Method does not exist or incorrect signature on afterUpdate

Question

I use a framework of a trigger factory to set up all my triggers and handlers of those triggers. Earlier I got some great advice on how to separate my concerns better for the handler.

I use this block for afterUpdate:

public override void afterUpdate(Map<Id, SObject> oldMapGeneric, Map<Id, SObject> newMapGeneric){
    Map<Id, Revenue_Pipeline__c> oldMap = (Map<Id, Revenue_Pipeline__c>) oldMapGeneric;
    Map<Id, Revenue_Pipeline__c> newMap = (Map<Id, Revenue_Pipeline__c>) newMapGeneric;
    /*AFTER UPDATE METHODS START*/
    if(!isRecursive)
    {
        isRecursive = true;
        List<Revenue_Pipeline__c> filtered = Revenue_PipelineTriggerHandler.needsNewSchedule(newMap, oldMap);
        deleteSchedule(filtered);
        createRevSchedule(filtered); 
    }
    /*AFTER UPDATE METHODS END*/
}

This then references my query method:

public void needsNewSchedule(Map<Id, Revenue_Pipeline__c> newMap, Map<Id, Revenue_Pipeline__c> oldMap)
{
    List<Revenue_Pipeline__c> revPipeline = new List<Revenue_Pipeline__c>();
    // Check if the fields changed

    for(Revenue_Pipeline__c revPipe : newMap.values())
    {
        if(
            revPipe.Product_Start_Date__c       != oldMap.get(revPipe.Id).Product_Start_Date__c ||
            revPipe.Product_End_Date__c         != oldMap.get(revPipe.Id).Product_End_Date__c ||
            revPipe.Product_Price__c            != oldMap.get(revPipe.Id).Product_Price__c ||
            revPipe.Weighted_Product_Price__c   != oldMap.get(revPipe.Id).Weighted_Product_Price__c)
            {
                revPipeline.add(revPipe.Id);
            }
    }
}

My problem is I get an error on the line:

List<Revenue_Pipeline__c> filtered = SL_Revenue_PipelineTriggerHandler.needsNewSchedule(newMap, oldMap);

With

Method does not exist or incorrect signature: Revenue_PipelineTriggerHandler.needsNewSchedule(Map, Map)

I'm accepting the newmap and oldMap in the method why does it not compile?

Answer 1

Your method needs to be static if you want to call it as you do now.

Incorrect

public void staticMethod(...)

MyClass.staticMethod(...)

Correct

public static void staticMethod(...)

MyClass.staticMethod(...)

---

Or you can leave the method as is and call it from an instance:

Incorrect

public void instanceMethod(...)

MyClass.instanceMethod(...)

Correct

public void instanceMethod(...)

new MyClass().instanceMethod(...)

In this case, though, you don't have any stateful information so you should go with the first approach.