Description
The Theme component is a helper component that lets you create nested theming solutions.
<Theme>
will by default create a div
wrapper, when no custom element is defined (e.g. element="span"
).
import { Theme, useTheme } from '@dnb/eufemia/shared'const Component = () => {const { name, propMapping } = useTheme()return 'My Component'}render(<Theme name="theme-name"><App><Theme propMapping="my-class"><MyComponent /></Theme></App></Theme>,)
Will create the following HTML/CSS classes:
Outer Theme
eufemia-theme__theme-name
Nested Theme
eufemia-theme__theme-name
eufemia-theme__prop-mapping--my-class
With that, you can create your own styles that contains the wanted style mapping.
propMapping
Mapping of properties with WIP: This API may change in future, as it is currently under development. Please get in touch with us before you use it.
In order to change or map CSS properties, you can make use of the propMapping
solution.
The main motivation of this feature is to provide a set of maps you can use in your app. But it lets you create your own sets as well. To do so;
- Define an area in your app – it could be your component – and give it a declarative name:
import { Theme } from '@dnb/eufemia/shared'render(<Theme propMapping="my-maps"><MyComponent /></Theme>,)
- Define the needed CSS properties:
.eufemia-theme__theme-name.eufemia-theme__prop-mapping--my-maps {--color-sea-green: var(--sb-color-purple-alternative);}
Use your component as the wrapper element
You can provide your component as the wrapper. This way no additional HTML Element will be created.
import { Theme } from '@dnb/eufemia/shared'const Component = ({ classNamem ...props }) => {return <div className={classNamem+' more-classes'}></div>}render(<Theme name="theme-name"><App><Theme propMapping="my-maps" element={Component}>...</Theme></App></Theme>)
Hide or show parts of your component (filter)
With this helper function you show or hide content based on inherited theme properties.
import { Theme, VisibilityByTheme } from '@dnb/eufemia/shared'render(<Theme name="..."><VisibilityByTheme visible="sbanken">Only shown in Sbanken theme</VisibilityByTheme><VisibilityByTheme hidden="eiendom">Only hidden in Eiendom theme</VisibilityByTheme><VisibilityByTheme visible={['sbanken', 'eiendom']}>Only shown in Sbanken or Eiendom theme</VisibilityByTheme><VisibilityByThemevisible={[{ name: 'sbanken' }, { name: 'eiendom' }]}>Only shown in Sbanken or Eiendom theme</VisibilityByTheme><VisibilityByThemevisible={[{ name: 'sbanken' }, { name: 'eiendom', variant: 'blue' }]}>Only shown in Sbanken then or Eiendom theme – that also includes thefictive variant="blue".</VisibilityByTheme></Theme>,)
Demos
Basis example
render( <Theme name="sbanken"> <Logo size={40} /> </Theme>, )
propMapping
Basis example Text with custom color
const MyMapping = styled.div` .eufemia-theme__sbanken.eufemia-theme__prop-mapping--my-mapping { --color-sea-green: var(--sb-color-purple-alternative); } ` const CustomComponent = styled(P)` color: var(--color-sea-green); ` render( <MyMapping> <Theme name="sbanken"> <Theme propMapping="my-mapping"> <CustomComponent>Text with custom color</CustomComponent> </Theme> </Theme> </MyMapping>, )