Apple WebObjects 3.5 - Manual (Page 114)

Chapter 3 Creating a WebObjects Database Application
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2. Using the Display Group Options panel, assign talentDisplayGroup ’s entity to
Talent.
Remember that to open the Display Group Options panel, simply
double-click the talentDisplayGroup variable in the object browser. The icon
initially displayed next to the variable indicates that initialization
parameters have not yet been set.
3. Configure talentDisplayGroup to sort its objects alphabetically (ascending)
by lastName .
4. Configure it to fetch on load.
After you configure talentDisplayGroup , the object browser shows a icon
next to the variable.
The Movies application uses a display group to provide Talent objects, but you
could fetch the Talent objects from the database without one. Display groups
provide a simple way to fetch, insert, update, and delete enterprise objects
without writing much, if any, code. To get finer-grained control over these
operations, you can work directly with an EditingContext object. An editing
context can do everything a display group does and much more, but you have to
write more code to use one. For more information, see the EditingContext class
specification in the Enterprise Objects Framework Reference.
Configuring the Browser
In a way similar to the way you create bindings for a repetition, create your
browser’s bindings.
1. Bind talentDisplayGroup.displayedObjects to the browser’s list attribute.
2. Bind talent to the browser’s item attribute.
3. Bind talent.lastName to the browser’s value attribute.
The value attribute tells the browser what string to display. For each item in
its list , the browser evaluates the item ’s value .
The browser in the MovieDetails page should display the actors’ full
names, but there isn’t an attribute for full name. In the next section, you’ll
create a custom Talent class that implements a
fullName method, but for now
just use talent.lastName as the value attribute.
A browser also has a selections attribute that should be bound to a vector of
objects. A browser’s selection can be zero, one, or many objects; but in the