Using one ViewObject for Global Lookup Data

A user on the OTN JDeveloper & ADF forum asked how to use one ViewObject, which holds lookup data of different areads, as LOV source. This post shows how to do this.

UPDATE:
In part 2 I added a use case which shows how to use a global lookup view object to initialize a LOV component before a page loads and show the selected lookup data.

Before we begin we have to setup the data for the the sample we build to work with. For this we add two tables to the HR schema (or any other schema you have access to). One, GENERALLOOKUP, hols lookup data, which is grouped ba a type attribute.

General Lookup Data

General Lookup Data


As we see the type column is used to group the data into different areas. The task is to use one view object which queries this table as base for model driven LOVs. To show this we need another table which we use to enter values selected by a LOV for the area from the type column.
Test Table and Data

Test Table and Data

BlogGeneralLokup 018

Scripts to create the tables and insert some data into them are provided together with the sample workspace in the file ‘setup_db.sql’. After we setup the table and the data we create entity objects and view objects like we normally do. Once the eo and vo are created, we add a view criteria which we use to select a specific type of lookup data from the GENERALLOOKUP table.

ViewCriteria to Select Lookup Data

ViewCriteria to Select Lookup Data

The view criteria has one bind variable which we later use to distinguish the different groups of lookup data. Now we can setup the lov for the attributes of the LookupTestView view object. We show this for the TitleId attribute:

Setup LOV for  TitleId Attribute

Setup LOV for TitleId Attribute


Create LOV VO

Create LOV VO


BlogGeneralLokup 003 View Accessors
rename the view object to TiltelookupView andshuttle it to the selected area
Select the GeneralLookupView

Select the GeneralLookupView


Click the edit button on the top right
Edit the LOV View

Edit the LOV View


The vital part is that we switch to the ‘View Object’ node and select the view criteria ‘TypeLookupViewCriteria’ and set the bind variable to the desired type. In this case it is ‘TITLE’
BlogGeneralLokup 006 Edit View Accessor_ TitlelookupView

Select ViewCriteria and Bind Variable

Select ViewCriteria and Bind Variable

Once the list source is setup we select the id of the list source (TitlelookupView) as ‘List Attribute’ and set the TitleId as ‘View Attribute’ for the id. Finally select the ‘UI Hint’ tab and shuttle the ‘Data’ attribute to the ‘Selected’ side. The ‘Data’ attribute of the TitlelookupView will then shown in the listbox on the UI.
BlogGeneralLokup 008 Create List of Values

BlogGeneralLokup 009 Create List of Values

Setup LOV for TitleId

Setup LOV for TitleId

This concludes the implementation for the TitleId attribute. The other attributes (GenderId, PositionId and WeekdayId) are done hte same way. Only change the bind variable ‘bindType’ to the type area you are generating the LOV for.

The gallery above shows the running application. You can download the sample workspace which was build JDeveloper 11.1.1.7.0 and using the HR schema from the ADF EMG Samples side BlogStaticVOLov_V2.zip. You can open the workspace using JDev 11.1.1.6.0 without a problem. If you are asked if you like to migrate the workspace to 11.1.1.6.0 answer with Yes.

UPDATE:
In part 2 I added a use case which shows how to use a global lookup view object to initialize a LOV component before a page loads and show the selected lookup data.

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5 thoughts on “Using one ViewObject for Global Lookup Data

    • Hi, no performance issue I know of. As the data is EO based there will be a cache for the data.
      If you see a problem provide a test case…

      Timo

  1. Hi Timo,

    Thanks for pointing out this post. I implemented this approach but my doubt was in term of CACHE and using this viewObject in a sharedApplicationModule. Would this approach be the same, less or more effective than creating many viewObjects based on the same EO and overriding the query itself to just use the set of data that I really need. My lookup table comes from Oracle Apps and it has 200699 rows. So I thought that creating few viewObjects restricting to the rows I need would be more effective since they will be cached by the EO and query will be executed just once in the sharedAppModule, but I would like your input on this.

    Regards

    Alejandro Tovar Lanz

    • If you build many vo based on the same eo they share the same eo cache. There should no difference between the two approaches in this case. As long the the lookup table has the right index defined the retrieval of the rows should be no problem.

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