Decrement by 1, return previous¶
Atomically decrements by one the current value and returns the previous value of the counter. It is possible that multiple concurrent client requests may receive the same previous value. This occurs since only the decrementing part of the logic is atomic, the retrieval of the value before it is decremented is not.
Method:¶
PUT
Endpoint URL¶
The xxxx.backendless.app is a subdomain assigned to your application. For more information see the Client-side Setup section of this documentation.
https://xxxx.backendless.app/api/counters/<counterName>/get/decrement
where:
| Argument | Description |
|---|---|
<counterName> |
name of the counter to decrement. |
Request headers¶
user-token: optional value obtained as a result of the login operation.
where:
| Argument | Description |
|---|---|
user-token |
Optional header. Contains a value returned by Backendless in a preceding user Login API call. The operation will be executed with the security policy associated currently logged in user. This means all permissions associated with the user and the roles assigned to the user will be enforced by Backendless. |
Request body¶
N/A
Response body¶
Numeric value - previous value of the counter
Example¶
Make sure to replace xxxx in the domain name in the sample request below to the one assigned to your application.
curl -X PUT \
https://xxxx.backendless.app/api/counters/mycounter/get/decrement
Codeless Reference¶
where:
| Argument | Description |
|---|---|
counter name |
Name of the counter whose value must be decremented. |
return previous value |
When this box is checked, the operation returns the previous value of the counter. |
Returns the previous value of the counter, while decrementing the value by 1.
Consider the following counter:
The example below decrements the value of the "CarsParkingLot" by 1. This operation returns 10, since the return previous value box is checked. To avoid confusion, the value was decremented by 1, even though the return value is 10.
The result of this operation will look as shown below after the Codeless logic runs, as you can see the value of the counter was decremented by 1.
