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Routing URLs

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You are currently reading the documentation for InstantSearch.js V4. Read our migration guide to learn how to upgrade from V3 to V4. You can still access the V3 documentation for this page.

Overview

InstantSearch.js provides the necessary API entries to let you synchronize the state of your search UI (e.g., refined widgets, current search query) with any kind of storage. This is possible with the routing option. This guide focuses on storing the UI state in the browser URL.

Synchronizing your UI with the browser URL is a good practice. It allows your users to take one of your results pages, copy the URL, and share it. It also improves the user experience by enabling the use of the back and next browser buttons to keep track of previous searches.

By the end of this guide, you will be able to reproduce these examples:

Basic URLs

InstantSearch.js provides a basic way to activate the browser URL synchronization with the routing option set to true. You can find a live example on this sandbox.

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const search = instantsearch({
  searchClient,
  indexName: 'instant_search',
  routing: true
});

Assume the following search UI state:

  • Query: “galaxy”
  • Menu:
    • categories: “Cell Phones”
  • Refinement List:
    • brand: “Apple”, “Samsung”
  • Page: 2

The resulting URL in your browser URL bar will look like this:

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https://website.com/?instant_search[query]=galaxy&instant_search[menu][categories]=All Unlocked Cell Phones&instant_search[refinementList][brand][0]=Apple&instant_search[refinementList][brand][0]=Samsung&instant_search[page]=2

This URL is accurate, and can be translated back to a search UI state. However, we’ll see in the next section how to make it more SEO-friendly.

Rewriting URLs manually

The default URLs that InstantSearch generates are comprehensive, but if you have many widgets, this can also generate noise. You may want to decide what goes in the URL and what doesn’t, or even rename the query parameters to something that makes more sense to you.

Setting routing to true is syntactic sugar for the following code:

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const search = instantsearch({
  searchClient,
  indexName: 'instant_search',
  routing: {
    router: instantsearch.routers.history(),
    stateMapping: instantsearch.stateMappings.simple(),
  },
});

The stateMapping defines how to go from InstantSearch’s internal state to a URL, and vice versa. You can override it to rename query parameters and choose what to include in the URL.

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const search = instantsearch({
  searchClient,
  indexName: 'instant_search',
  routing: {
    stateMapping: {
      stateToRoute(uiState) {
        // ...
      },
      routeToState(routeState) {
        // ...
      },
    },
  },
});

InstantSearch manages a state called uiState. It contains information like query, facets, or the current page, including the hierarchy of the added widgets.

To persist this state in the URL, InstantSearch first converts the uiState into an object called routeState. This routeState then becomes a URL. Conversely, when InstantSearch reads the URL and applies it to the search, it converts routeState into uiState. This logic lives in two functions:

  • stateToRoute: converts uiState to routeState.
  • routeToState: converts routeState to uiState.

Assume the following search UI state:

  • Query: “galaxy”
  • Menu:
    • categories: “Cell Phones”
  • Refinement List:
    • brand: “Apple” and “Samsung”
  • Page: 2

This translates into the following uiState:

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{
  "your-index-name": {
    "query": "galaxy",
    "menu": {
      "categories": "Cell Phones",
    },
    "refinementList": {
      "brand": ["Apple", "Samsung"],
    },
    "page": 2,
  },
}

You can implement stateToRoute to flatten this object into a URL, and routeToState to restore the URL into a UI state:

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const indexName = 'instant_search';

const search = instantsearch({
  searchClient,
  indexName,
  routing: {
    stateMapping: {
      stateToRoute(uiState) {
        const indexUiState = uiState[indexName];
        return {
          q: indexUiState.query,
          categories: indexUiState.menu && indexUiState.menu.categories,
          brand:
            indexUiState.refinementList && indexUiState.refinementList.brand,
          page: indexUiState.page,
        }
      },
      routeToState(routeState) {
        return {
          [indexName]: {
            query: routeState.q,
            menu: {
              categories: routeState.categories,
            },
            refinementList: {
              brand: routeState.brand,
            },
            page: routeState.page,
          },
        };
      },
    },
  },
});

SEO-friendly URLs

URLs are more than query parameters. Another important part is the path. Manipulating the URL path is a common e-commerce pattern that allows you to better reference your page results. In this section, you’ll learn how to create this kind of URLs:

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https://website.com/search/Cell+Phones/?query=galaxy&page=2&brands=Apple&brands=Samsung

Example of implementation

Here’s an example storing the brand in the path name, and the query and page as query parameters. You can find a live example on this sandbox.

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// Returns a slug from the category name.
// Spaces are replaced by "+" to make
// the URL easier to read and other
// characters are encoded.
function getCategorySlug(name) {
  return name
    .split(' ')
    .map(encodeURIComponent)
    .join('+');
}

// Returns a name from the category slug.
// The "+" are replaced by spaces and other
// characters are decoded.
function getCategoryName(slug) {
  return slug
    .split('+')
    .map(decodeURIComponent)
    .join(' ');
}

const search = instantsearch({
  searchClient,
  indexName: 'instant_search',
  routing: {
    router: instantsearch.routers.history({
      windowTitle({ category, query }) {
        const queryTitle = query ? `Results for "${query}"` : 'Search';

        if (category) {
          return `${category} – ${queryTitle}`;
        }

        return queryTitle;
      },

      createURL({ qsModule, routeState, location }) {
        const urlParts = location.href.match(/^(.*?)\/search/);
        const baseUrl = `${urlParts ? urlParts[1] : ''}/`;

        const categoryPath = routeState.category
          ? `${getCategorySlug(routeState.category)}/`
          : '';
        const queryParameters = {};

        if (routeState.query) {
          queryParameters.query = encodeURIComponent(routeState.query);
        }
        if (routeState.page !== 1) {
          queryParameters.page = routeState.page;
        }
        if (routeState.brands) {
          queryParameters.brands = routeState.brands.map(encodeURIComponent);
        }

        const queryString = qsModule.stringify(queryParameters, {
          addQueryPrefix: true,
          arrayFormat: 'repeat'
        });

        return `${baseUrl}search/${categoryPath}${queryString}`;
      },

      parseURL({ qsModule, location }) {
        const pathnameMatches = location.pathname.match(/search\/(.*?)\/?$/);
        const category = getCategoryName(
          (pathnameMatches && pathnameMatches[1]) || ''
        );
        const { query = '', page, brands = [] } = qsModule.parse(
          location.search.slice(1)
        );
        // `qs` does not return an array when there's a single value.
        const allBrands = Array.isArray(brands)
          ? brands
          : [brands].filter(Boolean);

        return {
          query: decodeURIComponent(query),
          page,
          brands: allBrands.map(decodeURIComponent),
          category
        };
      }
    }),

    stateMapping: {
      stateToRoute(uiState) {
        const indexUiState = uiState['instant_search'] || {};

        return {
          query: indexUiState.query,
          page: indexUiState.page,
          brands: indexUiState.refinementList && indexUiState.refinementList.brand,
          category: indexUiState.menu && indexUiState.menu.categories
        };
      },

      routeToState(routeState) {
        return {
          instant_search: {
            query: routeState.query,
            page: routeState.page,
            menu: {
              categories: routeState.category
            },
            refinementList: {
              brand: routeState.brands
            }
          }
        };
      }
    }
  }
});

We are now using the instantsearch.routers.history to explicitly set options on the default router mechanism used in the previous example. You can notice that we use both the router and stateMapping options to map uiState to routeState, and vice versa.

Using the routing option as an object, we can configure:

  • windowTitle: a method to map the routeState object returned from stateToRoute to the window title.
  • createURL: a method called every time we need to create a URL. When:
    • we want to synchronize the routeState to the browser URL,
    • we want to render a tags in the menu widget,
    • you call createURL in one of your connectors’ rendering methods.
  • parseURL: a method called every time the user loads or reloads the page, or clicks on the back or next buttons of the browser.

Making URLs more discoverable

In real-life applications, you might want to make some categories more easily accessible, with a URL that’s easier to read and to remember.

Given our dataset, we can make some categories more discoverable:

  • “Cameras & Camcorders” → /Cameras
  • “Car Electronics & GPS” → /Cars
  • etc.

In this example, anytime the users visits https://website.com/search/Cameras, it pre-selects the “Cameras & Camcorders” filter.

You can achieve this with a dictionary.

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// Step 1. Add the dictionaries to convert the names and the slugs
const encodedCategories = {
  Cameras: 'Cameras & Camcorders',
  Cars: 'Car Electronics & GPS',
  Phones: 'Cell Phones',
  TV: 'TV & Home Theater'
};

const decodedCategories = Object.keys(encodedCategories).reduce((acc, key) => {
  const newKey = encodedCategories[key];
  const newValue = key;

  return {
    ...acc,
    [newKey]: newValue
  };
}, {});

// Step 2. Update the getters to use the encoded/decoded values
function getCategorySlug(name) {
  const encodedName = decodedCategories[name] || name;

  return encodedName
    .split(' ')
    .map(encodeURIComponent)
    .join('+');
}

function getCategoryName(slug) {
  const decodedSlug = encodedCategories[slug] || slug;

  return decodedSlug
    .split('+')
    .map(decodeURIComponent)
    .join(' ');
}

Note that these dictionaries can come from your Algolia records.

With such a solution, you have full control over what categories are discoverable via the URL.

About SEO

For your search results to be part of search engines results, you have to be selective. Adding too many search results inside search engines could be considered as spam.

To do that, you can create a robots.txt and host it at https://website.com/robots.txt.

Here’s an example based on the URL scheme we created.

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User-agent: *
Allow: /search/Audio/
Allow: /search/Phones/
Disallow: /search/
Allow: *
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InstantSearch.js v4