Custom Decisions

[mcfadyenj]

i have setup a couple of custom decisions.

it seems if you return anything that is enough to trigger a "true" evaluation of the decision.

is there something that should be done on a negative result other than not returning anything?

i.e. should an exception be thrown?

if (currentSysprep == "true")
{
return currentSysprep; 
}

else

{

  // should something be done here?

}

[Burke- · Accepted solution]

Yes, you should:

return false;

All decision boxes should return a true and a false ...

[tschoergez]

Hi!

For the reference: This is expected behaviour in Javascript. Everything which is not explicitly

• 0
  
• -0
  
• null
  
• ""
  
• false
  
• undefined
  
• NaN
  

means true.

See here:

http://www.w3schools.com/JS/js_obj_boolean.asp

Cheers,

Joerg

[tschoergez]

BTW: Custom Decisions can also throw exceptions, but this should only be used if there is really an unexpected error inside the script.

You cannot "handle/catch" the execption outside, because there is no Exception Binding for Custom Decisions available, so your complete workflow will fail if you throw an Exception insinde a decision.

It's an absolute "Anti-pattern" to use exceptions to implement some business-logic, so you should follow Burke's tip and always return a clear "true" or "false". (makes it also easier to maintain, if you read the code in several month again 🙂 )

Regards,

Joerg