Document Capture

In this section, you will find all the necessary information for using and integrating the Unico IDCloud SDK into your Flutter applications for document capture

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This guide has been designed to help you implement the Flutter SDK quickly and easily. Below, you will find a step-by-step process for the entire integration. After that, if you wish to customize the experience, be sure to check the Flutter Customization section.

Available Document Frames

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In this camera mode, there is a capture frame to assist the user in positioning the document correctly. Once the document is properly positioned, the user must click the button to take a photo of the document.

The SDK does not perform any validation of what is being captured.

In this camera mode, it is possible to capture the following documents:

• CPF: Capture the front of the CPF;

• CNH: Capture the open CNH;

• CNH Front: Capture the front of the CNH;

• CNH Back: Capture the back of the CNH;

• RG Front: Capture the front of the RG;

• RG Back: Capture the back of the RG;

• Others: Capture any other document.

Initializing the SDK

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To get started, create an instance of the builder (generated through the UnicoCheckBuilder interface), providing the relevant context and the implementation of the UnicoListener class as parameters.

The implementation of this class is straightforward and can be done with just a few lines of code. All you need to do is override the callback methods with the business logic of your application.

Dart

class _MyHomePageState extends State<MyHomePage> implements UnicoListener {

    late UnicoCheckBuilder _unicoCheck;

    /// Unico callbacks
      @override
      void onErrorUnico(UnicoError error) {}

      @override
      void onUserClosedCameraManually() {}

      @override
      void onSystemChangedTypeCameraTimeoutFaceInference() {}

      @override
      void onSystemClosedCameraTimeoutSession() {}

      /// Document callbacks
      @override
      void onSuccessDocument(ResultCamera resultCamera) { }

      @override
      void onErrorDocument(UnicoError error) { }

}

Implementing the callback functions

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Note that, as in the previous example, the implementation work of the UnicoListener class is largely about configuring the callback methods. Each method is called in a specific situation based on the SDK's response.

Override the methods exemplified above with your application’s business logic.

1

onErrorUnico(UnicoError error)

This method is invoked with a parameter of type ErrorBio that contains details about the error. Learn more about the ErrorBio type in the error handling section.

2

onUserClosedCameraManually()

EThis method is invoked whenever the user manually closes the camera, such as by clicking the "Back" button.

3

onSystemClosedCameraTimeoutSession()

This method is invoked once the maximum session time is reached (without capturing any image).

You can configure the session timeout in seconds using setTimeoutSession. The default and minimum timeout is 40 seconds.

4

onSystemChangedTypeCameraTimeoutFaceInference()

This method is invoked when the maximum time for face detection is reached without detection.

The maximum time is 13 seconds. The mode is then switched to manual capture to facilitate the user’s action.

All the above methods must be created as indicated in your project (even without any logic); otherwise, the project won’t compile successfully.

Implementing Listeners for Camera Events

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The implementation of these listener methods should be done through an instance of the iAcessoBioSelfie class.

The camera open method needs to know what to do when an image is successfully captured or when an error occurs during the process. The camera's behavior is informed through the deployment of listeners, which are invoked in both success and error scenarios.

By implementing the listeners, you can specify what happens in your app in the event of an error (e.g., the onErrorDocument method) or success (e.g., the onSuccessDocument method) during the image capture process.

onSucessDocument Method

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When successfully capturing an image, this method is invoked and returns an object of type ResultCamera, which is used later in the REST API requests:

public void onSuccessDocument(ResultCamera resultCamera) { }

The ResultCamera object returns two attributes: base64 and encrypted.

• The base64 attribute can be used if you want to display a preview of the image in your app.

• Both the encrypted and base64 attributes can be sent in the REST API calls of the by Client.

If it is necessary to convert the base64 string to a bitmap, the standard method does not work for Android. You need to perform a split at the comma (,) for it to function correctly. If you want to learn more, read the article: How to convert a Base64 string into a Bitmap image to show it in a ImageView?.

onErrorDocument Method

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If an error occurs during the image capture, this method is invoked and returns an object of typeUnicoError:

public void onErrorDocument(UnicoError error) { }

Learn more about the types of ErrorBio in the SDK's error handling section.

Preparing and Opening the Camera

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To open the camera, the openCameraDocument() method is used. This method is made available through the object generated by an instance of the UnicoCheck class.

This method accepts the following parameters:

• A JSON file containing the credentials, generated in the credentials configuration step.

• The listeners configured above.

• The type of document to be captured, which can be one of the following:

Parameter	Description
DocumentCameraTypes.CPF	Capture the front of the CPF
DocumentCameraTypes.CNH	Capture the open CNH
DocumentCameraTypes.CNH_FRENTE	Capture the front of the CNH
DocumentCameraTypes.CNH_VERSO	Capture the back of the CNH
DocumentCameraTypes.RG_FRENTE	Capture the front of the RG
DocumentCameraTypes.RG_VERSO	Capture the back of the RG RG
DocumentCameraTypes.OUTROS("descrição")	Capture any other document

If you need to capture a document for which there is no specific frame (e.g., RNE, among others), use the DocumentCameraTypes.OUTROS("descrição") frame, which will allow you to use a generic rectangular frame to guide any capture.

Example using the open CNH:

 _unicoCheck.build().openCameraDocument(
        jsonFileName: androidJsonFileName,
        documentType: DocumentType.CNH,
        listener: this);

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Making a POST Request to the Client API

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After capturing images, the next step is to send the generated base64 image from the SDK to the Client APIs.

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