Document Capture

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

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.

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

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.

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

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.

Implementing Listeners for Camera Events

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

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.

onErrorDocument Method

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

public void onErrorDocument(UnicoError error) { }

Preparing and Opening the Camera

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:

Example using the open CNH:

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

Making a POST Request to the Client API

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

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