Accessing data with context

An Autocomplete context lets you store data and access it in different lifecycle hooks.

Autocomplete is also available as an experimental widget in InstantSearch, making it easier to integrate into your search experience. For more information, see the API reference for InstantSearch.js or React InstantSearch.

Use an Autocomplete context to store and share data across your app. For example, when retrieving hits from Algolia, you may want to reuse the total number of results to update a template.

Usage

Context exposes a setContext function, which takes an object and merges it with the existing context. You can then access the context in state.context.

The following example stores the number of hits from an Algolia response, making it accessible everywhere in your autocomplete.

JavaScript

autocomplete({
  // ...
  getSources({ query, setContext }) {
    return [
      {
        sourceId: "products",
        getItems() {
          return getAlgoliaResults({
            searchClient,
            queries: [
              {
                indexName: "instant_search",
                query,
              },
            ],
            transformResponse({ results, hits }) {
              setContext({
                nbProducts: results[0].nbHits,
              });

              // You can now use `state.context.nbProducts`
              // anywhere where you have access to `state`.

              return hits;
            },
          });
        },
        // ...
      },
    ];
  },
});

Context can be handy when developing Autocomplete plugins. It avoids polluting the global namespace while still being able to pass data around across different lifecycle hooks.

JavaScript

function createAutocompletePlugin() {
  return {
    // ...
    subscribe({ setContext }) {
      setContext({
        autocompletePlugin: {
          // ...
        },
      });
    },
  };
}

Reference

The setContext function is accessible on your autocomplete instance.

It’s also provided in:

• getSources
• onSubmit
• onReset
• source.onActive
• source.onSelect
• source.getItems
• plugin.subscribe

The context object is available on the state object.

setContext · (value: Record<string, unknown>) => void

The function to pass data to store it in the context.

context · Record<string,unknown>

The context to read data from.