The Volto Slider Block allows editors to add sliders to a Volto page. You can see it in action under www.dlr.de and www.fz-juelich.de.

https://user-images.githubusercontent.com/486927/170819371-6284d8e7-e5df-4893-9dab-cd06b1054505.mov

These are the recommended versions:

Create a new Volto project (you can skip this step if you already have one):

npm install -g yo @plone/generator-volto
yo @plone/volto my-volto-project --addon @kitconcept/volto-slider-block
cd my-volto-project

Add @kitconcept-volto/slider-blockto your package.json:

"addons": [
    "@kitconcept/volto-slider-block"
],

"dependencies": {
    "@kitconcept/volto-slider-block": "*"
}

Download and install the new add-on by running:

yarn install

Start Volto with:

yarn start

Go to http://localhost:3000, login, create a new page. The slider block will show up in the Volto blocks chooser.

This enables the autoplay controls in the block's settings.

config.blocks.blocksConfig.slider.enableAutoPlay = true;

The underlying library used by this block has been changed. Now it uses Embla Caroussel. Embla Caroussel has a similar API and has all the features that react-slick had. Embla is more modern and supported, uses hooks to configure itself and it's extensible using plugins. It solves all the problems that react-slick had, specially in the simplification of the containers and wrappers, and the way it handles the CSS transformations and the width of the elements.

If you've made any CSS customization, the classNames changed, so you'll need to update the CSS following this table.

You can use a Volto schemaEnhancer to modify the existing block schema. The block also can be extended using Volto's block variations.

import { defineMessages } from 'react-intl';
import { pull } from 'lodash';

import SliderDefaultBody from './components/Blocks/Slider/DefaultBody'; // My custom view component for slides

const messages = defineMessages({
  color: {
    id: 'Color',
    defaultMessage: 'Color',
  },
  slideBackgroundColor: {
    id: 'Slide Background Color',
    defaultMessage: 'Slide Background Color',
  },
  flagColor: {
    id: 'Flag color',
    defaultMessage: 'Flag color',
  },
});

const BG_COLORS = [
  { name: 'transparent', label: 'Transparent' },
  { name: 'grey', label: 'Grey' },
];

// The schemaEnhancer
const sliderBlockSchemaEnhancer = ({ formData, schema, intl }) => {
  schema.properties.slides.schema.fieldsets[0].fields.push(
    'slideBackgroundColor',
  );
  schema.properties.slides.schema.properties.slideBackgroundColor = {
    widget: 'color_picker',
    title: intl.formatMessage(messages.slideBackgroundColor),
    colors: BG_COLORS,
    default: 'transparent',
  };
  pull(schema.properties.slides.schema.fieldsets[0].fields, 'description'); // You can remove fields as well
  return schema; // You should return the schema back
};

const applyConfig = (config) => {

  config.blocks.blocksConfig.slider = {
    schemaEnhancer: sliderBlockSchemaEnhancer,
    variations: [
      {
        id: 'default',
        isDefault: true,
        title: 'Default',
        view: SliderDefaultBody,
      },
    ],
  }

More fields can be added to either the block itself or to each slide. You can use the configuration settings to do so:

config.blocks.blocksConfig.slider.extensions = {
  blockSchema: {
    fieldsets: [
      {
        id: 'default',
        title: 'Default',
        fields: ['new_field'],
      },
    ],
    properties: {
      new_field: {
        title: 'New Slider Field',
      },
    },
  },
  slideSchema: {
    fieldsets: [
      {
        id: 'default',
        title: 'Default',
        fields: ['new_field'],
      },
    ],
    properties: {
      new_field: {
        title: 'New Slide Field',
      },
    },
  },
};

The block and slide schemas will be merged with the existing ones.

The Teaser has a data adapter function that allows you to both tap into the changes in the settings and issue changes in other settings fields. This is valuable in the Teaser block because it saves an internal cache of the target element. If you select the target, these values are updated. When you update the target, by default these values remain, but you can issue another behavior.

The data adapter function is defined in the block's setting dataAdapter. You can override it and add your own function, if required. The following is the default adapter. You should stick to this signature in your custom adapters.

import { difference } from '@plone/volto/helpers';
import { replaceItemOfArray } from '@plone/volto/helpers';

export const SliderBlockDataAdapter = ({
  block,
  data,
  id,
  onChangeBlock,
  value,
}) => {
  let dataSaved = {
    ...data,
    [id]: value,
  };

  if (id === 'slides') {
    const diff = difference(value, data[id]);
    const index = diff.findIndex((val) => val);
    if (diff[index]?.href?.[0]) {
      dataSaved = {
        ...dataSaved,
        slides: replaceItemOfArray(value, index, {
          ...value[index],
          title: diff[index].href[0].Title,
          description: diff[index].href[0].Description,
          head_title: diff[index].href[0].head_title,
        }),
      };
    }
  }

  onChangeBlock(block, dataSaved);
};

The development of this plugin has been kindly sponsored by Forschungszentrum Jülich and the German Aerospace Center (DLR).

The project is licensed under the MIT license.