Getting Started with Webobjects
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Getting Started With WebObjects May 2001 Apple Computer, Inc. Enterprise Objects and Enterprise © 2001 Apple Computer, Inc. Objects Framework are trademarks of All rights reserved. NeXT Software, Inc., registered in the United States and other countries. 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Contents Preface Preface 7 About WebObjects 7 About This Book 7 Where to Go From Here 8 Chapter 1 Creating a Simple WebObjects Application 9 Creating a WebObjects Application Project 11 Examining Your Project 14 Launching WebObjects Builder 16 Creating the Page’s Content 19 Entering Static Text 19 Using the Inspector 20 Creating Form-Based Dynamic HTML Elements 21 Resizing the Form Elements 23 Binding Elements 24 Creating Variables 24 Binding the Input Elements 27 Implementing an Action Method 29 Creating the Application’s Output 30 Building and Running Your Application 33 Chapter 2 Enhancing Your Application 37 Duplicating Your Project 37 Creating a Custom Guest Class 38 Binding the Class’s Instance Variables to the Form Elements 40 Creating a Table to Display the Output 41 Adding Dynamic Elements to Table Cells 43 Binding the Dynamic Elements in the Table 44 Creating the Guest Object 44 3 Apple Computer, Inc. May 2001 CONTENTS Keeping Track of Multiple Guests 47 Creating a Guest List 47 Adding Guests to the Guest List 49 Adding a Second Component 50 Using a Repetition 52 Adding the Finishing Touches 54 Clearing the Guest List 54 Adding a Dynamic Hyperlink 55 Chapter 3 Creating a WebObjects Database Application 59 The Movies Application 60 Enterprise Objects and the Movies Database 62 Enterprise Objects and Relationships 64 Defining the Model 65 Creating a New Model File 65 Choosing What to Include in Your Model 66 Choosing the Tables to Include 69 Specifying Primary Keys 70 Saving the Model 72 Designing the Main Page 74 Starting the WebObjects Application Wizard 74 Specifying a Model File 75 Choosing an Entity 76 Choosing a Layout 76 Choosing Attributes to Display 78 Choosing an Attribute to Display as a Hyperlink 79 Choosing Attributes to Query On 80 Running Movies 81 Examining Your Project 82 Examining the Variables 83 Examining the Bindings 85 Bindings in the Query Part 85 Bindings in the Repetition Part 86 Bindings in the Editing Part 87 Refining Main.wo 89 Specifying a Sort Order 91 4 Apple Computer, Inc. May 2001 CONTENTS Specifying Default Values for New Enterprise Objects 92 Setting a Date Format 93 Setting a Number Format 94 Optional Exercise 94 Adding the MovieDetails Page 98 Creating the MovieDetails Component 98 Storing the Selected Movie 98 Navigating from Main to MovieDetails 99 Designing MovieDetails’ User Interface 100 Adding Date and Number Formats 101 Navigating from MovieDetails to Main 102 Running Movies 102 Refining Your Model 103 Opening Your Model 103 Removing Foreign Keys as Class Properties 104 Adding Relationships to Your Model 105 Using the Advanced Relationship Inspector 108 Where Do Primary Keys Come From? 110 Setting Up a Master-Detail Configuration 111 Creating a Detail Display Group 111 Adding a Repetition 115 Configuring a Repetition 115 Running Movies 116 Updating Objects in the Detail Display Group 116 Managing a WODisplayGroup’s Selection 118 Adding a Form 118 Adding a Talent Display Group 119 Configuring the Browser 120 Adding Insert, Save, and Delete Buttons 122 Adding Behavior to Your Enterprise Objects 123 Specifying Custom Enterprise Object Classes 124 Generating Custom Enterprise Object Classes 124 Adding Custom Behavior to Talent 125 Providing Default Values in MovieRole 125 Running Movies 126 5 Apple Computer, Inc. May 2001 CONTENTS Glossary 127 6 Apple Computer, Inc. May 2001 PREFACE Preface About WebObjects WebObjects is an object-oriented environment for developing and deploying World Wide Web applications. A WebObjects application runs on a server machine and receives requests from a user’s web browser on a client machine. It dynamically generates HTML pages in response to the user’s requests. WebObjects provides a suite of tools for rapid application development, as well as prebuilt application components and a web application server. WebObjects is flexible enough to suit the needs of any web programmer. You can write simple WebObjects applications in a matter of minutes. For more complex projects, WebObjects makes it easy by performing common web application tasks automatically and by allowing you to reuse objects you’ve written for other applications. About This Book This book contains three tutorials that help you learn what WebObjects is and how to use it: About WebObjects 7 Apple Computer, Inc. May 2001 PREFACE Preface I “Creating a Simple WebObjects Application” (page 9), teaches you the basic concepts and steps involved in creating a WebObjects project, using the Project Builder and WebObjects Builder tools. You’ll create a simple application that takes input from a user and displays it. I “Enhancing Your Application” (page 37), extends the capabilities of your application and shows you additional techniques you use when working with WebObjects. I “Creating a WebObjects Database Application” (page 59), teaches you how to create a more complex application, one that accesses a database. WebObjects can run on several platforms. Screen shots in this book are for Windows 2000 systems; if you are running on a different platform, the look of your windows may vary slightly. Where to Go From Here After you have worked through the tutorials in this book, you should have a good working knowledge of WebObjects. For more in-depth information about how WebObjects works, read the WebObjects Developer’s Guide. Other valuable information about WebObjects is available on the WebObjects CD. You can access all online information through the WebObjects home page. 8 Where to Go From Here Apple Computer, Inc. May 2001 CHAPTER 1 1 Creating a Simple WebObjects Application This chapter introduces you to the basic concepts and procedures of developing WebObjects applications. You’ll develop, in stages, a simple application for the World Wide Web. The application you’ll write is called GuestBook. When you’ve finished the steps in this chapter, your application will have a single web page containing a form that allows users to enter their names, e-mail addresses, and comments. When the form is submitted, the application redraws the page with the user’s information at the bottom. 9 Apple Computer, Inc. May 2001 CHAPTER 1 Creating a Simple WebObjects Application In “Enhancing Your Application” (page 37), you will add features to the application, including a second page, a table that displays information from multiple users, and hyperlinks. 10 Apple Computer, Inc. May 2001 CHAPTER 1 Creating a Simple WebObjects Application This application illustrates the basic techniques you use to create a WebObjects application. You’ll use two primary tools, Project Builder and WebObjects Builder. Project Builder is an integrated software-development application. It contains a project browser, a code editor, build and debugging support, and many other features needed to develop an application. In this tutorial, you’ll learn to use Project Builder to: I Create a new WebObjects application project.