getValue on Integer, true false, and other non String in Scopped applications

[corbettbrasing1]

I am on a quest for consistency in my code.   First off I work exclusively in scoped apps so I cannot use things like JSUtils as they are not available in a scoped application.   You also cannot use .nil() in scopped applications either.

Here is my goal:   I want to find a consistent way of getting values while avoiding pointer conflicts especially in loops but keep the proper variable type.

I am all about setters and getters but my problem is that GlideRecord.getValue() ALWAYS returns a string.   So if I want to get the value of true/false field and then use that value in an expression for example I cannot

I want to be able to use the "falsey" and "truthy" principles of javascript.   See this if you don't know what I am talking about Truthy and Falsy Values in JavaScript - A Drip of JavaScript

EMPTY Field examples

if(GlideRecord.getValue("fieldName")){//this will ALWAYS be true since get Value returns a string, even if its empty it returns a string of "null"
           //do something
}

But in order for that to actually work I need to do

if(GlideRecord.fieldName){//this does work as it returns an Integer of 0 which is false . 
         //do something
}

TRUE FALSE Fields

var bool1 = GlideRecordObject.trueFalseField; //this will return a BOOLEAN value
var bool2 = GlideRecordObject.getValue("trueFalseField");//this will return a STRING, which means I cannot do Boolean("0") as this will evaluate to true. 
var bool3 = GlideRecordObject.getDisplayValue("trueFalseField"); // returns a STRING of "true" or "false" which means I also cannot use Boolean("false")
//as any String is considered truthy and will return true

Dot walking though has the potential for pointer conflicts especially in loops I know for reference fields but I am not sure if they do for non reference fields.

So....what is the answer?   As far as I can tell I only have 3 options

1.   Use exact comparison with == against another string and always use getValue() which means I cannot use "truthy" and "falsey" in my logic

2.   Dot walk so I can use "truthy" and "falsey" and risk pointer conflicts.

3.   Create my own library that extends GlideRecord so I have all the functions and then make my own version of get value that return the proper type as far as "falsey" and "truthy" go.

Thoughts?   I don't like the idea of a mixed bag of dot walking and getters and setters.

[srinivasthelu]

Hi corbett,

Scoped GlideSystem has gs.nil function

http://wiki.servicenow.com/index.php?title=Scoped_GlideSystem_API_Reference#gsc.tab=0

[corbettbrasing1]

That does not give full "falsey" or truthy evaluation

[corbettbrasing1]

it means can only use it to test an empty field.   So that is helpful but still does not fully answer my question.  

[Krauzi]

TL;DR:

if (<GlideRecord>.<TrueFalseField>) {
  // this works as you'd expect, even though you are technically using if on a GlideElement
}

var boolValue = !!<GlideRecord>.<TrueFalseField>; // cast to boolean

Long Version:

Even though this is a pretty old thread, I decided to answer it because its one of top google results for "ServiceNow GlideRecord Boolean". Because of this I wanted to give a few remarks the the statements made from OP:

"GlideRecord.getValue() ALWAYS returns a string."
This is not entirely correct. If no value is set for a certain field in a row that is represented by a GlideRecord, getValue("field") will return null (by the way: typeof null === "object").

var bool1 = GlideRecordObject.trueFalseField; //this will return a BOOLEAN value

var bool2 = GlideRecordObject.getValue("trueFalseField");//this will return a STRING, which means I cannot do Boolean("0") as this will evaluate to true. 

var bool3 = GlideRecordObject.getDisplayValue("trueFalseField"); // returns a STRING of "true" or "false" which means I also cannot use Boolean("false")

//as any String is considered truthy and will return true

bool1 is NOT a Boolean! It is a GlideElement (typeof bool1 === "object" && bool1 instanceof GlideElement). 
The last comment is also incorrect. A empty String evaluates to false.

My advice for working with True/False-Fields in scripts is probably best described by the following code example:

function isActive(taskSysId) {
  var gr = new GlideRecord("task");
  if (gr.get(taskSysId)) {
    return !!gr.active; // !! is idempotent
  }

  return false;
}

function getMessageIfActive(taskSysId, msg) {
  var gr = new GlideRecord("task");
  if (gr.get(taskSysId) && gr.active) {
    return msg;
  }

  return "";
}

function getTaskWithActiveValue(active) {
  var gr = new GlideRecord("task");
  gr.addQuery("active", active);
  gr.setLimit(1);
  gr.query();
  gr.next();
  return gr.getValue("sys_id") || "";
}

var inactiveTaskSysId = getTaskWithActiveValue(false);
gs.info("using task with active=false");
gs.info("if (gr.active): " + getMessageIfActive(inactiveTaskSysId, "hello world from inactive task"));
gs.info("!!gr.active: " + isActive(inactiveTaskSysId));

gs.info("");

var activeTaskSysId = getTaskWithActiveValue(true);
gs.info("using task with active=true");
gs.info("if (gr.active): " + getMessageIfActive(activeTaskSysId, "hello world from active task"));
gs.info("!!gr.active: " + isActive(activeTaskSysId));

The output for the code example is:

using task with active=false
if (gr.active): 
!!gr.active: false

using task with active=true
if (gr.active): hello world from active task
!!gr.active: true