Import Expo Modules

How to Use the CafSmartAuth Native Module in React Native

This detailed guide explains how to integrate the CafSmartAuth expo module into your Expo project using TypeScript. It includes creating a module and a custom hook to manage events and methods provided by the native SDK.

1. Create the CafSmartAuthBridgeModule.ts File

This file imports the expo module.

Example Implementation

import { NativeModule, requireNativeModule } from "expo";

import { CafSmartAuthBridgeModuleEvents } from "./CafSmartAuthBridgeModule.types";

declare class CafSmartAuthBridgeModule extends NativeModule<CafSmartAuthBridgeModuleEvents> {
  startSmartAuth(
    mfaToken: string,
    faceAuthToken: string,
    personId: string,
    policyId: string,
    jsonString: string
  ): Promise<void>;
  requestLocationPermissions(): Promise<void>;
}

// This call loads the native module object from the JSI.
export default requireNativeModule<CafSmartAuthBridgeModule>(
  "CafSmartAuthBridgeModule"
);

2. Create the useSmartAuth.ts Hook

This hook manages the events and state associated with the CafSmartAuth module.

Key Functions

• formattedOptions: Formats the settings sent to the native module into JSON format.

• useSmartAuth: Hook that:

  • Listens to events emitted by the native module.

  • Updates React state based on the events.

• startSmartAuth: Method to initiate authentication using the native module.

• requestLocationPermissions: Method to request location permissions from the user.

Example Implementation

import { useState, useEffect } from "react";

import CafSmartAuthBridgeModule, {
  CafSmartAuthSettings,
  CafSmartAuthResponse,
  CafSmartAuthSuccess,
  CafSmartAuthError,
  CafSmartAuthPending,
  CafSmartAuthCancel,
  CafSmartAuthLoading,
  CafSmartAuthLoaded,
} from "../";

let responseFormattedOptions: string = "";

const formattedOptions = (settings: CafSmartAuthSettings): string => {
  const formatToJSON = JSON.stringify({
    ...settings,
  });

  return formatToJSON;
};

const useSmartAuth = (settings?: CafSmartAuthSettings) => {
  const [response, setResponse] = useState<CafSmartAuthResponse>({
    success: {
      isAuthorized: false,
      attemptId: null,
      attestation: null,
    },
    error: null,
    cancelled: false,
    isLoading: false,
    pending: {
      isAuthorized: false,
      attestation: null,
    },
  });

  responseFormattedOptions = formattedOptions(settings!);

  useEffect(() => {
    CafSmartAuthBridgeModule.addListener(
      "CafSmartAuth_Success",
      (event: CafSmartAuthSuccess) => {
        setResponse({
          success: {
            isAuthorized: event.isAuthorized,
            attemptId: event.attemptId,
            attestation: event.attestation,
          },
          error: null,
          cancelled: false,
          isLoading: false,
          pending: {
            isAuthorized: false,
            attestation: null,
          },
        });
      }
    );

    CafSmartAuthBridgeModule.addListener(
      "CafSmartAuth_Error",
      (event: CafSmartAuthError) => {
        setResponse({
          success: {
            isAuthorized: false,
            attemptId: null,
            attestation: null,
          },
          error: event,
          cancelled: false,
          isLoading: false,
          pending: {
            isAuthorized: false,
            attestation: null,
          },
        });
      }
    );

    CafSmartAuthBridgeModule.addListener(
      "CafSmartAuth_Cancel",
      (event: CafSmartAuthCancel) => {
        setResponse({
          success: {
            isAuthorized: false,
            attemptId: null,
            attestation: null,
          },
          error: null,
          cancelled: event.isCancelled,
          isLoading: false,
          pending: {
            isAuthorized: false,
            attestation: null,
          },
        });
      }
    );

    CafSmartAuthBridgeModule.addListener(
      "CafSmartAuth_Pending",
      (event: CafSmartAuthPending) => {
        setResponse({
          success: {
            isAuthorized: false,
            attemptId: null,
            attestation: null,
          },
          error: null,
          cancelled: false,
          isLoading: false,
          pending: {
            isAuthorized: event.isAuthorized,
            attestation: event.attestation,
          },
        });
      }
    );

    CafSmartAuthBridgeModule.addListener(
      "CafSmartAuth_Loading",
      (event: CafSmartAuthLoading) => {
        setResponse({
          success: {
            isAuthorized: false,
            attemptId: null,
            attestation: null,
          },
          error: null,
          cancelled: false,
          isLoading: event.isLoading,
          pending: {
            isAuthorized: false,
            attestation: null,
          },
        });
      }
    );

    CafSmartAuthBridgeModule.addListener(
      "CafSmartAuth_Loaded",
      (event: CafSmartAuthLoaded) => {
        setResponse({
          success: {
            isAuthorized: false,
            attemptId: null,
            attestation: null,
          },
          error: null,
          cancelled: false,
          isLoading: event.isLoaded,
          pending: {
            isAuthorized: false,
            attestation: null,
          },
        });
      }
    );

    return () => {
      CafSmartAuthBridgeModule.removeAllListeners("CafSmartAuth_Success");
      CafSmartAuthBridgeModule.removeAllListeners("CafSmartAuth_Pending");
      CafSmartAuthBridgeModule.removeAllListeners("CafSmartAuth_Error");
      CafSmartAuthBridgeModule.removeAllListeners("CafSmartAuth_Cancel");
      CafSmartAuthBridgeModule.removeAllListeners("CafSmartAuth_Loading");
      CafSmartAuthBridgeModule.removeAllListeners("CafSmartAuth_Loaded");
    };
  }, []);

  return {
    success: response.success,
    error: response.error,
    cancelled: response.cancelled,
    pending: response.pending,
    isLoading: response.isLoading,
  };
};

const startSmartAuth = (
  mfaToken: string,
  faceAuthToken: string,
  policyId: string,
  personId: string
) => {
  CafSmartAuthBridgeModule.startSmartAuth(
    mfaToken,
    faceAuthToken,
    personId,
    policyId,
    responseFormattedOptions
  );
};

const requestLocationPermissions = async () => {
  await CafSmartAuthBridgeModule.requestLocationPermissions();
};

export { startSmartAuth, requestLocationPermissions, useSmartAuth };

3. Available Methods

• useSmartAuth: A hook that provides the following states:

  • success: Information about successful authentications.

  • error: Details about errors that occurred.

  • cancelled: Indicates if the operation was cancelled.

  • pending: Information about pending authentications.

  • isLoading: Indicates if authentication is in progress.

• startSmartAuth: Method to start the authentication process.

  • Parameters:

    • mfaToken: Multi-factor authentication token.

    • faceAuthToken: Token for facial authentication.

    • policyId: ID of the authentication policy.

    • personId: ID of the person to authenticate.

• requestLocationPermissions: Method to request location permissions from the user (Android only).

4. Project Integration

Here is how to implement the hook in your project, follow SourceCode