I want to call an ActiveX DLL or OLE2 object from ABAP.
I already know the syntax of how to instantiate the object & execute the methods:
data: my_object type ole2_object.
create object my_object <ole2object>.
call method of my_object <objectmethod>.
But given a particular application, how do I know if this is supported, what the values/names of ole2object and objectmethod is?
Transaction SOLE supplies a table of OLE Applications, among this is Excel.Application which I know can be instantiated as an OLE object, so it looks like you have to add the OLE2 app to this table first, but once again where can I read the data like CLSID & LibType from - is it published as part of the application?
Objects are coming from the table TOLE. Their methods and propeties are stored into table OLELOAD.
I found some time ago somes documents (this one and this one) that contained indications of how you can find the properties and methods.
Indication on the CLSID are succint, but it seems to be the value in the register with HKEY_CLASS_ROOt/CLSID that goes with the application indicated (ie VISIO.APPLICATION for exemple). If you search this application value with regedit, you'll find the corresponding CLSID.
Hope it's helping
Guillaume
In this case, you're simply using OLE2 to access a COM interface. If you're into accessing Office applications, you might want to take a look at KB222101. For other applications and libraries, you'll need the API documentation, some suitable examples (not necessarily in ABAP, VB will do just fine). a pointed stick to poke the developer with or all three of them...
Oh, and there's a tool called OLE/COM Object Explorer by MiTeC that can be downloaded for free from their website. Haven't used it myself, but it looks like it might be helpful.
Related
I have referenced the SketchUp.exe into a project or at times an extracted TLB from the SketchUp.exe and can see the object model but cannot create an instance of any object in it.
I found out it may be a non-shared object or set to PublicNoncreatable and thus unlike AutoCAD or Excel I cannot create object instances.
When working with Adobe Acrobat I found it had the same problem but had a non-viewable object name which allowed instancing its objects.
Maybe SketchUp also has a completely hidden object or method that allows this. In the mean time is there a way to apply and instance of the object by overriding its non-share status as shared?
SketchUp's COM API is no longer supported. You may want to take a look at the new C API.
I wanted to create a few macros for LibreOffice using BASIC. However I cannot find the API description. It is absent in help as well as in interet. When I try to google it I get masses of examples in C++, Java, Python, but not a single www with BASIC.
For example where from can I get the hierarchy of objects and their methods?
LibreOffice Basic uses essentially the same API as PyUNO and Java. That is, they all use the UNO API. To get started, the OpenOffice development guide helpfully describes the two main ways to step into the object hierarchy, the Global variables ThisComponent and, less commonly, StarDesktop. There also is a specialty variant in LO Base, ThisDatabaseDocument. To get the properties and methods of these objects, execute MsgBox oObject.DBG_properties or .DBG_methods. It often is easier to copy the longer lists that are returned by this method into a text editor for searching. You will find that all, or nearly all, of the methods and properties you reveal will be described in the LibreOffice UNO IDL API. The documentation for the API is not that descriptive, but you will be able to fill in some essential details using that resource Every Object has properties that can be reviewed by .DBG_properties.
The key properties for navigating the object hierarchy are .Parent, .Model, .CurrentController and occasionally .Source. The key methods are getByName() and getByIndex(). It also is helpful that events which trigger macros typically return an event object whose source or parent is the object that initiated the macro, for example, a command button. This object can be accessed by referring to it along with the Sub, i.e., Sub SubName (oEventObject As Variant)....
Either I don't understand COM objects, either it's all that confusing.
I frequently 'create' , 'dispatch' COM objects - either in Python, either in VB ( Obj = win32com.client.Dispatch('Visum.Visum') or Obj = CreateObject("Excel.Application") respectively).
That's easy, obvious and everything's fine.
But how can I:
a) connect to COM object which is already running
b) get list of running processes which are COM objects
in VB what is the reference, and additional info on: CreateObject command. In Python it's part of well defined, comprehensive library of win32com whereas in VB it's just single method without reference: http://msdn.microsoft.com/en-us/library/7t9k08y5(v=vs.80).aspx
Highly confusing (COM object,server? connection, dispatching, registering??)
Thanks for claryfying
Rafal
i2
First of all, I would suggest reading a good introduction to COM. Personally, i think that 'Essential COM' by Don Box is the best book about COM. Spending a few hours with it will save you many hours later.
That being said, let's move to your questions.
a) In order to retrieve an existing COM object from VB, you need to call GetObject function. This will only work for COM objects which are registered with Running Object Table. Excel does this, so there shouldn't be any problems with that.
b) as Hans Passant correctly noted, this question doesn't make sense. Processes and COM objects are completely unrelated things, except for the fact that processes host the COM objects. It is similar to asking 'which processes are instances of class X'. However, a process can host a COM object (or many of them). These object can be alive only temporarily, so what would you expect there? Besides, many COM classes are implemented within dlls, but created instances obviously are hosted within a process - so what would you expect there?
COM technology is something I didn't not use for a while, so sorry if some info might be wrong (anyway, I've got my book "Inside COM+ base services" with me!)
Briefly speaking, let's give a simplified definition of a COM object: it nothing else than a standard DLL with classes exposing a standard interface IUnkown with the following methods:
AddRef: to register a client consuming the COM object
Release: to unregister a client (usually unused objects stop running, but other might remain resident)
QueryInterface: to get the address of a function
QueryInterface is used to dynamically retrieve the address of a function (late-binding) which is powerful (you don't have to know the DLL at compile time) but time consuming. On the other hand, you can directly reference the addresses of the functions at compile-time because those DLL are registered in the system (all the informations are stored in the registry)
Creating a new object or getting the address of a running object is done through RPC (remote procedure call) which will load and/or play the role of a proxy
So to create a new instance of a COM object, you will call CreateObject (in VB) (Co)CreateInstance in VC++ (or even c#?), while to get an executing instance, you might want to call GetObject().
Getting the list of COM objects is not that easy (I guess not possible at all) because, as told earlier, a COM object is nothing else but a DLL: this means that the library will mainly load in the address space of each process which access is private. Even for out-process COM objects (opposite to in-process) which are object shared between many processes (i.e.: Excel is an out-of-process COM object: you don't load the DLL in your application's address space), they are loaded by a host (rpc.exe or a proprietary host)
Hope this helps
Serge
I was convinced that there is no way to find COM dependencies of an ActiveX but to my surprise OLEVIEW shows some comments Like:
// TLib : // TLib : OLE Automation : {00020430-0000-0000-C000-000000000046}
importlib("stdole2.tlb");
// TLib : Visual Basic runtime objects and procedures : {EA544A21-C82D-11D1-A3E4-00A0C90AEA82}
importlib("3");
I tried to extract the same information using TypeLibInfoFromFile but based on what I find in MSDN, there is no Api that provides this information. Are you aware of a method to extract this information from OCX or it's Tlb file? Knowing that all my ocxes are compiled with vb6 can I trust this informaion for Imported(Explicitly not in code) interfaces?
Well, I've found the answer to this question. I'll write it here just in case someone would search for the same question. It's possible to find some of dependencies but you can never be sure if you have found them all. Basically you must enumerate every type and interface, and every member of each type to find all types in the module and for every type you find you should check to see if it's in an external TypeLib. in the end you have a List of Typelibs referenced.
The problem with this method lays in the fact you find only the types that are used in the public interface (fields, return values and parameters) and you miss every local object or dynamically created ones. That said you can check this link for an implementation or better yet this one.
I am looking for "typical" way one navigates MSDN to get a COM class to do what they want.
Example problem: I am looking for an API way to unblock a local file (remove internet zone/mark of the web from a file programmatically).
I found one post on stackoverflow.com that talked about clsid_persistentzoneidentifier. so i searched in MSDN and got to http://msdn.microsoft.com/en-us/library/ms537029(VS.85).aspx. What I am looking for,is what one does after they get to this url. From this location, I am not able to figure what the sequence of operations should be. How do I connect this IZoneIdentifier to IPersistFile? etc. There must be something basic that I am missing wrt COM related documentation. MSDN has interfaces and objects, but nothing that helps me visualize a "sequence" diagram of sorts. Nothing that will get me to understand which COM objects are from same class. hence can/or should be QueryInterfaced, adn which should be CoCreated.
The documentation for that indicates a few things.
The first is that you can call CoCreateInstance, passing CLSID_PersistentZoneIdentifier to get an implementation of these two interfaces:
IPersistFile
IZoneIdentifier
It also says:
Use IPersistFile to attach the object
to the target file and IZoneIdentifier
to examine or to manipulate the zone
ID.
That being said, you can look at the documentation for IPersistFile here:
http://msdn.microsoft.com/en-us/library/ms687223(VS.85).aspx
It shows that there is a Load method, which is what you want to call with the filename to load the implementation with details about the file.
From there, you can call QueryInterface on the IUnknown interface implementation to get the IZoneIdentifier interface and then call the Remove method on it to set the zone to the local machine.
For that purpose, if it's not obvious from the documentation, I like to find sample programs in which relevent APIs are used: either using Google, or perhaps from whichever of the Microsoft SDKs is relevent.
Microsoft SDKs, for example this one, include sample programs.