Lately a user on OTN JDeveloper and ADF forum ask how to cascade to tables instead of two LOV components. My first thought was to use an af:treeTable, however, this would give the user a different experience then you get from a cascading LOV. In the end I build a small test case using the HR db schema using the departments as master table and the employees of the selected departments as detail table. At the end of the post you’ll find the link to the sample workspace.
The sample is very simple as it only has the departments with the cascading employees view as data model.
Data model
The view controller is simple too. Its consists of only one page which holds a region. Inside the region are two panelCollection components, one holding the departments as table (read only, single selection mode) and one holding the cascading employees table (read only, single selection mode).
Region holding the cascading tables
The magic which make the sample work, is the partial trigger which is used on the employee table and is listening on the departments table. The selection of the employees is done in the model via the viewLink which is automatically setup when you create the business components from the HR tables.
PartialTrigger
When you run the sample, which was build using JDev 11.1.2.1.0, you see the that the first row of the departments table is selected and the employees of this department in the lower table.
Start of sample
If you select an other row in the department table you see the different employees in the lower table
Selection of an other department
To summarize this blog, I can say that the implementation of the use case did not need one line of java code. The solution was easy to archive by only using a declarative approach.
You can download the sample workspace, build with JDev 11.1.2.1.0 and depending on hte HR db schema, from here: BlogCascadingTables.zip
Please rename the file to ‘.zip’ after downloading it!
Timo Hahn
