How to prevent executing some method from running twice

Question

I have a static method named ABC in apex which is called multiple times from aura due to iteration.

So in ABC I have few methods which need to be called only once in the first iteration.

How can I prevent this inner methods from executing multiple times?

I tried with various approach but not working.

Answer 1

Rather than iterating in aura and making a single request for each iteration, it may be possible to refactor in order to make a single request in aura passing the iterable thing to a refactored ABC that takes the matching type of iterable, then in ABC you can make decisions based on whether or not this is the first iteration.

Clarification: Instead of this pattern:

items.forEach( ( item ) => helper.updateOnServer( item ) );

...

ABC( Item__c item ) {
   // call some methods
}

You should try to refactor so that you can do something like this:

helper.updateOnServer( items );

...

ABC( List<Item__c> items ) {
    Boolean firstPass = true;
    for ( Item__c item : items ) {
        if ( firstPass ) {
            // do some things once
            firstPass = false;
        }
        // do some other things all the time
    }
}

Answer 2

You might consider creating an @AuraEnabled method that calls the methods you only want to run once, and execute that first from LWC. Then you can exclude the one-off apex methods entirely from the iterated calls. You add an additional server call, yes, but with the benefit of greater code simplicity, maintainability, and elegance. Any performance degradation should be unnoticeable.

Example (your method ABC is runOnEachIteration here for clarity):

CHANGE

// LWC:
for (const item of items) {
    await runOnEachIteration();
}

// APEX:
@AuraEnabled
public static void runOnEachIteration() {
    if (/* try to figure out if it hasn't been run yet */) {
        doThisOnce();
        doThatOnce();
    }
    
    doThisForEach();
}

INTO

// LWC:
if (items.length > 0) {
    await runOnce();
    for (const item of items) {
        await runOnEachIteration();
    }
}

// APEX:
@AuraEnabled
public static void runOnce() {
    doThisOnce();
    doThatOnce();
}

@AuraEnabled
public static void runOnEachIteration() {
    doThisForEach();
}

Answer 3

This is called as Recursion.

In order to handle the recursive calls, we can use static boolean variable(s) and check its values, that is, you can use static Boolean variable with default value true and in the trigger/desired logic, before executing your code you can keep a check that the variable is true or not. Once you check make the variable as false, that will avoid the logic from being called again.

SF basic article to handle Recursion.

Another SF article that stresses best practices to avoid recursion.