The Basics
The @dnb/eufemia
is hosted on the global NPM registry. It includes all the necessary parts to build an independent layer on top of a frontend framework of your choice.
It is recommended to have an application setup with a compiling/build process in place.
HTML Elements and styling
There are three things going on once an HTML element is displayed and up-and-running:
- Syntax as HTML
- Styling by CSS
- Internal states by JavaScript
From here we can redefine the properties of the HTML elements in order to customize them. We can also bind event listeners to work together with your application.
Pixel Perfect
One of the most important reasons why Eufemia exists, is to make it easier to get a pixel perfect result when developing WEB Applications.
You will have come a long way to achieve this by using @dnb/eufemia
correctly:
- Make sure you import the style packages correctly (with or without CSS reset depending on your legacy code situation)
- Always (mostly) use
rem
to the nearest "8px" value, like 1px = 0.0625rem (1/16) - Always use the HTML Elements or UI Components
- Follow these useful tips on styling
Make sure you test your layout and styles for various conditions during and after development:
- Up two 3x times in font-size (change the Web Browser default font size)
- Zoom the Web Browser up to 3x times
- Make your layout responsive, either with CSS Grid or Media Queries
- Check the different screen sizes
- Test your app on different devices and operating systems
- Pixel perfection is good for many, for the rest, make everything accessible for everyone
States
All the UI Components (and some HTML Elements) have individual interaction states. The look and feel is defined in the default theming file (theme-ui).
- hover
- active (TouchStart)
- focus
- disabled
CSS Styles
Read about how the styles are setup and how to import the CSS.
Compiler
With Node.js as our JavaScript runtime in place, we may use ES6 (ECMAScript 2015) to write our application. There are many frameworks and libraries to build user interfaces. If we take React JSX as an starting point, we basically do this:
// Define the importsimport { Button } from '@dnb/eufemia'// And consume the Component in your markup render methodrender(<Button text="Primary Button" />)
You also may import the styles on a higher level in your application:
// e.g. in the App rootimport '@dnb/eufemia/style'
You can also import a single style of one component at a time:
// Imports only the Button CSS and Main DNB Themeimport '@dnb/eufemia/components/button/style'import '@dnb/eufemia/components/button/style/themes/ui'
<Button text="Button" on_click={myClickHandler} />
Importing components and elements
By default, you can import components
and elements
from the root:
import { Button } from '@dnb/eufemia'
As the @dnb/eufemia
uses ESM as its default module format, we get a good tree shaking with most of the bundler tools commonly used.
But you can be more specific if you want to:
import { Button } from '@dnb/eufemia/components'import { Anchor } from '@dnb/eufemia/elements'
And even go further:
import Button from '@dnb/eufemia/components/Button'// orimport Button from '@dnb/eufemia/components/button/Button'
Importing extensions
Extensions you would have to import explicitly from /extensions
import { ... } from '@dnb/eufemia/extensions'
Importing icons
The same applies to icons, you would have to import them explicitly from /icons
import { bell_medium as Bell } from '@dnb/eufemia/icons'// orimport Bell from '@dnb/eufemia/icons/bell'import BellMedium from '@dnb/eufemia/icons/bell_medium'
UMD
In case you don't have a compiling/build process, you can use the UMD packed version of the @dnb/eufemia
. Take a look into this repo and the UMD example usage. But this will not optimize your code for the best user experience.
<html><head>...<linkrel="stylesheet"href="https://unpkg.com/@dnb/eufemia@latest/style/dnb-ui-core.min.css"/><linkrel="stylesheet"href="https://unpkg.com/@dnb/eufemia@latest/style/themes/theme-ui/dnb-theme-components.min.css"/><linkrel="stylesheet"href="https://unpkg.com/@dnb/eufemia@latest/style/themes/theme-ui/dnb-theme-basis.min.css"/></head><body>...<script src="https://unpkg.com/@dnb/eufemia@latest/umd/dnb-ui-icons.min.js"></script><script src="https://unpkg.com/@dnb/eufemia@latest/umd/dnb-ui-lib.min.js"></script></body></html>