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How to Set Up Cross-Platform, Multi-Type Atomic Counters

by on September 1, 2019

There are plenty of use cases when mBaaS-powered applications must use a centralized mechanism for incrementing or decrementing a value. There are several approaches for maintaining a counter – some apps use a database, others keep it in the server-side business logic (Cloud Code).

Backendless offers a specialized API for working with atomic counters. The API is cross-platform – any number of different clients (including REST) can work with the same counter and update it concurrently. Every counter in Backendless has a name, which is assigned by the client application. The sample below demonstrates the API for incrementing and retrieving the value of a counter.

    
    

    
    

    id counter = [Backendless.shared.counters ofCounterName:@"my counter"];
    [counter incrementAndGetWithResponseHandler:^(NSInteger counterValue) {
        NSLog(@"Counter value - %li", (long)counterValue);
    } errorHandler:^(Fault *fault) {
        NSLog(@"Error: %@", fault.message);
    }];

    let counter = Backendless.shared.counters.of(counterName: "my counter")
    counter.incrementAndGet(responseHandler: { counterValue in
        print("Counter value - \(counterValue)")
    }, errorHandler: { fault in
        print("Error: \(fault.message ?? "")")
    })

    const counter = Backendless.Counters.of('my counter')
    
    counter.incrementAndGet()
      .then(counterValue => {
        console.log(`Counter value - ${ counterValue }`)
      })
      .catch(error => {
        console.error(`Server reported an error - ${ error.message }`)
      })
    

    
    

    The API is very easy to use and provides several other features like decrementing a value, performing a conditional update, retrieving the current value, and resetting a counter.

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