hasValue() verses nil()

gflewis
Kilo Expert

‎01-15-2011 12:31 AM 


hasValue()
and 

nil()
appear to serve the same purpose. Is there any situation where they behave differently? In other words, is there a situation where 

hasValue() != !nil()
?

If a field contains a bad reference (i.e. sys_id of a non-existent record), does 

hasValue()
return true or false?

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3 REPLIES 3

MB26
ServiceNow Employee

‎01-17-2011 10:24 AM

From my testing it would appear that hasValue() and nil(), being boolean results, are just opposites to each other. hasValue() returning true and nil() returning false for a particular situation. I did test the bad reference field situation you mentioned. e.g. I created a CI, associated it to an incident, then deleted the ci. When I query the task_ci table with this, I get the below result.



var gr = new GlideRecord('task_ci');
gr.addQuery('task','383982cf0a0a3c18007c3654c72a565d');  // sys_id of the incident record
gr.query();
while (gr.next()) {

if(gr.ci_item.nil()) {
  gs.print("NIL: " + gr.ci_item);
  gs.print("NIL: " + gr.ci_item.getDisplayValue());
  }
else{
  gs.print("NOT NIL: " + gr.ci_item);
  gs.print("NOT NIL: " + gr.ci_item.getDisplayValue());
}

if(gr.ci_item.hasValue()) {
  gs.print("Has Value: " + gr.ci_item);
  gs.print("Has Value: " + gr.ci_item.getDisplayValue());
  }
else{
  gs.print("Has NO Value: " + gr.ci_item);
  gs.print("Has NO Value: " + gr.ci_item.getDisplayValue());
}
}

Result:
*** Script: NOT NIL: 951dc14d0a0a3c180103775aab6a2d57
*** Script: NOT NIL:
*** Script: Has Value: 951dc14d0a0a3c180103775aab6a2d57
*** Script: Has Value:

Which also tells me they are merely the opposite boolean results of each other.


john_roberts
Mega Guru

‎01-17-2011 10:39 AM

hasValue is a simple method that returns !nil(). Since an orphaned record still leaves a sys_id in the reference field is will appear that is has a value since it does in the database.

If you want to check for a valid reference you can use:
gr.refField.hasValidReference()


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Jim Coyne
Kilo Patron
In response to john_roberts

‎09-10-2011 01:48 PM

I'm trying to use hasValidReference() in a workflow "If" activity but it is returning "false" all the time, even when there are valid entries in the Manager field.



answer = ifScript();

function ifScript() {
  if (current.request.requested_for.cost_center.manager.hasValidReference() || current.request.requested_for.cost_center.parent.manager.hasValidReference()) {
    return true;
  }
  return false;
}

I can't find any documentation for that function anywhere.


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