INTRODUCTION

DELPHI, COM AND THE OBJECT MODEL

WHY DOES DELPHI SUPPORT COM?

COM/DCOM AS AN ENTERPRISE TECHNOLOGY
IS COM THE ONLY DISTRIBUTED OBJECT SOLUTION?
CORBA
Server-Side Java/RMI

WHY DO WE NEED COM?

INTERACTION WITH OTHER COM BASED PRODUCTS
EXPANDING OUR COMPONENT MARKET (VB, POWERBUILDER, IE)
INTEGRATION/JUNCTION BETWEEN COM/CORBA == OPPORTUNITY
STILL CONFUSED ABOUT COM? A WORD ABOUT MICROSOFT MARKETING...
COM - COMPONENT OBJECT MODEL
DCOM - DISTRIBUTED COMPONENT OBJECT MODEL
A HIERARCHICAL VIEW

COM IN A NUTSHELL

A DIFFERENT OBJECT TECHNOLOGY BASED ON BINARY COMPATIBILITY
COM: A SET OF OVERLAPPING TECHNOLOGIES
OLE AUTOMATION
OLE DOCUMENTS
ACTIVEX
DCOM

COM: A DEEPER LOOK

INTERFACES

Interfaces Under The Hood
Interfaces: Contracts Between Clients and Objects
Multiple Interfaces
Extending COM Objects via New Interfaces

STANDARD INTERFACES

IUnknown
IDispatch
VTABLES

DISPATCH INTERFACES
DUAL INTERFACES
GUIDS
CLASS FACTORY
MARSHALING
TYPE LIBRARIES
GUIDS & THE REGISTRY

COM-MON TOOLS OF THE TRADE

IDL
MIDL
OLEVIEW

DELPHI'S COM TOOLS

TYPE LIBRARY EDITOR
TLIBIMP UTILITY
DELPHI COM/ACTIVEX WIZARDS

Automation Object Wizard
ActiveX Control Wizard
ActiveX Library Wizard
ActiveForm Wizard
Property Page Wizard
Type Library Wizard

DELPHI'S COM LANGUAGE EXTENSIONS

INTERFACE KEYWORD
DISPINTERFACE KEYWORD
DISPID KEYWORD
DELPHI'S COM-RELATED CLASSES

TAutoObject
TActiveXControl
TOleContainer

DELPHI COM COMPATIBLE DATA TYPES

OLE AUTOMATION SERVERS

TYPES OF SERVERS
USING AN EXISTING SERVER: EXCEL FROM INSIDE DELPHI

Excel Exposed Methods and Properties
Using Variants
Using TLIBIMP.EXE To Create a Type Library

HANDS ON: A SIMPLE OLE AUTOMATION SERVER EXAMPLE

Visual vs. Non Visual Servers
Creating the server Project
Using the OLE Automation Wizard
The Generated OLE Server Code
The Generated Type Library Object Pascal Code
Creating the Client

A MORE COMPLEX EXAMPLE: AN APPLICATION LOGIN LICENSE COUNT SERVER MANAGER

The Specification
Writing the server
ClearMessage(username:Widestring)

USING ACTIVEX CONTROLS

CREATING ACTIVEX CONTROLS

PRE-REQUISITES: UNDERSTANDING DELPHI VCL CUSTOM COMPONENTS
CREATING A NEW ACTIVEX COMPONENT USING THE ACTIVEX WIZARD

Selecting from VCL Base Class
Include Design Time License
Include Version Information
Include About Box
Creating the component.

WALKING THROUGH THE GENERATED SOURCE

The Type Library Unit (DateTimePickerXControl.Pas)
The Implementation Unit (DateTimePickerImpl1.Pas)

EXPLORING WITH THE TYPE LIBRARY EDITOR

Exploring The Exposed Properties and Events
Surfacing A New Property

COMPILING TO OCX CONTROLS
REGISTERING THE CONTROL
TESTING THE COMPONENTS

Visual Basic

DISTRIBUTING THE ACTIVEX CONTROL

Web Deployment Options

PROPERTY PAGES

INTERNET EXPLORER/HTML ISSUES WITH DELPHI ACTIVEX CONTROLS

USING ACTIVEX CONTROLS IN INTERNET EXPLORER
SPECIAL CASE: USING OBJECT PARAM TAGS

ACTIVEFORMS

A SPECIALIZED TYPE OF ACTIVEX CONTROL: TACTIVEFORM
DATABASE BDE ISSUES
INTRANETS, NOT INTERNETS
A SIMPLE EXAMPLE: ANIMALS.DBF ON THE WEB

DCOM WITH OLE AUTOMATION

REMOTE COCLASS CREATION

coCreateRemoteComObject

FURTHER READING AND EXPLORATION

BOOKS
ARTICLES
ONLINE RESOURCES
BORLAND/INPRISE USERNET NEWSGROUPS