Invoke Apex With No Invocable Method From Workflow Rule or Process Builder

Question

I'm looking for a way to fire an Apex Class without using code or a button click. My Apex Class does not have an invocable method so I can't fire it using the standard Process Builder. But I do have a button set up which fires the class at the moment, with the following code:

{!REQUIRESCRIPT("/soap/ajax/10.0/connection.js")} 
{!REQUIRESCRIPT("/soap/ajax/10.0/apex.js")}

if ( '{!Opportunity.Record_Type_Name__c}' == 'CP_Disbursement' ) {    
    var result = sforce.apex.execute(
        "CP_MonthlyRevenueForecastDisbursement",
        "createMonthlyForecastRecordsDisbursement",
        {opportunityId:'{!Opportunity.Id}'}
    );
    if ( result == 'Success' ) {
        window.location.href=window.location.href;
    } else {
        alert(result);
    }
} else {
    var result = sforce.apex.execute(
        "CP_MonthlyRevenueForecastController",
        "createMonthlyForecastRecords",
        {opportunityId:'{!Opportunity.Id}'}
    );
    if ( result == 'Success' ) {
        window.location.href=window.location.href;
    } else {
        alert(result);
    }
}

Is it possible to imitate a button click using a workflow rule or the process builder? Is there another way to invoke the Apex Class without code?

Or, as a last resort, is the process of making the method invocable as simple as adding @InvocableMethod(label='xyz') to the code - as long as the method already complies with the rules listed in the developer guide?

Developer Guide - InvocableVariable Annotation

Answer 1

U can use visual flow to call it. Try to invoke a flow from button and the flow in turn calls the apex.

http://lc169.blogspot.in/2013/08/calling-apex-class-from-visual-flow.html

HTH Prabhan

Answer 2

@Alex: As I understand, you want to invoke a piece of functionality (apex code) when certain fields on Opportunity are updated. If this is correct, then you can use Apex Triggers to achieve the same.

An Apex Triggers is apex code, which is invoked by Force.com whenever any DML operation is being performed on an entity (insert, delete, update etc.). Refer https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_qs_trigger.htm for more information