Overview

The SubstractPaymentsModule trait manages payment deductions for services within a subscription model. It includes time constants representing subscription intervals and a custom result type for operation outcomes.

Constants

• DAILY_EPOCH: Represents a daily interval for subscriptions.
• WEEKLY_EPOCH: Represents a weekly interval for subscriptions.
• MONTHLY_EPOCH: Represents a monthly interval for subscriptions.

Custom Result Type

• CustomScResult<T, E>
  • A custom result type used within the module, which can either be Ok(T) for successful operations or Err(E) for errors.

Functions

• is_err() -> bool
  • Checks if the result is an error.
• unsafe unwrap_unchecked() -> T
  • Unsafely unwraps the result, should only be used when it's guaranteed to be Ok.

Usage

• Constants DAILY_EPOCH, WEEKLY_EPOCH, and MONTHLY_EPOCH can be used to configure subscription intervals.
• The CustomScResult provides a safe way to handle errors across the contract's functions.

Methods:

• substract_payment(service_index: usize, user_id: AddressId)
  • deducts a payment for a specific service, considering eligibility, subscription type and token type
• substract_specific_token(user_id: AddressId, token_id: EgldOREsdtTokenIdentifier, amount: BigUint)
  • deducts a specific token from the user’s account, handling EGLD or ESDT tokens differently
• substract_any_token(user_id: AddressId)
  • tries to deduct any token payment from the user’s account by taking safe prices in consideration

Important Notes