GoCardless SDK Example App

The GoCardless Android SDK is a tool that enables developers to integrate GoCardless payments into their Android applications. To help developers get started, a sample app has been created that demonstrates how to use the SDK. The app provides a clear and practical example of how to implement GoCardless payments within an Android app.

Getting started

<dependency>
    <groupId>com.gocardless</groupId>
    <artifactId>gocardlesssdk</artifactId>
    <version>1.0.1</version>
</dependency>

With Gradle:

implementation 'com.gocardless:gocardlesssdk:1.0.0'

Initializing the client

The client is initialised with an access token, and is configured to use GoCardless' live environment by default:

import com.gocardless.gocardlesssdk.GoCardlessSDK
import com.gocardless.gocardlesssdk.network.Environment

GoCardlessSDK.initSDK(
    "YOUR_ACCESS_TOKEN",
    Environment.Live
)

Supported Services

Currently we support the following services and their functions

Billing Request

• createBillingRequest: Creates a Billing Request, enabling you to collect all types of GoCardless payments
• collectCustomerDetails: If the billing request has a pending collect_customer_details action, this endpoint can be used to collect the details in order to complete it.
• collectBankAccount: If the billing request has a pending collect_bank_account action, this endpoint can be used to collect the details in order to complete it.
• confirmPayerDetails: This is needed when you have a mandate request. As a scheme compliance rule we are required to allow the payer to crosscheck the details entered by them and confirm it.
• fulfil: If a billing request is ready to be fulfilled, call this endpoint to cause it to fulfil, executing the payment.
• cancel: Immediately cancels a billing request, causing all billing request flows to expire.
• notify: Notifies the customer linked to the billing request, asking them to authorise it.
• getBillingRequest: Fetches a billing request
• listBillingRequests: Returns a cursor-paginated list of your billing requests.

Billing Request Flow

• createBillingRequestFlow: Creates a new billing request flow.

Payment

• createPaymentRequest: Creates a new payment object.
• ``

Examples

Note: To be able to make any request, you must initialise the SDK.

Fetching List of Billing Requests

Ensure that all requests are made within the correct Scope before launching.

viewModelScope.launch {
    val response = GoCardlessSDK.billingRequestService.listBillingRequests()
}

The response can be of two types: ApiSuccess or ApiError.

• ApiSuccess.value Contains the result of the operation.
• ApiError.error Contains details of the encountered error.

when(response) {
    is ApiSuccess -> {
        _uiState.value = MainUiState.Success(response.value)
    }
    is ApiError -> {
        _uiState.value = MainUiState.Error("Couldn't fetch")
    }
}

Handling Errors

Whenever the API encounters an issue, it returns a GoCardlessError or its derivatives to provide more context about the error. Below are the types of errors you may encounter:

• AuthenticationError: Indicates an issue with authentication.
• GoCardlessInternalError: Denotes an internal error within the GoCardless system.
• InvalidApiUsageError: Occurs when the API is used incorrectly.
• InvalidStateError: Indicates an invalid state in the system.
• MalformedResponseError: Denotes an issue with the response received from the API.
• PermissionError: Occurs when the user does not have the necessary permissions.
• RateLimitError: Indicates that the rate limit for API requests has been exceeded.
• ValidationFailedError: Denotes a validation failure, usually with user input.

Compatibility

Language: Kotlin

Our SDK is built using Kotlin, a modern programming language for Android development.

Target SDK: 34 (Android 14) - Latest

Our SDK is optimized for the latest Android features, providing compatibility up to SDK version 34.

Minimum SDK: 28 (Android 9)

Our SDK supports a wide range of devices, ensuring compatibility with Android 9 (API level 28) and higher. We have achieved a coverage of 95% on devices with this minimum SDK version.

Libraries

Our SDK utilizes the following libraries to enhance its functionality:

• OkHttp: A robust HTTP client for Android, used for making network requests efficiently.
• Retrofit: A type-safe HTTP client for Android and Java, simplifying the process of consuming RESTful APIs.

Threading: Coroutines

We leverage coroutines for handling asynchronous operations within our SDK. This enables smoother and more intuitive concurrency management, making your app's development process more efficient.