How to override VBScript GetObject method in .NET - tridion

Question

I am having below code in VBScript
' Retrieve the keyword category for page section names
Set SectionCat = TDSE.GetObject(WebdavToUri(getPublicationWebDav(WEBDAV_SECTION_CAT)), 1)
' Retrieve the localized section keyword
Set SectionKeyword = SectionCat.GetKeywordByTitle(meta)
' Open the English translated section keyword
Set SectionKeyword = TDSE.GetObject(SectionKeyword.Id, 1, WEBDAV_UKEN_PUB)
SectionName = SectionKeyword.Title
Where WEBDAV_UKEN_PUB is the WebDavPath, now in VBScript GetObject method we have got option to pass three parameters 1) Item.ID, 2) TDSDefines.OpenModeEditWithFallback and 3) WebDavPath from where to make the object.
Now I want to write same logic in 2009 .Net templating, below is the sample code, I am trying to write but not able to get rid of VBScript Object.
Category cat = engine.GetSession().GetObject(WebdavToUri(getPublicationWebDav(Constants.WEBDAV_SECTION_CAT,package,engine), engine)) as Category;
if (cat != null)
{
//_log.Info("Category" + cat.Title);
Keyword keyword = cat.GetKeywordByTitle(meta);
//_log.Info("keyword 1" + keyword.Title);
keyword = engine.GetObject(Constants.WEBDAV_UKEN_PUB) as Keyword;
//_log.Info("keyword 2 " + keyword.Title);
if (keyword != null)
{
sectionName = keyword.Title;
}
keyword = null;
I am able to create Category object, however when I am trying to make Keyword object its getting failed and giving object reference error.
Do we have any class or method which work same like VBScript GetObject which will make the Object from the passed webdavpath or can somebody can give sample code on this.

Answer 1

I think your problem is here:
keyword = engine.GetObject(Constants.WEBDAV_UKEN_PUB) as Keyword;
You are using the WEBDav URL of a publication, and then attempting a dynamic cast to Keyword. You can't cast a Publication to a Keyword, so the cast fails and your keyword variable is assigned null.
Using dynamic casts in this way is an easy way to fool yourself. The "As" keyword (C# keyword not Tridion keyword) should be used when you don't know at compile time what type you expect. If you know that you expect an item of type Keyword, then you should write:
keyword = (Keyword)engine.GetObject(Constants.WEBDAV_UKEN_PUB);
This way - when the cast fails, you'll get an exception that identifies the problem correctly.

Answer 2

In TOM.NET we cannot get an object and specify which pub to read it from, we need to modify the TcmUri to be in context.
So:
Repository context = (Repository)session.GetObject(WEBDAV_UKEN_PUB);
TcmUri keywordInContext = new TcmUri(keyword.Id.ItemId, keyword.Id.ItemType, context.Id.ItemId);
Keyword keyword = (Keyword)session.GetObject(keywordInContext);