useBuyerJourneyIntercept

Installs a function for intercepting and preventing progress on checkout. To block checkout progress, you must set the [block_progress](/docs/api/checkout-ui-extensions/configuration#block-progress) capability in your extension's configuration. If you do, then you're expected to inform the buyer why navigation was blocked, either by passing validation errors to the checkout UI or rendering the errors in your extension.

Block progress and show error for a checkout UI field

import React from 'react';
import {
  render,
  useBuyerJourneyIntercept,
  useShippingAddress,
} from '@shopify/checkout-ui-extensions-react';

render(
  'Checkout::DeliveryAddress::RenderBefore',
  () => ,
);

function Extension() {
  const address = useShippingAddress();

  useBuyerJourneyIntercept(
    ({canBlockProgress}) => {
      return canBlockProgress &&
        address?.countryCode &&
        address.countryCode !== 'CA'
        ? {
            behavior: 'block',
            reason: 'Invalid shipping country',
            errors: [
              {
                message:
                  'Sorry, we can only ship to Canada',
                // Show an error underneath the country code field
                target:
                  '$.cart.deliveryGroups[0].deliveryAddress.countryCode',
              },
              {
                // In addition, show an error at the page level
                message:
                  'Please use a different address.',
              },
            ],
          }
        : {
            behavior: 'allow',
          };
    },
  );

  return null;
}

UseBuyerJourneyInterceptGeneratedType

Returns: void

Params:

interceptor: Interceptor

export function useBuyerJourneyIntercept< ID extends RenderExtensionPoint = RenderExtensionPoint, >(interceptor: Interceptor): void { const buyerJourney = useApi<ID>().buyerJourney; const interceptorRef = useRef(interceptor); interceptorRef.current = interceptor; useEffect(() => { const teardownPromise = buyerJourney.intercept((interceptorProps) => interceptorRef.current(interceptorProps), ); return () => { teardownPromise.then((teardown) => teardown()).catch(() => {}); }; }, [buyerJourney]); }

Interceptor

A function for intercepting and preventing navigation on checkout. You can block navigation by returning an object with `{behavior: 'block', reason: InvalidResultReason.InvalidExtensionState, errors?: ValidationErrors[]}`. If you do, then you're expected to also update some part of your UI to reflect the reason why navigation was blocked, either by targeting checkout UI fields, passing errors to the page level or rendering the errors in your extension.

( interceptorProps: InterceptorProps, ) => InterceptorRequest | Promise<InterceptorRequest>

InterceptorProps

canBlockProgress

Whether the interceptor has the capability to block a buyer's progress through checkout. This ability might be granted by a merchant in differing checkout contexts.

InterceptorRequest

InterceptorRequestAllow | InterceptorRequestBlock

InterceptorRequestAllow

behavior

Indicates that the interceptor will allow the buyer's journey to continue.

perform

This callback is called when all interceptors finish. We recommend setting errors or reasons for blocking at this stage, so that all the errors in the UI show up at once.

InterceptorResult

InterceptorResultAllow | InterceptorResultBlock

InterceptorResultAllow

behavior

Indicates that the buyer was allowed to progress through checkout.

InterceptorResultBlock

behavior

Indicates that some part of the checkout UI intercepted and prevented the buyer’s progress. The buyer typically needs to take some action to resolve this issue and to move on to the next step.

InterceptorRequestBlock

behavior

Indicates that the interceptor will block the buyer's journey from continuing.

reason

The reason for blocking the interceptor request. This value isn't presented to the buyer, so it doesn't need to be localized. The value is used only for Shopify’s own internal debugging and metrics.

errors

Used to pass errors to the checkout UI, outside your extension's UI boundaries.

perform

This callback is called when all interceptors finish. We recommend setting errors or reasons for blocking at this stage, so that all the errors in the UI show up at once.

ValidationError

message

Error message to be displayed to the buyer.

target

The checkout UI field that the error is associated with. Example: `$.cart.deliveryGroups[0].deliveryAddress.countryCode` See the [supported targets](/docs/api/functions/reference/cart-checkout-validation/graphql#supported-targets) for more information.

InterceptorRequestBlock

Block the buyer from proceeding further in the checkout

InterceptorRequestBlock

behavior

Indicates that the interceptor will block the buyer's journey from continuing.

reason

errors

Used to pass errors to the checkout UI, outside your extension's UI boundaries.

perform

This callback is called when all interceptors finish. We recommend setting errors or reasons for blocking at this stage, so that all the errors in the UI show up at once.

ValidationError

message

Error message to be displayed to the buyer.

target

InterceptorResult

InterceptorResultAllow | InterceptorResultBlock

InterceptorResultAllow

behavior

Indicates that the buyer was allowed to progress through checkout.

InterceptorResultBlock

behavior

Indicates that some part of the checkout UI intercepted and prevented the buyer’s progress. The buyer typically needs to take some action to resolve this issue and to move on to the next step.

InterceptorRequestAllow

Allow the buyer to proceed further in the checkout

InterceptorRequestAllow

behavior

Indicates that the interceptor will allow the buyer's journey to continue.

perform

This callback is called when all interceptors finish. We recommend setting errors or reasons for blocking at this stage, so that all the errors in the UI show up at once.

InterceptorResult

InterceptorResultAllow | InterceptorResultBlock

InterceptorResultAllow

behavior

Indicates that the buyer was allowed to progress through checkout.

InterceptorResultBlock

behavior

Indicates that some part of the checkout UI intercepted and prevented the buyer’s progress. The buyer typically needs to take some action to resolve this issue and to move on to the next step.

Examples

Intercept and prevent a buyer's progress through checkout while displaying an error message at the page level. See the [validation tutorial](/docs/apps/checkout/validation) for more examples and best practices.

Block progress and show error at page level

import React from 'react';
import {
  render,
  useBuyerJourneyIntercept,
  useShippingAddress,
} from '@shopify/checkout-ui-extensions-react';

render(
  'Checkout::DeliveryAddress::RenderBefore',
  () => ,
);

function Extension() {
  const address = useShippingAddress();

  useBuyerJourneyIntercept(
    ({canBlockProgress}) => {
      return canBlockProgress &&
        address?.countryCode &&
        address.countryCode !== 'CA'
        ? {
            behavior: 'block',
            reason: 'Invalid shipping country',
            errors: [
              {
                // An error without a `target` property is shown at page level
                message:
                  'Sorry, we can only ship to Canada',
              },
            ],
          }
        : {
            behavior: 'allow',
          };
    },
  );

  return null;
}

Block progress and show error at page level

import React from 'react';
import {
  render,
  useBuyerJourneyIntercept,
  useShippingAddress,
} from '@shopify/checkout-ui-extensions-react';

render(
  'Checkout::DeliveryAddress::RenderBefore',
  () => ,
);

function Extension() {
  const address = useShippingAddress();

  useBuyerJourneyIntercept(
    ({canBlockProgress}) => {
      return canBlockProgress &&
        address?.countryCode &&
        address.countryCode !== 'CA'
        ? {
            behavior: 'block',
            reason: 'Invalid shipping country',
            errors: [
              {
                // An error without a `target` property is shown at page level
                message:
                  'Sorry, we can only ship to Canada',
              },
            ],
          }
        : {
            behavior: 'allow',
          };
    },
  );

  return null;
}

Intercept and prevent a buyer's progress through checkout while displaying an error message in your extension. See the [validation tutorial](/docs/apps/checkout/validation) for more examples and best practices.

Block progress and show error in your extension

import React, {useState} from 'react';
import {
  render,
  Banner,
  useBuyerJourneyIntercept,
  useTarget,
} from '@shopify/checkout-ui-extensions-react';

render(
  'Checkout::CartLineDetails::RenderAfter',
  () => ,
);

function Extension() {
  const [showError, setShowError] =
    useState(false);
  const {quantity} = useTarget();

  useBuyerJourneyIntercept(
    ({canBlockProgress}) => {
      return canBlockProgress && quantity > 1
        ? {
            behavior: 'block',
            reason: 'limited stock',
            perform: (result) => {
              if (result.behavior === 'block') {
                setShowError(true);
              }
            },
          }
        : {
            behavior: 'allow',
            perform: () => {
              setShowError(false);
            },
          };
    },
  );

  return showError ? (
    
      This item has a limit of one per customer.
    
  ) : null;
}

Block progress and show error in your extension

import React, {useState} from 'react';
import {
  render,
  Banner,
  useBuyerJourneyIntercept,
  useTarget,
} from '@shopify/checkout-ui-extensions-react';

render(
  'Checkout::CartLineDetails::RenderAfter',
  () => ,
);

function Extension() {
  const [showError, setShowError] =
    useState(false);
  const {quantity} = useTarget();

  useBuyerJourneyIntercept(
    ({canBlockProgress}) => {
      return canBlockProgress && quantity > 1
        ? {
            behavior: 'block',
            reason: 'limited stock',
            perform: (result) => {
              if (result.behavior === 'block') {
                setShowError(true);
              }
            },
          }
        : {
            behavior: 'allow',
            perform: () => {
              setShowError(false);
            },
          };
    },
  );

  return showError ? (
    
      This item has a limit of one per customer.
    
  ) : null;
}

useBuyerJourneyIntercept

Block progress and show error for a checkout UI field