What does "typeof window == 'undefined' " mean?

[ritaaudi]

Hi: We have the following script in our 'Resolve Now' UI action that is called every time the user clicks the 'Resolve Now' button:

if (typeof window == 'undefined') {

  serverResolve();

}

I am wondering if something is wrong with the code. What is window == 'undefined'? Is it always 'undefined'? When is it 'defined'?

Thanks for your help!

Rita

[Pradeep Sharma · Accepted solution]

Hi Rita,  

if(typeof window == 'undefined') means

1.Code that runs without 'onclick'.

2.Ensure call to server-side function with no browser errors

[ritaaudi]

Hi Pradeep: Yes that makes sense. So the code in the if always executes unless there are browser errors. Thx! Rita

[Sjoshi2]

Hi Pradeep,

For my instance UI action 'Resolve Incident' also has onclick value - resolveIncident(); and this function has body in the script section. And your comment says "1.Code that runs without 'onclick'." how exactly it works? I am stuck for that point.

[Pradeep Sharma]

Hi Shreya,

Please go through below link for more info on how it works.

Client & Server Code in One UI Action - ServiceNow Guru

Let me know if you have any questions.

[Sjoshi2]

Thank you so much.. Now I am much clearer with this idea.. Thanks.