metadata api : INVALID_SESSION_ID:

Question

To update a picklist value I'm referring to the metadataclass.cls

I'm calling a class method (as like in metadadataclass example) to update the picklist value via a trigger (class method set to @Future(callout=true)) which seems to work but in the log i get an error as below:

Web service callout failed: WebService returned a SOAP Fault: INVALID_SESSION_ID: Invalid Session ID found in SessionHeader: Illegal Session faultcode=sf:INVALID_SESSION_ID faultactor=

Please any help on to fix this error so that i would be able to update the picklist value for the picklist list (custom field)?

Answer 1

UserInfo.getSessionId() returns null in asynchronous contexts so you have to pass the session ID in when you call the future method:

public class PicklistUpdater {

    public static void updateInFuture() {
        updateInFuture(UserInfo.getSessionId());
    }

    @future(callout=true)
    private static void updateInFuture(String sessionId) {
        MetadataService.MetadataPort service = new MetadataService.MetadataPort();
        service.SessionHeader = new MetadataService.SessionHeader_element();
        service.SessionHeader.sessionId = sessionId;
        service ...
    }
}

Not sure how high the risk is of the session ID no longer being valid by the time the future executes.