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Crossing Minds Hydrogen Demo Store

This repository contains a demo store using Shopify's Hydrogen together with our recommendation client Beam React. Hydrogen is Shopify’s stack for headless commerce, designed to dovetail with Remix, Shopify’s full stack web framework.

Installation

Requirements:

Getting started

In order to get the project up and running, you need to configure Shopify, configure Beam and then run pnpm to have the app running locally.

Shopify configuration

Copy .env.example to .env and update the values with the ones for you store. If you need more information about those values, you can check the documentation here.

Beam configuration

To configure Beam, you need to set 3 parameters in app/beam/config.tsx:

Run project

Once the configuration is completed, you can run project locally with:

pnpm install
pnpm dev

Implementing recommendations

Description

In a Hydrogen project, since Remix is used, we can render both on the server and on the client. Everything that we want to render on the server, we must do it using the loader function of each of the routes, and everything that we want to render on the client, we can do it using the action function and fetcher.

In the case of recommendations, the decision of where to render will be determined by where the recommendations are obtained.

Server side recommendations

Whenever possible, it's best to render on the server, so recommendations will need to be fetched on the server. Here is an example of a route that gets recommendations and renders them to the server:

export const loader = async ({context, request}: LoaderArgs) => {
  const {sessionId} = await getSessionAndSessionId(request);

  const {itemIds: variantIdsForOurFavorites} =
    await getPersonalizedRecommendations({
      ...BEAM_REACT_OPTIONS,
      sessionId,
      sessionScenario: 'some scenario id',
      maxResults: 8,
    });

  const {nodes: productVariants} = await context.storefront.query<Promise<any>>(
    PRODUCTS_BY_VARIANT_QUERY,
    {
      variables: variantIdsForOurFavorites.map(
        (variantId) => `gid://shopify/ProductVariant/${variantId}`,
      ),
    },
  );

  return json({productVariants});
};

export const shouldRevalidate = () => false;

export default function Index() {
  const {productVariants} = useLoaderData<typeof loader>();

  return (
    <div>
      <Recommendations productVariants={productVariants} />
    </div>
  );
}

The first step is to obtain the IDs of the recommendations (they can be products or, as in the case of the home page of the same demo store, collections):

const {itemIds: variantIdsForOurFavorites} =
  await getPersonalizedRecommendations({
    ...BEAM_REACT_OPTIONS,
    sessionId,
    sessionScenario: 'some scenario id',
    maxResults: 8,
  });

With that list of IDs (in the example product variants), we can use Shopify's GraphQL API to get the product variants:

const {nodes: productVariants} = await context.storefront.query<Promise<any>>(
  PRODUCTS_BY_VARIANT_QUERY,
  {
    variables: variantIdsForOurFavorites.map(
      (variantId) => `gid://shopify/ProductVariant/${variantId}`,
    ),
  },
);

Once obtained, we will pass them by returning them in the loader function:

return json({productVariants});

And now, the React component will be able to obtain and paint them or pass them as a parameter to other components:

const {productVariants} = useLoaderData<typeof loader>();

return (
  <div>
    <Recommendations productVariants={productVariants} />
  </div>
);

It is important to understand this line of code that is indicated in the route. When using fetcher, Remix by default fetches a parallel version of the same page we are on, and replaces it with the current one, resulting in a re-render. To avoid this, in those routes that we do not want to have said automatic update, we can indicate that it should not revalidate.

export const shouldRevalidate = () => false;

Client side recommendations

There may be cases where we need client data to customize recommendations, so we won't be able to render them directly on the server. This is the example of the recommendations that appear in the cart drawer of the demo store. These recommendations are customized according to what products are in the cart, so we cannot obtain them like any other route, since there is no complete navigation.

In these cases, the correct thing to do is to use a specific route that will serve as an "endpoint" to obtain the recommendations and their associated products. This is where the action function of the route and the use of fetcher come into play.

import {type LoaderArgs, json, redirect} from '@shopify/remix-oxygen';

import {PRODUCTS_BY_VARIANT_QUERY} from '~/queries/product';
import {SHOPIFY_ENTITY_TYPES, getShopifyEntityIdFromId} from '~/utils/shopify';

export async function action({request, context}: LoaderArgs) {
  const [formData] = await Promise.all([request.formData()]);
  let itemIds: string[] = [];

  try {
    itemIds = JSON.parse((formData.get('itemIds') as string) || '') as string[];
  } catch {
    return json({nodes: []});
  }

  const {nodes} = await context.storefront.query<Promise<any>>(
    PRODUCTS_BY_VARIANT_QUERY,
    {
      variables: {
        ids: (itemIds as string[]).map((itemId) =>
          getShopifyEntityIdFromId(
            SHOPIFY_ENTITY_TYPES.PRODUCT_VARIANT,
            itemId,
          ),
        ),
      },
    },
  );

  return json(nodes);
}

export const loader = async () => {
  return redirect('/');
};

export default function CartRecommendations() {
  return <></>;
}

The first thing is to have a route with the action function implemented. That function will receive the parameters that we pass to it in the request body.

const [formData] = await Promise.all([request.formData()]);
let itemIds: string[] = [];

try {
  itemIds = JSON.parse((formData.get('itemIds') as string) || '') as string[];
} catch {
  return json({nodes: []});
}

Now we can use those IDs to obtain the product variants using the GraphQL API from Shopify.

const {nodes} = await context.storefront.query<Promise<any>>(
  PRODUCTS_BY_VARIANT_QUERY,
  {
    variables: {
      ids: (itemIds as string[]).map((itemId) =>
        getShopifyEntityIdFromId(SHOPIFY_ENTITY_TYPES.PRODUCT_VARIANT, itemId),
      ),
    },
  },
);

Finally, a JSON is returned in the same way with all the data that our components need.

return json(nodes);

Since we've created a new route, that means our route could be accessible via a URL like any other page. To avoid this, in addition to not returning anything in the main function (safety belt), the important thing is to make a redirect to where we consider within the loader function. In the case of the example, a redirection is made to the home page.

export const loader = async () => {
  return redirect('/');
};

export default function CartRecommendations() {
  return <></>;
}

Now that we have our "endpoint", the way to call it is using fetcher. The component that is responsible for getting the recommendations will make a call to the route we have created by submitting a form.

const contextItems = cart.lines.edges.map((lineEdge) => {
  return {
    itemId: getIdFromShopifyEntityId(
      SHOPIFY_ENTITY_TYPES.PRODUCT_VARIANT,
      lineEdge.node.merchandise.id,
    ),
  };
});

const {itemIds} = await getPersonalizedRecommendations({
  ...BEAM_REACT_OPTIONS,
  sessionId,
  contextItems,
  sessionWithContextScenario:
    RECOMMENDATION_SCENARIOS.CART_FREQUENTLY_PURCHASED_TOGETHER,
  maxResults: 8 + contextItems.length,
});

fetcher.submit(
  {itemIds: JSON.stringify(itemIds)},
  {method: 'post', action: '/cartRecommendations'},
);

That call will be captured by fetcher, processed and made available to our component using fetcher.data (a complete example of this can be found in app/hooks/useCartRecommendations.tsx).

useEffect(() => {
  if (fetcher.state === 'idle' && fetcher.data) {
    setCartRecommendations(removeRepeatedCartRecommendations(fetcher.data));
    setCartRecommendationsLoading(false);
    setCartRecommendationsError(false);
  }
}, [fetcher]);

Summary

As we have seen, despite the fact that rendering can be done both on the server and on the client, obtaining the data from the Shopify GraphQL API is always done on the server.