How to publish page while using Platform.Variable.GetAttributeValue

Question

I am building a custom preference center in SFMC with SSJS that will pass the subscriber context into the landing page via the microSiteUrl() from an email. I am building and testing JUST the landing page portion. In my code I am using the Platform.Variable.GetAttributeValue('xxxxxxxxxx) to get the Subscriber Key, JobID and BatchID. I need these to log an unsub event.

When I go to publish (or even preview) the page I get an error. If I comment out the code, everything is fine. I know that technically the subscriber context isn't there because I'm not accessing the landing page via an email with microSiteUrl(). How can I get those 3 values (subscriberID, JobID and BatchID) and still publish the page?

This is my code:

<script runat="server">
    Platform.Load("core","1");

    /*subscriber context */
    var subscriberKey = Platform.Variable.GetAttributeValue('_subcriberkey');
    var batchid = Platform.Variable.GetAttributeValue('BatchID'); 
    var jobid = Platform.Variable.GetAttributeValue('JobID');`
</script> 

Answer 1

I usually set those variables in AMPscript, which still allows me to save the page even though there aren't any values.

%%[
SET @subscriberKey = _subscriberkey
SET @emailAddress = emailaddr 
SET @jobID = jobid 
SET @listID = listid 
SET @batchID = _JobSubscriberBatchID 
]%%

Then simple refer to them in SSJS using the following:

<script runat="server">
    Platform.Load("core", "1.1.1")
    var emailFields = {
        //NOTE: Retrieving AMPscript variables into SSJS if coming from email.
        subKey: Variable.GetValue("@subscriberKey"),
        emailAddress: Variable.GetValue("@emailAddress"),
        jobID: Variable.GetValue("@jobID"),
        listID: Variable.GetValue("@listID"),
        batchID: Variable.GetValue("@batchID")
    }
</script>

Answer 2

Use from either of the two options below to retrieve the _subscriberKey :

Core Function:

var SubscriberKey = Attribute.GetValue("_subscriberKey");

Platform Function:

var SubscriberKey = Platform.Recipient.GetAttributeValue("_subscriberKey");