[SalesForce] Cant catch exception and log to custom object if I throw exception

Background: I have worked w/ a consultant to build an Apex rest endpoint, and its working well.

Now I am adding some basic error handling, by putting the insert / update statements into try/catch blocks. If there is an exception, I would like to log it to a custom object. I have a simple utility class that can take an exception and a few optional parameters and it will do the logging.

Question: I've been flummoxed because the error log records are not being created if I throw the exception. Looking in the debug logs I can see that the writetoLog method is being called, and that it rolls back due to a fatal error, which has me thinking that throwing the exception results in the entire transaction being rolled back, including the logging, which I validated on another post on StackExchange.

I found one article on developer.force.com that suggested using a future method to handle the logging – would that address this issue?

I have a hunch that throwing a custom exception might be another alternative, but dont know if that is in fact the case.

So my question is: what are the simplest ways to catch the exception, log it to a custom object, and throw an exception (as else the transaction returns as a success, instead of an error).

The code is below. If I comment out throw e and instead return a string of the error message, the error log is created successfully, so I know there are no underlying permissions issues.

@HttpPost
global static string CreateContact(WebContactData wcd){              
    WebContact__c  wc = TranslateToInternalModel(wcd);
    try{
        Insert wc;
        return wc.Id;
    }catch(exception e){
       utils_logging.writeToLog(e, wcd.FormType, JSON.serializePretty(wcd));
       throw e; 
    }   
}

Best Answer

Unfortunately if your ending point in the code is throwing an error ALL of the transaction gets rolled back including your log creation. This creates quite the issue.

Future methods also get canceled.

IIRC you CAN make a callout to another restful endpoint that will persist a log entry as long as you have not done DML prior which in unlikely.

What you can do is this though, return a custom response object that the external system can use to determine if there is an error or not. Catch all errors and set the appropriate values in the response object. Modify as needed

@HttpPost
global static myResponse CreateContact(WebContactData wcd){ 
    WebContact__c  wc = TranslateToInternalModel(wcd);
    myResponse res = New MyResponse();
    try{
        Insert wc;
        res.result = wc.id;
        res.isError = false;
    }catch(exception e){
       utils_logging.writeToLog(e, wcd.FormType, JSON.serializePretty(wcd));
       res.isError = true;
    }   
        return res;

}

public class myResponse{
     public boolean isError {get;set;}
     public string result {get;set;}

     public myResponse(){       
     }
}

Related Solutions

[SalesForce] throw an exception in apex and still log the caught exception

First please take a look at this answer for a partial solution / approach, Can I prevent an insert to be rolled back even if my class (later) runs into an exception?.

Basically as per the Apex Developers guide the final commit transaction management is baked into Apex, meaning it will always rollback if you let the platform handle your exceptions, if you don't you have to manage the rollback scope yourself or accept any DML that has been issued be committed.

If the entire request completes successfully, all changes are committed to the database. For example, suppose a Visualforce page called an Apex controller, which in turn called an additional Apex class. Only when all the Apex code has finished running and the Visualforce page has finished running, are the changes committed to the database. If the request does not complete successfully, all database changes are rolled back

The only way to get control of this is to use the try/catch/finally semantics, along with Savepoints, and critically not throwing any exception (note that as per the answer above some system exceptions cannot be caught sadly). Since your implementing the Auth.RegistrationHandler interface your stuck with its method signature and thus cannot code any alternative way to pass errors back, not does there appear to be any support for this on the interface itself.

Passing a null user back from createUser. What happens if you using try/catch/finally with a logging approach as above and then null back? I expect the system will handle this and present some general error message. Of course in this case your more detail errors will have been logged, since technically the call completed successfully. You would of course have to educate your users / admins to check your own log in this case. Given the frequency of the issues, perhaps this is tolerable? As regards the updateUser method, i don't see any way to infer errors with a successful execution of the method.

Summary and System.debug? Sorry this is not the answer you wanted, but i believe this is the situation. Your not the first to want to implement such a logging approach as you can see. Ultimately its a matter of how far your prepared to go against the transaction management semantics of the platform vs resorting to having your Admins enable Debug Logs and adding System.debug output to your code to output messages to the standard platform log that can then be reviewed for your errors.

[SalesForce] Throw error message and capture it in error log custom object

You can now do this by way of Platform Events. Unlike normal DML operations, Platform Events are not rolled back in a transaction, even if there are failures. To use this feature, there's a few steps involved.

First, create your Log object, if you haven't already. Next, create a Platform Event that has a field (or more, if you desire). After that, add a trigger to actually create the logs. Here's an example:

// Note: __e is not a typo. It is the special extension used by Platform Events.
trigger LogErrorEventTrigger on LogErrorEvent__e (after insert) {
    Log__c[] logs = new Log__c[0];
    for(LogErrorEvent__e record: Trigger.new) {
        logs.add(new Log__c(Log__c=record.Log__c));
    }
    insert logs;
}

To actually use this, you need to "publish" these events:

trigger CustomObjectTrigger on CustomObject__c (after insert) {
    LogErrorEvent__e[] logs = new LogErrorEvent__e[0];
    for(CustomObject__c record: Trigger.new) {
        logs.add(new LogErrorEvent__e(Log__c='Blocked insert'));
        record.addError('Block insert');
    }
    EventBus.publish(logs);
}

This will prevent inserts, updates, deletes, undeletes, whichever you would like to handle, and log the appropriate message into your log queue.

Best Answer

Related Solutions

[SalesForce] throw an exception in apex and still log the caught exception

[SalesForce] Throw error message and capture it in error log custom object

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