Oracle JHeadstart Developer's Guide - Downloads - Oracle

• Regenerate. You should get this (nodes in the picture expanded by hand to
show contents):
Each record is shown only once in the correct place in the tree structure.
5.6.5. Variation: Tree showing only Children of selected Parent
You might not want to show a tree of all rows in the database, but only of the child nodes
of a certain parent row. For example, you want the user first to select a department, and
then for that department show a tree of the employees of that department.
With JHeadstart you can generate that by having a hierarchy of groups, and only setting
the layout style to tree(-form) for a subset of child groups.
The steps described here assume that you have already built the tree as described in
section 5.6.3 Variation: Recursive Tree. We cannot use 5.6.4 Variation: Recursive Tree
with Limited Set of Root Nodes because it would not show any nodes unless the
department included a top manager in its employees. You already have a tree of
Employees, and now we will add a Department group in front of it.
• First ensure that the Application Module's data model includes the parentchild
relations we want to use. We should have a top level DepartmentsView
usage, with an EmployeesView child.
• In the Application Definition Editor, create a new Base Group and call it
Departments. Set the Data Collection to the top level DepartmentsView
usage. Enter a Tab Name, Display Titles, and a Descriptor Item.
• Set Advanced Search to samePage and Quick Search to singleSearchField, on
item DepartmentName.
• Make the Employees group of the recursive tree a detail group of the newly
created Departments group. Save, leave and reopen the Application Definition
Editor to reset the dropdown lists.
• Change the Tree Data Collection of the Employees child group to the child
usage of the Departments group.
• Change the Data Collection of the Employees child group from
'EmployeesViewTreeSelect' to the same child usage of Departments.
JHeadstart Developer’s Guide Generating Page Layouts 5 - 35