Trailhead : Variable Scope Issue (Compiler Error)

Question

This is my class

global class ProjectCalloutService1  {

String OppId;

@InvocableMethod
public static void postOpportunityToPMS(List<Id> oids)
{

     OppId = oids[0];

}

global class QueueablePMSCall implements Queueable, Database.AllowsCallouts
{
   public void execute(QueueableContext context)
   {

    Opportunity o = [SELECT ID,Name,Account.Name,CloseDate,Amount FROM Opportunity WHERE Id = '1'];

    ServiceTokens__c s = ServiceTokens__c.getValues('ProjectServiceToken');
    System.debug(s.Token__c);

    String jsonInput = '{\n' +
    ' "opportunityId" : "'+o.Id+'",\n'+
    ' "opportunityName" : "'+o.Name+'",\n'+
    ' "accountName" : "'+o.Account.Name+'",\n'+
    ' "closeDate" : "'+String.ValueOf(o.CloseDate).mid(0,10)+'",\n'+   
    ' "amount" : '+o.Amount+'\n'+
    '}';

    HTTPRequest req = new HTTPRequest();
    req.setEndPoint('callout:ProjectService');
    req.setMethod('POST');
    req.setHeader('Content-Type', 'application/json');
    req.setHeader('Token', s.Token__c);
    req.setBody(jsonInput);

    HTTP h = new HTTP();
    HTTPResponse res = h.send(req);
    System.debug('~~~ REQ BODY '+req.getBody());
    System.debug('~~~ REQUEST '+req.toString());
    System.debug('~~~ RESPONSE '+res);

    if(res.getStatusCode() == 201)
    {
      o.Type = 'Submitted Project';
      update o;
    }

   }

} 


}

I still have not finished developing this class so kindly excuse if it does not make sense.

My concern is with respect to compiler error that I am getting which says below

Error: Compile Error: Variable does not exist: OppId at line 9 column 6

I have tried adding global and public access modifiers in front of "String OppId" without success.

I thought as per OO principles a member variable can be accessed by all member methods within the same class.

When that being the case why my method "postOpportunityToPMS" complains that the variable "OppId" does not exist ?

Answer 1

You are trying to reference instance variable inside a static method, which is not allowed.

This is Instance variable:

String OppId;

This is static variable:(this variable now can be used in static methods.)

Static String OppId;