[R] setClass with a slot of RODBC

[David James]

Hi,

A couple of thoughts:

(1) The channel RODBC is an S3 object, thus there's no proper S4 class
associated with it.  From  ?setOldClass:
....
Description:

     Register an old-style (a.k.a. `S3') class as a formally defined
     class. The 'Classes' argument is the character vector used as the
     'class' attribute; in particular, if there is more than one
     string,  old-style class inheritance is mimicked.  Registering via
     'setOldClass' allows S3 classes to appear  in method signatures,
     and as a slot in an S4 class if a prototype is included.
...

(2) This question may be more appropriate for r-devel?

HTH,

--
David


On 6/1/07, adschai at optonline.net <adschai at optonline.net> wrote:
> Hi - I tried to get some answer before but there seems to have no one response. My question is that I have a class like below definition:
>
> setClass("DBManager",
>    representation(channel="RODBC"))
>
> My purpose of the conn slot is to hold a channel to database connection which is returned by a command like:
>
> channel <- odbcConnect("DB", uid="user", pwd="password")
>
> According to RODBC documentation, this channel is supposed to have a type of "RODBC". However, if I declare my class as above, R will complain that it does not know about "RODBC" type or class. Please clarify. Thank you.
>
> - adschai
>
>         [[alternative HTML version deleted]]
>
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