trendingFacets

If you’re using the deprecated recommend-js UI library, see trendingFacets.

Signature

trendingFacets({
  container: string | HTMLElement,
  facetName: string,
  // Optional parameters
  limit?: number,
  threshold?: number,
  fallbackParameters?: object,
  escapeHTML?: boolean,
  templates?: object,
  cssClasses?: object,
  transformItems?: function,
});

Import

import { trendingFacets } from 'instantsearch.js/es/widgets';

const { trendingFacets } = instantsearch.widgets;
// or directly use instantsearch.widgets.trendingFacets()

Use the trendingFacets widget to display a list of trending facet values. See also: Set up Algolia Recommend

Examples

JavaScript

trendingFacets({
  container: "#trendingFacets",
  facetName: "brand",
  templates: {
    item(item, { html }) {
      return html`<span>${item.facetValue}</span>`;
    },
  },
});

Options

container

string | HTMLElement

required

The CSS Selector or HTMLElement to insert the widget into.

trendingFacets({
  // ...
  container: '#trendingFacets',
});

trendingFacets({
  container: document.querySelector("#trendingFacets"),
});

facetName

string

required

The facet attribute to get trending values for.

JavaScript

trendingFacets({
  // ...
  facetName: "brand",
});

limit

number

The number of trending facet values to retrieve. Depending on the available recommendations and the other request parameters, the actual number of items may be lower than that. If limit isn’t provided or set to 0, all matching recommendations are returned.

JavaScript

trendingFacets({
  // ...
  limit: 4,
});

threshold

number

The threshold for the recommendations confidence score (between 0 and 100). Only recommendations with a greater score are returned.

JavaScript

trendingFacets({
  // ...
  threshold: 80,
});

fallbackParameters

Omit<SearchParameters, 'page' | 'hitsPerPage' | 'offset' | 'length'>

List of search parameters to send when there aren’t enough recommendations.

JavaScript

trendingFacets({
  // ...
  fallbackParameters: {
    filters: "category:Book",
  },
});

escapeHTML

boolean

default:true

Escapes HTML entities from recommendations string values.

JavaScript

trendingFacets({
  // ...
  escapeHTML: false,
});

templates

object

The templates to use for the widget.

JavaScript

trendingFacets({
  // ...
  templates: {
    // ...
  },
});

cssClasses

object

default:"{}"

The CSS classes you can override:

root. The widget’s root element.
emptyRoot. The container element without results.
title. The widget’s title element.
container. The container of the list element.
list. The list of trending facet values.
item. The list item.

JavaScript

trendingFacets({
  // ...
  cssClasses: {
    root: "MyCustomTrendingFacets",
    list: ["MyCustomTrendingFacets", "MyCustomTrendingFacets--subclass"],
  },
});

transformItems

function

default:"items => items"

A function that receives the list of items before they are displayed. It should return a new array with the same structure. Use this to transform, filter, or reorder the items.The function also has access to the full results data, including all standard response parameters and parameters from the helper, such as disjunctiveFacetsRefinements.

JavaScript

trendingFacets({
  // ...
  transformItems(items) {
    return items.map((item) => ({
      ...item,
      facetValue: item.facetValue.toUpperCase(),
    }));
  },
});

Templates

You can customize parts of a widget’s UI using the Templates API. Each template includes an html function, which you can use as a tagged template. This function safely renders templates as HTML strings and works directly in the browser—no build step required. For details, see Templating your UI.

The html function is available in InstantSearch.js version 4.46.0 or later.

empty

string | function

The template to use when there are no trending facet values.

trendingFacets({
  // ...
  templates: {
    empty(_, { html }) {
      return html`<p>No trending facets.</p>`;
    },
  },
});

// String-based templates are deprecated, use functions instead.
trendingFacets({
  // ...
  templates: {
    empty: "No trending facets.",
  },
});

header

string | function

The template to use for the widget header. This template receives the items as well as the cssClasses object.

trendingFacets({
  // ...
  templates: {
    header({ cssClasses, items }, { html }) {
      return html`<h2 class=${cssClasses.title}>
        Trending (${items.length})
      </h2>`;
    },
  },
});

// String-based templates are deprecated, use functions instead.
trendingFacets({
  // ...
  templates: {
    header: "<h2>Trending ({{items.length}})</h2>",
  },
});

item

string | function

The template to use for each trending facet value. This template receives an object with facetName, facetValue, and _score.

trendingFacets({
  // ...
  templates: {
    item(item, { html }) {
      return html`<span>${item.facetValue}</span>`;
    },
  },
});

// String-based templates are deprecated, use functions instead.
trendingFacets({
  // ...
  templates: {
    item: `{{ facetValue }}`,
  },
});

HTML output

HTML

<section class="ais-TrendingFacets">
  <h3 class="ais-TrendingFacets-title">Trending</h3>
  <div class="ais-TrendingFacets-container">
    <ol class="ais-TrendingFacets-list">
      <li class="ais-TrendingFacets-item">...</li>
      <li class="ais-TrendingFacets-item">...</li>
      <li class="ais-TrendingFacets-item">...</li>
    </ol>
  </div>
</section>

Customize the UI with `connectTrendingFacets`

If you want to create your own UI of the trendingFacets widget, you can use connectors. To use connectTrendingFacets, you can import it with the declaration relevant to how you installed InstantSearch.js.

import { connectTrendingFacets } from 'instantsearch.js/es/connectors';

const { connectTrendingFacets } = instantsearch.connectors;
// or directly use instantsearch.connectors.connectTrendingFacets()

Then it’s a 3-step process:

JavaScript

// 1. Create a render function
const renderTrendingFacets = (renderOptions, isFirstRender) => {
  // Rendering logic
};

// 2. Create the custom widget
const customTrendingFacets = connectTrendingFacets(renderTrendingFacets);

// 3. Instantiate
search.addWidgets([
  customTrendingFacets({
    // instance params
  }),
]);

Create a render function

This rendering function is called before the first search (init lifecycle step) and each time results come back from Algolia (render lifecycle step).

JavaScript

const renderTrendingFacets = (renderOptions, isFirstRender) => {
  const { items, widgetParams } = renderOptions;

  if (isFirstRender) {
    // Do some initial rendering and bind events
  }

  // Render the widget
};

Rendering options

items

object[]

The trending facet values from the Algolia Recommend API. Each item has facetName, facetValue, and _score properties.

JavaScript

const renderTrendingFacets = (renderOptions, isFirstRender) => {
  const { items } = renderOptions;

  document.querySelector('#trendingFacets').innerHTML = `
    <ul>
      ${items
        .map(item => `<li>${item.facetValue}</li>`)
        .join('')}
    </ul>
  `;
};

All original widget options forwarded to the render function.

JavaScript

const renderTrendingFacets = (renderOptions, isFirstRender) => {
  const { widgetParams } = renderOptions;

  widgetParams.container.innerHTML = '...';
};

// ...

search.addWidgets([
  customTrendingFacets({
    // ...
    container: document.querySelector('#trendingFacets'),
  })
]);

First, create your custom widgets using a rendering function. Then, instantiate them with parameters. There are two kinds of parameters you can pass:

Instance parameters. Predefined options that configure Algolia’s behavior.
Custom parameters. Parameters you define to make the widget reusable and adaptable.

Inside the renderFunction, both instance and custom parameters are accessible through connector.widgetParams.

JavaScript

const customTrendingFacets = connectTrendingFacets(
  renderTrendingFacets
);

search.addWidgets([
  customTrendingFacets({
    // Required parameter
    facetName: string,
    // Optional parameters
    limit: number,
    threshold: number,
    fallbackParameters: object,
    escapeHTML: boolean,
    transformItems: function,
  })
]);

Instance options

facetName

string

required

The facet attribute to get trending values for.

JavaScript

customTrendingFacets({
  // ...
  facetName: "brand",
});

limit

number

JavaScript

customTrendingFacets({
  // ...
  limit: 4,
});

threshold

number

The threshold for the recommendations confidence score (between 0 and 100). Only recommendations with a greater score are returned.

JavaScript

customTrendingFacets({
  // ...
  threshold: 80,
});

fallbackParameters

Omit<SearchParameters, 'page' | 'hitsPerPage' | 'offset' | 'length'>

List of search parameters to send when there aren’t enough recommendations.

JavaScript

customTrendingFacets({
  // ...
  fallbackParameters: {
    filters: "category:Book",
  },
});

escapeHTML

boolean

default:true

Escapes HTML entities from recommendations string values.

JavaScript

customTrendingFacets({
  // ...
  escapeHTML: false,
});

transformItems

function

default:"items => items"

JavaScript

customTrendingFacets({
  // ...
  transformItems(items) {
    return items.map((item) => ({
      ...item,
      facetValue: item.facetValue.toUpperCase(),
    }));
  },
});

Full example

<div id="trendingFacets"></div>

// Create the render function
const renderTrendingFacets = (renderOptions, isFirstRender) => {
  const { items, widgetParams } = renderOptions;

  widgetParams.container.innerHTML = `
    <ul>
      ${items
        .map(item => `<li>${item.facetValue}</li>`)
        .join('')}
    </ul>
  `;
};

// Create the custom widget
const customTrendingFacets = connectTrendingFacets(
  renderTrendingFacets
);

// Instantiate the custom widget
search.addWidgets([
  customTrendingFacets({
    container: document.querySelector('#trendingFacets'),
    facetName: 'brand',
  })
]);

InstantSearch.js

Import

About this widget

Examples

Options

Templates

HTML output

Customize the UI with `connectTrendingFacets`

Create a render function

Rendering options

Create and instantiate the custom widget

Instance options

Full example

​Import

​About this widget

​Examples

​Options

​Templates

​HTML output

​Customize the UI with connectTrendingFacets

​Create a render function

​Rendering options

​Create and instantiate the custom widget

​Instance options

​Full example

Import

About this widget

Examples

Options

Templates

HTML output

Customize the UI with `connectTrendingFacets`

Create a render function

Rendering options

Create and instantiate the custom widget

Instance options

Full example