RecommendationList

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Developer

In this article

Example Implementation
Methods
Attributes
Initialize
Related Types

Example Implementation

recommendation-list.fn.tsx

import {
  RecommendationList as HeadlessRecommendationList,
  loadClickAnalyticsActions,
  Result,
} from '@coveo/headless/recommendation';
import {useEffect, useState, FunctionComponent, useContext} from 'react';
import {AppContext} from '../../context/engine';
import {filterProtocol} from '../../utils/filter-protocol';
 
interface RecommendationListProps {
  controller: HeadlessRecommendationList;
}
 
export const RecommendationList: FunctionComponent<RecommendationListProps> = (
  props
) => {
  const engine = useContext(AppContext).recommendationEngine;
  const {controller} = props;
  const [state, setState] = useState(controller.state);
 
  useEffect(() => controller.subscribe(() => setState(controller.state)), []);
 
  if (state.error) {
    return (
      <div>
        <div>Oops {state.error.message}</div>
        <code>{JSON.stringify(state.error)}</code>
        <button onClick={() => controller.refresh()}>Try again</button>
      </div>
    );
  }
 
  if (!state.recommendations.length) {
    return <button onClick={() => controller.refresh()}>Refresh</button>;
  }
 
  const logClick = (recommendation: Result) => {
    if (!engine) {
      return;
    }
 
    const {logRecommendationOpen} = loadClickAnalyticsActions(engine);
    engine.dispatch(logRecommendationOpen(recommendation));
  };
 
  return (
    <div>
      <button onClick={() => controller.refresh()}>Refresh</button>
      <ul style={{textAlign: 'left'}}>
        {state.recommendations.map((recommendation) => (
          <li key={recommendation.uniqueId}>
            <article>
              <h2>
                {/* Make sure to log analytics when the recommendation is clicked. */}
                <a
                  href={filterProtocol(recommendation.clickUri)} // Filters out dangerous URIs that can create XSS attacks such as `javascript:`.
                  onClick={() => logClick(recommendation)}
                  onContextMenu={() => logClick(recommendation)}
                  onMouseDown={() => logClick(recommendation)}
                  onMouseUp={() => logClick(recommendation)}
                >
                  {recommendation.title}
                </a>
              </h2>
              <p>{recommendation.excerpt}</p>
            </article>
          </li>
        ))}
      </ul>
    </div>
  );
};
 
// usage
 
/**
 * ```tsx
 * const controller = buildRecommendationList(recommendationEngine, {
 *   options: {id: 'Recommendation'},
 * });
 *
 * <RecommendationList controller={controller} />;
 * ```
 */

The RecommendationList controller retrieves information about the current recommendations by the search API, if there are any.

Methods

`refresh`

Gets new recommendations.

`subscribe`

Adds a callback that’s invoked on state change.

Parameters

listener: () => void

A callback that’s invoked on state change.

Returns Unsubscribe: A function to remove the listener.

Attributes

`state`

The state relevant to the RecommendationList controller.

Properties

error: ErrorPayload | null

The current error for the last executed query, or null if none is present.
isLoading: boolean

true if a search is in progress and false otherwise.
recommendations: Result[]

The recommendations based on the last executed query.
searchResponseId: string

The unique identifier of the Search API response from which the recommendations were fetched.

Initialize

`buildRecommendationList`

Creates a RecommendationList controller instance.

Parameters

engine: RecommendationEngine

The headless engine.
props: RecommendationListProps

The configurable RecommendationList properties.

Returns RecommendationList