Re: Conventions for writing a COM Object model
simon_oleary99@yahoo.co.uk wrote:
Craig says:
"7. _NewEnum on collections objects is a method, not a property"
Now, everywhere I look _NewEnum is defined as a property, not a
method. Does anyone understand the signifcance of Craig's statement?
_NewEnum as a property works just fine. I've never tried it as a method,
and never seen anybody make it a method. I wouldn't be surprised if
either works: it's common for scripts to pass (DISPATCH_PROPERTYGET |
DISPATCH_METHOD) flag combination to Invoke - especially VBScript where
accessing a property and calling a method with no parameters are
syntactically indistinguishable.
"5. When methods/properties take a numerical index, that index
must be 1 based (first item is 1, not 0)."
At our company, after careful consideration, we have decided to ignore
this advice, and go for 0-based (mainly based on the idea that hte new
.NET stuff does 0-based - any opinions from anyone else?
I've seen it both ways. There does not seem to be a hard-and-fast rule.
"44. No interfaces begin with the letter I unless the name of what
is being modeled begins with an I. For example, IncrementalSearch is
OK, but IWindows is not. The exception to this is if the interface is
to be implemented by the user. Example: IDTExtensibility2,
IDTCommandTarget, etc."
I've seen it both ways. In MSHTML, all interface names begin with I,
e.g. IHTMLElement. In Office, interface names don't tend to begin with
I, e.g. _Application, _Document, Paragraph (but IApplicationEvents,
which is indeed an interface client should implement).
It appears that the author of the article is mainly influenced by
conventions adopted for MS Office's object model (though I can't help
but notice that _NewEnum is declared as a property, not method, in all
Office collections). Other teams at MS adopt different conventions.
--
With best wishes,
Igor Tandetnik
With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925