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useBuyerJourneyIntercept

Installs a function for intercepting and preventing progress on checkout.

To block checkout progress, you must set the 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.

Anchor to useBuyerJourneyIntercept
useBuyerJourneyIntercept(
interceptor
)

Anchor to useBuyerJourneyIntercept-parametersParameters

Anchor to interceptor interceptor required

Anchor to useBuyerJourneyIntercept-returnsReturns
void

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.
```
boolean
```

export interface InterceptorProps {
  /**
   * 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.
   */
  canBlockProgress: boolean;
}

InterceptorRequest

InterceptorRequestAllow | InterceptorRequestBlock

InterceptorRequestAllow

behavior
Indicates that the interceptor will allow the buyer's journey to continue.
```
"allow"
```
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.
```
(result: InterceptorResult) => void | Promise<void>
```

interface InterceptorRequestAllow {
  /**
   * Indicates that the interceptor will allow the buyer's journey to continue.
   */
  behavior: 'allow';

  /**
   * 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.
   * @param result InterceptorResult with behavior as either 'allow' or 'block'
   */
  perform?(result: InterceptorResult): void | Promise<void>;
}

InterceptorResult

InterceptorResultAllow | InterceptorResultBlock

InterceptorResultAllow

behavior
Indicates that the buyer was allowed to progress through checkout.
```
"allow"
```

interface InterceptorResultAllow {
  /**
   * Indicates that the buyer was allowed to progress through checkout.
   */
  behavior: 'allow';
}

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.
```
"block"
```

interface InterceptorResultBlock {
  /**
   * 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.
   */
  behavior: 'block';
}

InterceptorRequestBlock

behavior
Indicates that the interceptor will block the buyer's journey from continuing.
```
"block"
```
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.
```
string
```
errors
Used to pass errors to the checkout UI, outside your extension's UI boundaries.
```
ValidationError[]
```
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.
```
(result: InterceptorResult) => void | Promise<void>
```

interface InterceptorRequestBlock {
  /**
   * Indicates that the interceptor will block the buyer's journey from continuing.
   */
  behavior: 'block';

  /**
   * 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.
   */
  reason: string;

  /**
   * Used to pass errors to the checkout UI, outside your extension's UI boundaries.
   */
  errors?: ValidationError[];

  /**
   * 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.
   * @param result InterceptorResult with behavior as either 'allow' or 'block'
   */
  perform?(result: InterceptorResult): void | Promise<void>;
}

ValidationError

message
Error message to be displayed to the buyer.
```
string
```
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.
```
string
```

export interface ValidationError {
  /**
   * Error message to be displayed to the buyer.
   */
  message: string;
  /**
   * 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.
   */
  target?: string;
}

Anchor to interceptorrequestblockInterceptorRequestBlock

Block the buyer from proceeding further in the checkout

Anchor to behavior behavior "block" required: Indicates that the interceptor will block the buyer's journey from continuing.
Anchor to reason reason string required: 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.
Anchor to errors errors []: Used to pass errors to the checkout UI, outside your extension's UI boundaries.
Anchor to perform perform (result: ) => void | Promise<void>: 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.
```
string
```
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.
```
string
```

export interface ValidationError {
  /**
   * Error message to be displayed to the buyer.
   */
  message: string;
  /**
   * 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.
   */
  target?: string;
}

InterceptorResult

InterceptorResultAllow | InterceptorResultBlock

InterceptorResultAllow

behavior
Indicates that the buyer was allowed to progress through checkout.
```
"allow"
```

interface InterceptorResultAllow {
  /**
   * Indicates that the buyer was allowed to progress through checkout.
   */
  behavior: 'allow';
}

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.
```
"block"
```

interface InterceptorResultBlock {
  /**
   * 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.
   */
  behavior: 'block';
}

Anchor to interceptorrequestallowInterceptorRequestAllow

Allow the buyer to proceed further in the checkout

Anchor to behavior behavior "allow" required: Indicates that the interceptor will allow the buyer's journey to continue.
Anchor to perform perform (result: ) => void | Promise<void>: 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.
```
"allow"
```

interface InterceptorResultAllow {
  /**
   * Indicates that the buyer was allowed to progress through checkout.
   */
  behavior: 'allow';
}

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.
```
"block"
```

interface InterceptorResultBlock {
  /**
   * 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.
   */
  behavior: 'block';
}

Examples

React

import {

reactExtension,

useBuyerJourneyIntercept,

useShippingAddress,

} from '@shopify/ui-extensions-react/checkout';

export default reactExtension(

'purchase.checkout.delivery-address.render-before',

() => <Extension />,

);

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;

}

Examples

Block progress and show error for a checkout UI field

Description

Intercept and prevent a buyer's progress through checkout while targeting a specific checkout UI field. See the [validation tutorial](/docs/apps/checkout/validation) for more examples and best practices.

React

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

export default reactExtension(
  'purchase.checkout.delivery-address.render-before',
  () => <Extension />,
);

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;
}

Block progress and show error at page level

Description

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.

React

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

export default reactExtension(
  'purchase.checkout.delivery-address.render-before',
  () => <Extension />,
);

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 in your extension

Description

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.

React

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

export default reactExtension(
  'purchase.checkout.cart-line-item.render-after',
  () => <Extension />,
);

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 ? (
    <Banner>
      This item has a limit of one per customer.
    </Banner>
  ) : null;
}