Mød Material-UI - dit nye foretrukne brugerinterfacebibliotek

Opdatering (17/05/2018): Material-UI v1.0.0 er ude! Tjek dette indlæg af Olivier.

Hvad? Endnu et bibliotek? Hvad er der galt med Bootstrap? Og hvorfor ikke v0.20?

Gode ​​spørgsmål! Lad os starte med en kort introduktion. I en nøddeskal er Material-UI et open source-projekt, der indeholder React-komponenter, der implementerer Googles Material Design.

Det startede i 2014, ikke længe efter at React kom ud til offentligheden, og er vokset i popularitet lige siden. Med over 35.000 stjerner på GitHub er Material-UI et af de bedste brugergrænsefladesbiblioteker til React derude.

Dens succes kom dog ikke uden udfordringer. Designet med LESS var Material-UI v0.x tilbøjelig til almindelige CSS-faldgruber, såsom globalt omfang, der fører projektet på CSS-in-JS-banen. Sådan nextskete det i 2016.

Rejsen mod bedre stil, som Olivier Tassinari udtrykker det, begyndte med inline-stilarter, men deres suboptimale ydeevne og begrænsede funktionsunderstøttelse (tænk pseudovælgere eller medieforespørgsler) gjorde i sidste ende holdets overgang til JSS. Og dreng gjorde de et smart valg.

Hvad er hype med v1-udgivelsen?

Det er dårligt. Det løser ikke kun de problemer, der er forbundet med MINDRE, men det låser også masser af fantastiske funktioner inklusiv

  • dynamiske stilarter genereret ved kørsel
  • indlejrede temaer med intuitive tilsidesættelser
  • reduceret belastningstid med kodedeling

Og mange flere. Biblioteket er også modent nok til at blive brugt i produktionen Så meget, at teamet foreslår v1 til alle nye projekter fremover.

Okay, skal vi bygge en app, eller hvad?

Glad for du spurgte! Til denne demo bygger vi en simpel fitnessapp. Alle er kede af at-gøre-apps nu, alligevel, ikke?

Læsning er fantastisk og alt sammen, men at se er ofte sjovere! Tjek denne playliste, jeg lavede på YouTube, hvis du vil opbygge en mere avanceret app.

Ok, du fik mig overbevist. Hvordan kommer jeg i gang?

Vi starter først vores app med create-react-app

create-react-app mui-fitnesscd mui-fitnesscode .

Og hvad med Material-UI?

Hvis du har garn, er installationen så enkel som

yarn add @material-ui/core

Ellers med npm

npm i @material-ui/core

For ikke længe siden ville vi specificere et @nexttag, der skal trækkes i den seneste præudgivelse (for eksempel kunne det have set ud v1.0.0-beta.47). Nu hvor både v1 og v0.x er under material-uirækkevidde, skal vi henvise til kernen i biblioteket for /coreat målrette mod den seneste udgivelse. Gå ikke glip af den sidste del, ellers ender du med den stabile 0.20afhængighed!

Vent, er det virkelig det?

Næsten! En sidste ting er skrifttyper. Vi følger den anbefalede Roboto-skrifttype fra Googles CDN:

Alternativt kan du trække det ind fra NPM med

yarn add typeface-roboto# or npm i typeface-roboto

i hvilket tilfælde skal du have en import ved roden af ​​dit projekt

// Make sure you only load 300, 400, & 500 font weights though!import 'typeface-roboto'

Færdig! Hvad gør jeg nu?

Lad os omlægge vores App.jskomponent, inden vi går videre

import React, { Component } from 'react'
export default class App extends Component { state = { exercises: [], title: '' }
 render() { return 

Exercises

}}

Og hvorfor ikke rydde op, index.jsmens vi er ved det?

import React from 'react'import { render } from 'react-dom'import App from './App'
render(, document.getElementById('root'))

Fjern gjerne de resterende filer under src, da vi ikke har brug for dem.

Hvor kommer Material-UI ind?

Fair nok, det er tid til at se det i aktion. Lad os ændre det grimme h1til en smuk Typographyoverskrift:

import Typography from '@material-ui/core/Typography'
...
 render() { return (  Exercises  ) }}
Bemærk, at siden v1.0.0-rc.0 flyttede MUI til, @material-ui/coreog importstien blev fladt. Dette var den sidste brudende ændring i præudgivelsen.

Så gå videre og løb for yarn startat se magien.

Vi er i gang med en god start! Typographykomponenten leveres med et foruddefineret sæt typestørrelser. Andre variants omfatter body1, title, display2, og så videre. Blandt andre indbyggede rekvisitter er, alignsom vi bruger her til at centrere teksten vandret, og gutterBottomsom tilføjer en bundmargen.

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? Buttons 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

  1. Prevent the default page reload
  2. Check if the title field is non-empty
  3. Set the state with an updater function to mitigate async updates
  4. Destructure exercises and title off the prevState object
  5. Spread out the exercises on the next state with a new exercise object
  6. 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.

Lad os prøve! I vores Appkomponent skal du oprette et typografiobjekt, ligesom du ville med inline-typografier. Derefter skal du komme med en nøgle, for eksempel rootmed henvisning til rodelementet Paper, og skrive nogle stilarter i camelCase

const styles = { root: { margin: 20, padding: 20, maxWidth: 400 }}

Importér derefter withStylesHOC framaterial-ui

import { withStyles } from '@material-ui/core/styles'

og pakk Appkomponenten med den, passerer stylesgenstand som arg

export default withStyles(styles)( class App extends Component { ... })
Bemærk, at du også kan bruge withStylesHOC som dekoratør. Husk, at create-react-react ikke understøtter dekoratører ud af kassen endnu, så hvis du insisterer på at bruge dem, skal du skubbe ud eller fork for at finjustere konfigurationen.

Dette vil injicere en classesprop, der Appindeholder et dynamisk genereret klassenavn til vores rootelement

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 le> tags. You could spot them if you dig int 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