OLE / COM Helia / Martti Laiho Sources: MSDN Kraig Brockschmidt: Inside OLE Orfali-Harkey-Erwards: Client/Server Survival Guide

OLE History OLE –Compound documents –Object Linking and Embedding (OLE) OLE –Component Object Model (COM) –OLE Automation OLE Controls, OCX 1994 ActiveX 1996 DCOM 1996 COM Distributed interNet Application Architecture (DNA) 1997

Object type ClassName ========= properties events … methods … Interfaces Property Get - read property Property Let - write property Property Set - assigns child objref to property Initialize Declared using Interface Definition Language (IDL)

DCOM Server Class - properties - events - methods (functions) Class - properties - events - methods (functions) ClassFactory IClassFactory(2) - CreateInstance - LockServer - GetLicInfo - RequestLicKey - CreateInstanceLic IUnknown - QueryInterface - AddRef - Release Interface - Get/Let/Set methods - set of methods.EXE or.DLL

Creating an Object IClassFactory(2) - CreateInstance - LockServer - GetLicInfo - RequestLicKey - CreateInstanceLic DCOM Server Class - properties - events - methods (functions) Class - properties - events - methods (functions) ClassFactory IUnknown - QueryInterface - AddRef - Release Client Instance - properties - vtable of methods Instance - properties - vtable of methods

Collection and Member indexing collection =========== methods: Add Count Item Remove Object instance Object instance... Collection.item(1) Collection.item(2) Collection.item(count) Collection(0) or

Collection Methods colObj colObj.Add colObj.Clear colObj.Remove colObj.Count colObj.item(..)

Type Library & Instance Object Type (class factory) Object instance Object instance caller Object caller Object Dim objRef As New or Set objRef = CreateObject(" " ) objRef COM Object Reference is an interface pointer to an object

OLE Technologies OLE Controls In-Place Activation (Visual editing) In-Place Activation (Visual editing) Linking Property Pages Property Pages Events Property Change Notification Property Change Notification Embedding Drag and Drop Uniform Data Transfer Uniform Data Transfer Persistent Objects Structured Storage Connectable Objects Connectable Objects Type Information Component Object Model: Objects and Interfaces OLE Automation Naming and Binding Naming and Binding OLE Documents Kraig Brockschmidt: Inside OLE, 1995

Object Linking and Embedding Document1Document2 Linked object Document1Document2 emb. obj Source object emb. obj Embedding a copy Linking the object

Automation Object Hierarchy Application Documents collection Document Object Rich properties collection Objects collection Rich property Enumerator - Open - Save - Close Kraig Brockschmidt: Inside OLE, 1995 (container) i.e. Font Hierarchy of...

Object Path Child Type properties methods Child Object Child Object Parent Type Parent Object Parent Object Parent.Child.Method [arguments]

DCOM Client Object proxy Object proxy Server Stub Actual object Actual object RPC

COM+ Load balancing In-memory databases Object pooling Queued components Event model Administration extensions Evolution of Component Services Microsoft Transaction Server Transaction services Resource pooling Just-in-time activation Role-based security Administration Distributed COM Remoting architecture Distributed component services COM Interface-based programming Basic component facilities Inside COM+