LOVs again! How to return multiple fields to calling form

Question

Hi
Newbie question, any help GREATLY appreciated :)
Is there a simple and easy way to return more than one field from a LOV.
I need this as I have a composite fk comprised of 2 fields, and as such need to return 2 fields from the LOV to the calling form.
(My environment: JDeveloper 9.0.5.2 build 1618)
CM

Answer 1

Thanks, you put me on the right track here. Further investigations show the following sample provided by OTN shows how to use both the session request/response values or a JavaBean to do this:
http://www.oracle.com/technology/sample_code/products/jdev/10g/ADF_UIX_UserInput.zip
As such I post my solution to my original post. Hopefully it's useful to someone beside myself. I have to write up my notes anyhow so it's no fuss to submit them to the forum. I must admit I'm a newbie and slightly demented Forms programmer so such solutions aren't so obvious to me. With this in mind please include the "standard disclaimer" here, with the addition "mileage may vary" warranty.
For these notes I've used the "HR" demo Oracle schema. In particular the tables departments and employees. As you know there is a master-detail relationship between these 2 tables, where each department may have one or more employees.
We have the requirement on a webpage to:
1) Provide an input-form-with-navigation to edit the employees.
2) Display the relating department_name field, rather than just showing the department_id which is meaningless to the user. For example if the employees.department_id = 40, we wish to show the department name "Human Resources" on the employees record.
3) Provide a LOV for the department ID field to allow the user to change the underlying department_id to a different master departments record.
4) Update 2) given a change via 3).
To do this do the following:
Entity Objects
1) Create default EO/VOs on both tables.
2) In the employees EO, create a new field "DepartmentName" to represent the derived department name field.
3) Set the new EO attribute's selected-in-query field.
4) In the query-column-expression field, enter a query to derive the department name field for each record in the detail-employees-EO.
eg. (SELECT dpt.department_name FROM departments dpt WHERE dpt.department_id = employees.department_id)
Ensure to include the brackets.
5) Apply the changes and accept the warning to create default data-type settings for the new attribute.
View Object
6) In the employees VO, include the new field DepartmentName as a selected attribute from the EO.
7) Apply the changes and accept the warning to create default data-type settings for the new attribute.
8) Test the model by running the ADF BC tester. Once running select the employees VO and step through the records, making sure the DepartmentName field has a value and changes appropriately according to the relating parent department_id.
UIX input-only-form
9) Create a new UIX web page employeesEdit.
10) From the data-control pallete, drag in the employees VO as an input-form-with-navigation.
11) For testing purposes it is also useful to have a create, delete, commit and rollback button, so includes these too.
12) Within the employees VO data-control, also drag across a messageLovInput for the DepartmentId. Position it under the existing DepartmentId messageTextInput within the UIX page. We'll remove the existing messageTextInput later, but it's useful to leave it in for testing purposes initially when the LOV returns values.
UIX LOV
13) Navigate to the default LOV page that has just been created for you.
14) Within the data-control pallete, expand the departments VO, select department ID then LOV-table from the drop-down, and drag this item onto the LOV page.
15) Save your changes.
16) Run your application. For an existing employee, invoke the department LOV and select an alternative department. Note on returning to the employees page the DepartmentID (both the messageTextInput and messageLovInput fields) are updated, but the DepartmentName is not. To do this we need to create a JavaBean to return multiple fields from the LOV to the original form.
JavaBean
17) Within your ViewController project, expand the ApplicationSources-View node.
18) Select the new button, and create a standard JavaBean.
19) Name the bean DepartmentsLov.
20) Via the class editor, add 2 private scope fields DepartmentId and DepartmentName with String data-types, ensuring the create get/set method checkboxes are checked.
21) Make and save your changes.
22) From the navigator drag the newly created java file into the data-control palette.
UIX LOV
23) Return to the LOV webpage.
24) Your LOV page will have a lovSelect event handler something like the following:
<event name="lovSelect">
<set property="inputValue"
value="${bindings.DepartmentId.inputValue}"
target="${data.employeesEdit.DepartmentId}"/>
25) Change the lovSelect as follows:
<event name="lovSelect">
<compound>
<set property="inputValue"
value="${bindings.DepartmentId.inputValue}"
target="${data.employeesEdit.DepartmentId}"/>
<set value="${bindings.DepartmentId.inputValue}"
property="inputValue"
target="${bindings.JavaBeanDepartmentId}"/>
<set value="${bindings.DepartmentName.inputValue}"
property="inputValue"
target="${bindings.JavaBeanDepartmentName}"/>
</compound>
26) Within the UI model navigator, right-click on the top node, then create-binding, input, text field.
27) Select the AppModuleDataControl, then DepartmentView, then the DepartmentName field, and then the ok button.
28) In the UI model select the new field, then in the structure pane rename the field to DepartmentName.
29) Within the UI model navigator, right-click on the top node, then create-binding, data, iterator.
30) Select the DepartmentsLovDataControl and name the new iterator DepartmentsJavaBeanIterator.
31) Again in the UI model navigator, right-click on the top node, then create-binding, input, text field.
32) Select the DepartmentsLovDataControl then departmentId field, then the ok button.
33) In the UI model select the new field, then in the structure pane rename the field to JavaBeanDepartmentId.
34) Again in the UI model navigator, right-click on the top node, then create-binding, input, text field.
35) Select the DepartmentsLovDataControl then departmentName field, then the ok button.
36) In the UI model select the new field, then in the structure pane rename the field to JavaBeanDepartmentName.
UIX input-only-form
37) Return to the main employeesEdit UIX form.
38) Your UIX page will have a lovUpdate event handler something like the following:
<event name="lovUpdate">
<null/>
39) Change the lovUpdate as follows:
<event name="lovUpdate">
<compound>
<set value="${bindings.JavaBeanDepartmentId.inputValue}"
property="inputValue"
target="${bindings.DepartmentId}"/>
<set value="${bindings.JavaBeanDepartmentName.inputValue}"
property="inputValue"
target="${bindings.DepartmentName}"/>
</compound>
</event>
40) Repeat steps 29 through 36 for this page.
41) Within the UIX page find the entries for the departmentId LOV, and the DepartmentName. They should look something like the following:
<messageLovInput id="${bindings.DepartmentId.path}"
model="${bindings.DepartmentId}"
destination="lovWindow1.uix"/>
<messageTextInput model="${bindings.DepartmentName}"
columns="10"/>
42) Modify these 2 entries as follows:
<messageLovInput id="DepartmentId"
model="${bindings.DepartmentId}"
destination="lovWindow1.uix"
partialRenderMode="multiple"
partialTargets="DepartmentId DepartmentName"/>
<messageTextInput id="DepartmentName"
model="${bindings.DepartmentName}"
columns="10"/>
43) Finally delete the original DepartmentId messageTextInput field, leaving the DepartmentId messageLovInput.
Testing
44) Open your UIX input-only-form.
45) Call the LOV and change the department for an existing employee record.
46) Return to the employees page and note that the department ID and name have changed.
47) Commit your changes.
48) With your favourite data inspection tool (a'la Toad), check that the employee record's department ID has been appropriately saved to the database.
<The End>
Phew!