Top

Creating a WebObjects Database Application

One of the most powerful features of WebObjects is its ability to provide access to databases. To do so, it uses a framework called the Enterprise Objects Framework. This chapter introduces you to the Enterprise Objects Framework by showing you how to create a simple database application. The steps you take in creating this application demonstrate the principles you'll use in every other application you develop with the WebObjects and Enterprise Objects Framework.

The application you'll create in this tutorial is called Movies. It makes use of a sample database, the Movies database, that contains information about movies. Before you do this tutorial, you need to set up the Movies database as described in the Post-Installation Instructions. In addition, if you aren't familiar with Project Builder and WebObjects Builder, read the first tutorials in this book, "Creating a Simple WebObjects Application" and "Enhancing Your Application", which introduce basic concepts and procedures you should know before you go on.

In this tutorial, you will:

• Use the WebObjects Application Wizard to create a fully functional Main component that reads and writes from the Movies database.

• Create and configure display groups for interacting with a database in terms of objects.

• Create bindings between display groups and a user interface.

• Write code to manipulate display groups' selected objects.

• Set up display groups in a master-detail configuration.

• Use EOModeler to maintain a model file.

• Create custom enterprise object classes.

The Movies Application

Enterprise Objects and the Movies Database

Enterprise Objects and Relationships

Designing the Main Page

Starting the WebObjects Application Wizard

Specifying a Model File

Choosing an Adaptor

Choosing What to Include in Your Model

Choosing the Tables to Include

Specifying Primary Keys

Specifying Referential Integrity Rules

Choosing an Entity

Choosing a Layout

Choosing Attributes to Display

Choosing an Attribute to Display as a Hyperlink

Choosing Attributes to Query On

Running Movies

Examining Your Project

Examining the Variables

Examining the Bindings

Bindings in the Query Part

Bindings in the Repetition Part

Bindings in the Editing Part

Refining Main.wo

Specifying a Sort Order

Specifying Default Values for New Enterprise Objects

Setting a Date Format

Setting a Number Format

Optional Exercise

Adding the MovieDetails Page

Creating the MovieDetails Component

Storing the Selected Movie

Navigating from Main to MovieDetails

Designing MovieDetails' User Interface

Adding Date and Number Formats

Navigating from MovieDetails to Main

Running Movies

Refining Your Model

Opening Your Model

Removing Primary and Foreign Keys as Class Properties

Adding Relationships to Your Model

Using the Advanced Relationship Inspector

Where Do Primary Keys Come From?

Setting Up a Master-Detail Configuration

Creating a Detail Display Group

Adding a Repetition

Configuring a Repetition

Running Movies

Updating Objects in the Detail Display Group

Managing a DisplayGroup's Selection

Adding a Form

Adding a Talent Display Group

Configuring the Browser

Adding Insert, Save, and Delete Buttons

Adding Behavior to Your Enterprise Objects

Specifying Custom Enterprise Object Classes

Generating Custom Enterprise Object Classes

Adding Custom Behavior to Talent

Providing Default Values in MovieRole

Running Movies

First Section