trendingItems

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

Signature

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

Import

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

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

Use the trendingItems widget to display a list of trending items. See also: Set up Algolia Recommend

Examples

JavaScript

trendingItems({
  container: "#trendingItems",
  facetName: "category",
  facetValue: "Book",
  templates: {
    item(recommendation, { html }) {
      return html`
        <h2>${recommendation.name}</h2>
        <p>${recommendation.description}</p>
      `;
    },
  },
});

With a carousel layout

Display the trendingItems widget as a scrollable carousel.

JavaScript

import { carousel } from "instantsearch.js/es/templates";
// or
const { carousel } = instantsearch.templates;

trendingItems({
  container: "#trendingItems",
  facetName: "category",
  facetValue: "Book",
  templates: {
    item(recommendation, { html }) {
      return html`
        <h2>${recommendation.name}</h2>
        <p>${recommendation.description}</p>
      `;
    },
    layout: carousel(),
  },
});

Options

container

string | HTMLElement

required

The CSS Selector or HTMLElement to insert the widget into.

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

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

facetName

string

The attribute to get recommendations for. Use this parameter with facetValue.

JavaScript

trendingItems({
  // ...
  facetName: "category",
  facetValue: "Book",
});

facetValue

string

The value for the targeted facet name. This parameter should be used along with facetName.

JavaScript

trendingItems({
  // ...
  facetName: "category",
  facetValue: "Book",
});

limit

number

The number of recommendations 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

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

threshold

number

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

JavaScript

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

queryParameters

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

List of search parameters to send.

JavaScript

trendingItems({
  // ...
  queryParameters: {
    filters: "category:Book",
  },
});

fallbackParameters

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

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

JavaScript

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

escapeHTML

boolean

default:true

Escapes HTML entities from recommendations string values.

JavaScript

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

templates

object

The templates to use for the widget.

JavaScript

trendingItems({
  // ...
  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 recommendations.
item. The list item.

JavaScript

trendingItems({
  // ...
  cssClasses: {
    root: "MyCustomTrendingItems",
    list: ["MyCustomTrendingItems", "MyCustomTrendingItems--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

trendingItems({
  // ...
  transformItems(items) {
    return items.map((item) => ({
      ...item,
      name: item.name.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 recommendations.

trendingItems({
  // ...
  templates: {
    empty(_, { html }) {
      return html`<p>No recommendations.</p>`;
    },
  },
});

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

header

string | function

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

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

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

item

string | function

The template to use for each recommendation. This template receives an object containing a single record.

trendingItems({
  // ...
  templates: {
    item(recommendation, { html }) {
      return html`
        <h2>${recommendation.name}</h2>
        <p>${recommendation.description}</p>
      `;
    },
  },
});

// String-based templates are deprecated, use functions instead.
trendingItems({
  // ...
  templates: {
    item: `
      <h2>{{ name }}</h2>
      <p>{{ description }}</p>
    `,
  },
});

layout

function

since: v4.74.0

The template to use to wrap all items.InstantSearch.js provides an out-of-the-box carousel layout template with the following options:cssClasses:

root. The carousel’s root element.
list. The list of recommendations.
item. The list item.
navigation. The navigation controls.
navigationPrevious. The “Previous” navigation control.
navigationNext. The “Next” navigation control.

templates:

previous. The content of the “Previous” navigation control.
next. The content of the “Next” navigation control.

import { carousel } from 'instantsearch.js/es/templates';
// or
const { carousel } = instantsearch.templates;

trendingItems({
  // ...
  templates: {
    layout: carousel({
      cssClasses: {
        root: 'MyCustomCarousel',
      },
      templates: {
        previous({ html }) {
          return html`<p>Previous</p>`;
        },
        next({ html }) {
          return html`<p>Next</p>`;
        },
      },
    }),
  },
});

trendingItems({
  // ...
  templates: {
    layout({ items }, { html }) {
      return html`
        <ul>
          ${items.map((item) => html`<li><p>${item.objectID}</p></li>`)}
        </ul>
      `;
    },
  },
});

HTML output

HTML

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

Customize the UI with `connectTrendingItems`

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

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

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

Then it’s a 3-step process:

JavaScript

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

// 2. Create the custom widget
const customTrendingItems = connectTrendingItems(renderTrendingItems);

// 3. Instantiate
search.addWidgets([
  customTrendingItems({
    // 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 renderTrendingItems = (renderOptions, isFirstRender) => {
  const { items, widgetParams } = renderOptions;

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

  // Render the widget
};

Rendering options

items

object[]

The matched recommendations from the Algolia API.

JavaScript

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

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

All original widget options forwarded to the render function.

JavaScript

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

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

// ...

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

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 customTrendingItems = connectTrendingItems(
  renderTrendingItems
);

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

Instance options

facetName

string

The facet attribute to get recommendations for. This parameter should be used along with facetValue.

JavaScript

customTrendingItems({
  // ...
  facetName: "category",
  facetValue: "Book",
});

facetValue

string

The value for the targeted facet name. This parameter should be used along with facetName.

JavaScript

customTrendingItems({
  // ...
  facetName: "category",
  facetValue: "Book",
});

limit

number

JavaScript

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

threshold

number

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

JavaScript

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

queryParameters

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

List of search parameters to send.

JavaScript

customTrendingItems({
  // ...
  queryParameters: {
    filters: "category:Book",
  },
});

fallbackParameters

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

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

JavaScript

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

escapeHTML

boolean

default:true

Escapes HTML entities from recommendations string values.

JavaScript

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

transformItems

function

default:"items => items"

JavaScript

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

Full example

<div id="trendingItems"></div>

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

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

// Create the custom widget
const customTrendingItems = connectTrendingItems(
  renderTrendingItems
);

// Instantiate the custom widget
search.addWidgets([
  customTrendingItems({
    container: document.querySelector('#trendingItems'),
  })
]);

InstantSearch.js

Import

About this widget

Examples

With a carousel layout

Options

Templates

HTML output

Customize the UI with `connectTrendingItems`

Create a render function

Rendering options

Create and instantiate the custom widget

Instance options

Full example

​Import

​About this widget

​Examples

​With a carousel layout

​Options

​Templates

​HTML output

​Customize the UI with connectTrendingItems

​Create a render function

​Rendering options

​Create and instantiate the custom widget

​Instance options

​Full example

Import

About this widget

Examples

With a carousel layout

Options

Templates

HTML output

Customize the UI with `connectTrendingItems`

Create a render function

Rendering options

Create and instantiate the custom widget

Instance options

Full example