Skip to content

Conditional update

Atomically sets the value to the given updated value if the current value == the expected value.

// *******************************************
// Backendless.Counters approach
// *******************************************
Backendless.Counters.compareAndSet( counterName, expected, updated )
 .then( function( result ) {
 })
 .catch( function( error ) {
 });

// *******************************************
// Backendless.Counters.of() approach
// *******************************************
var counter = Backendless.Counters.of( counterName );
counter.compareAndSet( expected, updated )
 .then( function( result ) {
 })
 .catch( function( error ) {
 });

where:

Argument                Description
counterName name of the counter to update.
expected the expected value of the counter. If the current value equals the expected value, the counter is set to the "updated" value.
updated the new value to assign to the counter if the current value equals the expected value.

Example

var successCallback = function( response ) {
  console.log( "has the counter been updated? - " + response );
};

var failureCallback = function( fault ) {
  console.log( "error - " + fault.message );
};

// ************************************************
// Backendless.Counters approach
// ************************************************
Backendless.Counters.compareAndSet( "my counter", 1000, 2000 )
 .then( successCallback )
 .catch( failureCallback );

// ************************************************
// Backendless.Counters.of() approach
// ************************************************
var myCounter = Backendless.Counters.of( "my counter" );

myCounter.compareAndSet( 1000, 2000 )
 .then( successCallback )
 .catch( failureCallback );