getNameIDs: Compute the numeric identifiers for DCOM (method) names.

In omegahat/SWinTypeLibs: Type Library Information Reader

Compute the numeric identifiers for DCOM (method) names.

Description

This function uses the type library to compute the mapping of names, such as method names, to the numeric identifiers used in dispatching a a call using those names.

The .COM functionality used to invoke a method first sends a query to resolve the identifiers for the names in the method call. Then it uses these to actually make the call. Therefore, precomputing these identifiers and using them in calls can improve the efficiency of the call by avoiding the first step.

This information is also used when we implement a DCOM server in R. When other clients query the identifier for a name of a method in our server's interface, we must respond appropriately. When implementing already defined, established interfaces, again precomputing the name-identifier map helps.

This is a generic function that operates on various different pairs of input types.

Usage

getNameIDs(obj, context)

Arguments

obj	the object which is to be interrogated for the name-identifier mapping.
context	support information in which some methods will resolve the name-identifier connections. For example,

Author(s)

Duncan Temple Lang <[e-mail]>

References

http://msdn.microsoft.com/library http://www.omegahat.org/RWinTypeLibs

See Also

.COM and the ids argument. COMInterfaceServerInfo-class and its ids slot.

Examples

## Not run: 

     # FunctionInvokeDescription and an ITypeInfo.
   funcs = getFuncs(lib[["_Application"]])
   getNameIDs(funcs$Quit, lib[["_Application"]])

    # include parameters, although these will come back as 0, 1, ...
   getNameIDs(funcs$GetSaveAsFilename, lib[["_Application"]])

    # Instead of getting the FunctionInvokeDescription object first,
    # let getNameIDs do the work.  Works for arbitrary objects
    # in the ITypeInfo, not just FunctionInvokeDescription objects,
    # but property set and get methods, etc.
   getNameIDs("Quit", lib[["_Application"]])

    # Get the name mappings for all the elements of an ITypeInfo,
    # e.g. all functions all at once.
   getNameIDs(lib[["_Application"]])   

## End(Not run)

omegahat/SWinTypeLibs documentation built on Jan. 17, 2024, 6:40 p.m.