Carbon Calculator SDK

Version 1.0.5

Table of Contents

1. Carbon Calculator SDK Overview

   1.1. What is Carbon Calculator SDK?

   1.2. How Carbon Calculator SDK works?

   1.3. Versioning and backward compatibility

2. Technical overview

   2.1. Basic information

   2.2. Basic configuration

   2.3. Carbon Calculator SDK Setup

   2.4. Error handling

3. Carbon Calculator Service

   3.1. getTransactionsFootprints

4. Document changelog

   4.1 Version 1.0.0

   4.2 Version 1.0.2

   4.3 Version 1.0.3

   4.4 Version 1.0.4

   4.5 Version 1.0.5

1. Carbon Calculator SDK Overview

1.1. What is Carbon Calculator SDK?

The Carbon Calculator SDK is a module dedicated for previewing the estimated carbon footprint of transactions.

1.2. How Carbon Calculator SDK works?

In order to incorporate this SDK into your app, see Basic configuration

1.3. Versioning and backward compatibility

SDK is based on semantic versioning.
For example: 1.0.0 ( MAJOR.MINOR.PATCH )

• Major version compatibility-breaking changes in SDK public APIs.
  It is mandatory to update application code, to use SDK, when this is incremented.
• Minor version tracks new, not compatibility-breaking changes in public API of SDK.
  It is optional to update application code, when this digit is incremented.
• Patch version tracks internal changes in SDK.
  No updates in application code are necessary to update to version, which has this number incremented.

Changes not breaking compatibility:

• adding new optional interface to SDK setup
• adding new method to any domain
• adding new enum value to input or output
• adding new field in input or output model

2. Technical overview

This section describes basic information about Carbon Calculator SDK setup and available methods.

2.1. Basic information

2.1.1 Facade

Facade is entry point to communication with Carbon Calculator SDK.

2.1.2 Multiple facade types

Carbon Calculator SDK provides two public API's with same functionalities, the API's are:

• CarbonCalculatorCoroutineService for projects which uses Kotlin programming language and Coroutines.
• CarbonCalculatorStdService for projects which uses Kotlin or Java programming language and standard Callback.

The difference between the API's is a way of providing data to SDK methods and getting the results from them.
Input and output as an data models are the same.
This documentation presents I/O types in a Kotlin way as it's easier to mark nullable fields (as question mark).

2.1.3 Method structure

Every method description has same structure.

Execution type:

• Asynchronous - operation could take more time and method is called on thread different than main.
  The result of execution is provided in callback (described below).
• Synchronous - result of operation is provided as method return type.

Method type:

• Online - operation requires Internet connection.
• Offline - operation can be called without Internet connection.

Input
Input parameters with name, type and description.

Output
Result delivered by standard Callback with data or result is suspended until the Coroutine completes <Multiple facade types>.

2.2 Basic configuration

2.2.1 Min SDK Version

The minSdkVersion must be at least 23 (Android 6.0).

2.2.2 Artifactory

SDK is available on Verestro maven repository and can be configured in project using Gradle build system.

Username and password are provided by Verestro.

repositories {  
    maven { 
        credentials { 
            username "<enter_username_here>" 
            password "<enter_password_here>" 
        } 
         url "https://artifactory.upaid.pl/artifactory/libs-release-local/"
    }
}  

2.2.3 SDKs version

Carbon Calculator SDK is available in two versions: debug and release.
The difference between version is debug allows to use application with debugger connected.
Debug version is ended with appendix "-debug" in version name.
Samples below.

For release version, used on production environment in application uploaded to Google Play:

dependencies {  
    implementation 'com.verestro.sdk:carbon-calculator:{version}'
}  

For debugging purposes:

dependencies {  
    implementation 'com.verestro.sdk:carbon-calculator-dev:{version}-debug'
}  

2.2.1 Source code obfuscation and optimization

As SDK is written in Kotlin language we recommend to add following code to gradle configuration:

android {  
... 
     kotlinOptions { 
         freeCompilerArgs = [ 
             '-Xno-param-assertions', 
             '-Xno-call-assertions', 
             '-Xno-receiver-assertions' 
        ] 
    }  
    packagingOptions { exclude '/kotlin_metadata/**' } 
...
}  

Then use newest tools for code shrinking, optimization and obfuscation from Google by enabling R8 instead Proguard in gradle.properties file:

android.enableR8=true  

2.3 Carbon Calculator SDK Setup

Available configuration methods:

• CarbonCalculatorCoroutineApi.init(configuration: Configuration)
• CarbonCalculatorStdApi.init(configuration: Configuration)

2.3.1 Input

2.3.2 Sample

CarbonCalculatorCoroutineApi

fun init(configuration: Configuration) {  
    CarbonCalculatorCoroutineApi.init(configuration)
}  

CarbonCalculatorStdApi

fun init(configuration: Configuration) {  
    CarbonCalculatorStdApi.init(configuration)
}  

2.4 Error handling

SDK returns errors by CarbonCalculatorException, which could be catched by application and shown on UI with detailed message.
Table below describes general exception types.

CarbonCalculatorException

3 Carbon Calculator Service

3.1 getTransactionsFootprints

Asynchronous. Online.  

This method obtains carbon footprint for given transactions.  

3.1.1 Input

GetTransactionsFootprintsData

TransactionModel

AmountModel

CardType

3.1.2 Output

3.1.2.1 Success

Success callback with GetTransactionsFootprintsResult model.  

GetTransactionsFootprintsResult

TransactionModel

CardType (deprecated)

CardTypeValue

3.1.2.2 Failure

Failure callback with throwable.  

3.1.3 Sample

Standard Callback

fun getTransactionsFootprints(getTransactionsFootprintsData: GetTransactionsFootprintsData) {  
    CarbonCalculatorCoroutineApi
        .carbonCalculatorStdService
        .getTransactionsFootprints(
            getTransactionsFootprintsData = getTransactionsFootprintsData, 
            callback = object : ApiCallback<GetTransactionsFootprintsData> { 
                override fun onSuccess(response: GetTransactionsFootprintsData) { // handle success }
                override fun onFailure(error: Throwable) { // handle error }
            } 
        )
}  

Kotlin Coroutines

suspend fun getTransactionsFootprints(  
    getTransactionsFootprintsData: GetTransactionsFootprintsData  
): GetTransactionsFootprintsResult =  
    CarbonCalculatorCoroutineApi  
        .carbonCalculatorCoroutineService  
        .getTransactionsFootprints(getTransactionsFootprintsData = getTransactionsFootprintsData) 

4. Document changelog

4.1. Version 1.0.0

• Created Carbon Calculator SDK

4.2. Version 1.0.2

• Added new type of exception - TransactionsLimitExceededException

4.3. Version 1.0.3

• Disables pinning and obfuscation for debug

4.4. Version 1.0.4

• Updated koin to version 3.5.3
• Updated java to 17
• Updated compile and target android version

4.5. Version 1.0.5

• Marked cardType field in SDK result model with @Deprecated.
• Added corresponding value class field cardTypeValue for deprecated field.