@trulioo/docv-capture-web

Trulioo DocVCapture Web SDK

Document Capture and Verification Flow Overview

Starting a new document verification transaction

Create an instance of TruliooCapture and call the initialize function using the shortcode obtained from the Trulioo API endpoint: /customer/handoff. This will create a new document verification transaction with a unique Transaction ID.

const shortCode = "generatedFromTruliooAPI"

const truliooCapture = new TruliooCapture()

truliooCapture.initialize(shortCode).then((transactionId) => {
    console.log(`Successfully initialized with transaction ID: ${transactionId}`)
}).catch(error => {
    console.log(`Error on initialize: ${error}`)
})

Creating and rendering a camera component

Using the same created instance of TruliooCapture, we can get a camera component to be rendered later by calling the getCameraComponent function. We can specify the camera detection type by providing a TruliooCameraConfig with the desired DetectionType.

// Will get a document detection type camera by default.
const documentCamera = truliooCapture.getCameraComponent()


// To get a selfie detection type camera.
const selfieCamera = truliooCapture.getCameraComponent({
  detectionType: DetectionType.BIOMETRIC_SELFIE,
})

To render the camera component on the screen, we just need to call the renderCamera function. This will render a full screen camera on the screen by attaching a video element to the parent element based on the provided element id. The renderCamera function will resolve when the camera is successfully loaded, otherwise it will reject with an error. The onCaptureRegionChange callback function is provided, which will return the current capture frame coordinates location (the location on the camera screen where the document/face should be located to do a capture). We can utilize this coordinate information to render a custom UI overlay.

const cameraProps = new CameraProps(
    (captureRegion: CaptureRegion) => {
        // Utilize the given captureRegion data to render custom UI.
    }
)

documentCamera.renderCamera("parent-element-id", cameraProps).then((_) => {
    console.log("Camera is successfully loaded")
}).catch((e: Error) => {
    console.error(`Camera is not loaded successfully: ${e.message}`)
})

To remove the current camera on the screen, call the removeCamera function.

documentCamera.removeCamera()

Additionally, if we want to resume the camera feed again after a successful auto or manual capture, we can call the resumeCamera function.

documentCamera.resumeCamera()

Starting the document capture flow

Once the camera component is loaded and ready, we can start the document capture experience by calling startFeedback from previously created TruliooCapture instance.

To do an auto capture experience (a good document/selfie image criteria decided entirely by SDK), we can simply call startFeedback by just providing the camera id that refers to the currently active/rendered camera component. The promise will only resolve when the SDK manages to capture a good image that is presented in front of the camera capture frame.

truliooCapture.startFeedback(documentCamera.id).then((result: TruliooCaptureResponse) => {
    console.log(`Successfully captured a good image with imageId: ${result.imageId}`)
})

We can also stop the feedback by calling the stopFeedback function. This will stop any ongoing feedback from the camera component.

truliooCapture.stopFeedback(documentCamera.id)

Note that if the stopFeedback function is called during an ongoing startFeedback promise, the startFeedback promise is expected to be rejected with the specific FeedbackStopped error. It is recommended to check this specific error to make sure it is not treated as an unexpected error.

import { HandledError } from '@trulioo/docv-capture-web'

truliooCapture.startFeedback(documentCamera.id).then((result: TruliooCaptureResponse) => {
    console.log(`Successfully captured a good image with imageId: ${result.imageId}`)
}).catch((error: unknown) => {
    if (error == HandledError.FeedbackStopped) {
        console.log("startFeedback was stopped.")
    } else {
        // Other error handling
    }
})

Additionally, if we want to do a manual capture instead. We can call the captureLatestFrame function. This will return a TruliooManualCaptureResponse that is similar to the TruliooCaptureResponse excluding the auto capture specific fields. Note that we would want to make sure the camera feed is currently running before triggering the manual capture, hence we can resume the camera again after a successful auto or manual capture using the resumeCamera function if we want to trigger another capture.

truliooCapture.captureLatestFrame(documentCamera.id).then((result: TruliooManualCaptureResponse) => {
    console.log(`Successfully captured an image manually with imageId: ${result.imageId}`)
})

The SDK also provides the onFeedbackState function that we can listen to for the ongoing capture state updates that is started by the startFeedback function. This allows us to add any logic needed or render any necessary custom UI needed based on the current capture state. It is recommended to call the onFeedbackState function and start listening to the feedback state before calling the startFeedback function.

truliooCapture.onFeedbackState(
    (feedbackState: FeedbackState) => {
        switch (feedbackState) {
            case FeedbackState.NONE:
                // Nothing happened yet/no document detected at this point.
                break
            case FeedbackState.CAPTURING:
                // Currently in the middle of capturing a document.
                break
            case FeedbackState.BLUR:
                // The detected document is blurry. Show a blur UI feedback to user.
                break
            case FeedbackState.SUCCESS:
                // Managed to capture a document.
                break
            default:
                break
        }
    },
)

Note that the above flow is the same for the selfie capture type too.

Analyzing the captured image result through post capture verify feedback

Once we have the resulting TruliooCaptureResponse or TruliooManualCaptureResponse image data, we are able to get a post capture feedback by simply calling the verifyImage function that is part of the response data. This will give us more information regarding the captured image and let us decide whether we should submit the captured image for verification by calling the acceptImage function.

// As an example, we will submit the captured image for document verification if the post capture feedback documentVerifyResponse.documentTypeAccepted is not RESULT_CHECK_DECLINED.
// Note that the documentVerifyResponse will have more than just documentTypeAccepted, the below code is just an example of just checking for documentTypeAccepted.
result.verifyImage().then((verifyFeedback: TruliooVerifyFeedback) => {
    if (verifyFeedback.documentVerifyResponse.documentTypeAccepted !== ResultCheck.RESULT_CHECK_DECLINED) {
        // Note that the acceptImage can be called outside of the verifyImage function.
        result.acceptImage().then((status: boolean) => {
            console.log("Successfully submitted the image.")
        })
    } else {
        // Do something else, e.g., notify the user about the not accepted image and retake a new image.
    }
})

Finalize the document verification transaction

Once we submitted all the necessary images for the transaction, we can finalize the transaction by calling the submitTransaction function.

truliooCapture.submitTransaction().then((status: boolean) => {
    console.log("Transaction successfully submitted.")
})