Counter Trait

The Counter trait provides a simple counter mechanism that can only be incremented or decremented by one. This can be useful for tracking the number of elements in a mapping, issuing NFT IDs, counting request IDs, and more.

Properties

• Counter: Int
  • Represents the current count. This variable should not be accessed directly by users of the library; interactions should be restricted to the library's functions.
  • Default Value: 0

Methods

• current() -> Int

  • A getter function that returns the current value of the counter.
  • Returns: Int
  • Example:

    let currentValue = self.current();

• increment()

  • Increments the counter value by one.
  • Example:

    self.increment();

• decrement()

  • Decrements the counter value by one.
  • Example:

    self.decrement();

Usage Example

To use the Counter trait in your smart contract, follow these steps:

1. Import the Counter Trait: Ensure that the Counter trait is imported into your contract file.

   import "../imports/tonion/utils/Counter.tact";

2. Create Your Contract: Extend your contract with the Counter trait. Implement the required methods and initialize the variables as needed.

   import "../imports/tonion/utils/Counter.tact";
   contract MyCounterContract with Counter {
       // Initialize the Counter
       init() {
           self.Counter = 0;
       }
   
       // Use the increment method
       receive("IncrementCounter") {
           self.increment();
       }
   
       // Use the decrement method
       receive("DecrementCounter") {
           self.decrement();
       }
   
       // Get the current counter value
       receive("GetCounter") {
           let currentValue: Int = self.current();
           // Send the current value back to the caller
       }
   }

In this example:

• The MyCounterContract contract uses the Counter trait to manage a counter.
• The init method initializes the counter to 0.
• The receive methods allow for incrementing, decrementing, and getting the current counter value through specific messages.
• The increment and decrement methods are used to modify the counter value.
• The current method is used to retrieve the current value of the counter.

By following these steps, you can integrate and use the Counter trait in your smart contracts to efficiently manage and track a simple counter.