSS out of the box, it can me made to work with just about any other library, like Styled Components, or even raw CSS.
Be sure to check out the official docs for more info.
I hope you found this read useful! And if you like it so much that you are excited to learn more about Material-UI or React, then check out my YouTube channel maybe?
Thanks for stopping by! And big thanks to the team over at Call-Em-All and all the backers who helped to build this awesome library ❤️
Cheers,
Alex