VB Annoyances

mkaftor · August 6th, 2012, 10:55 PM

Annoyance1)

Code:

If objReferrence IsNotNothingAndAlsoNotString.IsNullOrEmpty(objReferrence.value) Then

Why not define a Shared property in a module?

Code:

PublicModuleModuleIs1
'verify reference points to an object, and it's value is valid
  PublicReadOnlyProperty IsProperObjectAndValue(objReferrence AsObject) AsBoolean
   Get
     Return objReferrence IsNotNothingAndAlsoNotString.IsNullOrEmpty(objReferrence.value)
   EndGet
 EndProperty
  o   o   o
EndModule

then use the following line instead:

Code:

If IsProperObjectAndValue(objReferrence) Then

Willl this not be more readable?
2) I have tried to do the same for IsPostBack, as follows:

Code:

PublicReadOnlyProperty IsFirstPageRequest AsBoolean
 Get
   ReturnNotPage.IsPostBack
 EndGet
EndProperty

NOTE: the expression in red causes an error.
Any suggestions to correcting the problem?
Thanks,
Michael Kaftor

Imar · August 7th, 2012, 03:51 AM

Re 1: yes, you could if you wanted to, although you probably want to type the objReference parameter as a string.

Re 2: "the expression in red causes an error" is a bit vague. What error do you get and when? Where did you try this code? In the Module? If so, it makes sense as the module doesn't have access to the Page instance.

I would probably implement this as an extension method on the Page class, or not implement this at all as IsPostBack is, once you get the hang of it, just the reverse of IsFirstPageRequest ;-)

If you post code, can you please paste it in Notepad first to remove color coding and then use the forum editor's Code toolbar button to wrap your code in code tags. Otherwise, this forum messes up the code.

Cheers,

Imar

mkaftor · August 11th, 2012, 06:46 PM

Thanks for all your help. This was exactly what the doctor ordered and I was not aware of this language feature. As you said, after a while one gets the hang of it, except at debug time -- that I need to pay extra attention to the statement;
Here is the code that does the trick:

Code:

Imports Microsoft.VisualBasic
Imports System.Runtime.CompilerServices
 
Public Module ModuleExtensions
   'Is initial page request (v. IsPostBack)
   <Extension()>
   Public Function IsInitialRequest(ByRef aPage As Page) As Boolean
      Return Not aPage.IsPostBack
   End Function
 
End Module