How to use proration mode in app subscription android

Question

I using two subscription plans monthly and yearly in my android app. If a user has subscribed monthly plan then I want to give the user an option to upgrade to a yearly plan. I have read an official document I need to use BillingFlowParams.ProrationMode but I am unable to figure out how should I implement this.

Here is the code sample:

BillingFlowParams flowParams = BillingFlowParams.newBuilder()
        .setSkuDetails(skuDetails)
        .setOldSku(oldSku)
        // I need to replace replaceSkusProrationMode to DEFERRED
        // how do I get complete path to DEFERRED
        .setReplaceSkusProrationMode(replaceSkusProrationMode)
        .build()
int responseCode = billingClient.launchBillingFlow(activity, flowParams);

using this link I get the int value for DEFERRED is 4 but it's not a good idea to use hardcoded value.

How should I achieve this?

Answer 1

I was using an older version of billingclient upgrade to newer version solved my problem.

I changed to

implementation 'com.android.billingclient:billing:2.0.2'

From

implementation 'com.android.billingclient:billing:1.0'

then I get an option for setReplaceSkusProrationMode.

Here how I am using now:

BillingFlowParams flowParams1 = BillingFlowParams.newBuilder()
                        .setOldSku(monthly_test)
                        .setReplaceSkusProrationMode(BillingFlowParams.ProrationMode.DEFERRED)
                        .setSkuDetails(yearly_test)
                        .build();