> For the complete documentation index, see [llms.txt](https://docs.caf.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.caf.io/caf-sdk/android/standalone-modules/document-detector/source-code.md).

# Source Code

```kotlin
class MainActivity : AppCompatActivity() {
    private lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.startDocumentDetectorButton.setOnClickListener {
            startDocumentDetector()
        }
    }

    private fun startDocumentDetector(upload: Boolean = false) {
        val documentDetector = buildDocumentDetector(upload)
        val intent = Intent(this, DocumentDetectorActivity::class.java)
        intent.putExtra(DocumentDetector.PARAMETER_NAME, documentDetector)
        startActivityForResult(intent, REQUEST_CODE)
    }

    private fun buildDocumentDetector(upload: Boolean = false): DocumentDetector? =
        DocumentDetector.Builder("eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiI2NTRjZmFlMWM5YTM0NTAwMDg4YzIwODUifQ.maH9fynasnaRR2Hm5PxQ1XzLxlVZiZSvpVDD9zVtfgs")
            .setDocumentCaptureFlow(
                arrayOf(
                    DocumentDetectorStep(Document.CNH_FRONT),
                    DocumentDetectorStep(Document.CNH_BACK),
                )
            )
            .setUploadSettings(
                UploadSettings(upload)
            )
            .setPersonId("12312312312")
            .setUseDeveloperMode(true)
            .setUseAdb(true)
            .setUseDebug(true)
            .build()

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
            val result = data?.getSerializableExtra(
                DocumentDetectorResult.PARAMETER_NAME
            ) as DocumentDetectorResult

            if (!result.wasSuccessful()) {
                result.sdkFailure?.let {
                    onSdkFailure(it)
                }
                return
            }

            println("DocumentDetectorResult: $result")
        } else {
            println("The user canceled the operation")
        }
        super.onActivityResult(requestCode, resultCode, data)
    }

    private fun onSdkFailure(sdkFailure: SDKFailure?) {
        when (sdkFailure) {
            is InvalidTokenReason -> {
                println("SDKFailure: The token entered as a parameter is not valid, please revise it")
            }
            is PermissionReason -> {
                println("SDKFailure: The user did not grant the necessary permissions")
            }
            is AvailabilityReason -> {
                println("SDKFailure: Instructions are sent in: ${sdkFailure.message}")
            }
            is NetworkReason -> {
                println("SDKFailure: There was a problem with the internet connection")
            }
            is ServerReason -> {
                println("SDKFailure: There was a problem in any communication with the CAF servers, let us know!")
            }
            is SecurityReason -> {
                println("SDKFailure: There was a security problem on the user's device")
            }
            is StorageReason -> {
                println("SDKFailure: There was a problem with the internal storage of the user's device")
            }
            is LibraryReason -> {
                println("SDKFailure: There was a problem with the internal library")
            }
            else -> {
                println("SDKFailure: Unknown reason")
            }
        }
    }

    companion object {
        private const val REQUEST_CODE = 123456
    }
}
```


---

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