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Theme

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Properties

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.

Mapping of properties with propMapping

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;

  1. 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>,
)
  1. 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>


    <VisibilityByTheme
      visible={[{ name: 'sbanken' }, { name: 'eiendom' }]}
    >
      Only shown in Sbanken or Eiendom theme
    </VisibilityByTheme>


    <VisibilityByTheme
      visible={[{ name: 'sbanken' }, { name: 'eiendom', variant: 'blue' }]}
    >
      Only shown in Sbanken then or Eiendom theme – that also includes the
      fictive variant="blue".
    </VisibilityByTheme>
  </Theme>,
)

Demos

Basis example

render(

  <Theme name="sbanken">

    <Logo size={40} />

  </Theme>,

)

Basis example propMapping

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>,

)