ADF BC Attribute - Collection Storage Mode Property

I would like to describe one interesting property for ADF BC attribute. This property is called Storage. There are two possible values: row (default) and collection. By default attribute value is saved in row storage, but alternatively it can be saved in collection storage. ADF BC implements collection storage using map which comes from session scope. This allows to keep value even between ADF BC requests, this is ideal for transient attributes.

Sample application (ADFBCCheckboxApp.zip) implements VO transient attribute to keep checkbox value:

VO is configured for Range Paging support. While user will navigate through UI table pages - VO range paging will re-execute and this will force VO replace rows (which will result in loosing transient attribute values):

This is how it will look like. User will select checkbox and then navigate to another table page:

After navigating back - checkbox value will be lost (range paging mode will re-execute VO rowset to bring rows belonging to current page):

To force transient attribute value to stay, go to Properties window for the attribute and scroll down to the last section. Select attribute called Storage:

Change value to collection. This will force ADF BC to store value for this attribute in session map:

Transient attribute value will stay, even when VO is re-executed in range paging mode and VO rowset is refetched:

ADF 12.2.1.1 Improved Support for Programmatic View Object

ADF 12.2.1.1 brings improved support for programmatic VO creation. Such VO's are handy, when we want to base VO on alternative data source, such as PL/SQL ref cursor. In ADF 12.2.1.1 developer don't need to worry which framework methods to override, now it is enough to extend from Programmatic View Object Implementation class. This is special framework helper class, designed for programmatic VO support. See example below.

Sample application (ADF12211App.zip) is based on one regular VO, which renders employees table. Programmatic VO renders data for tag cloud component, located below table:

Steps to create programmatic VO are much more simple in ADF 12.2.1.1. Select data source option to be Programmatic in VO creation wizard:

JDEV will create VO with Java implementation classes, extended from ProgrammaticViewObjectImpl class and ProgrammaticViewRowImpl class. These classes will take care for special lifecycle required for programmatic VO behavior. See extends part:

Generated class contains getScrollableData extended method. This is the place to supply data collection for the VO. In my example, I'm creating ArrayList (VO rows) of HashMap's (one HashMap, represents row data of attribute/value pair). Attributes are populated with values and collection is returned back to the framework to manage it. Method is being called automatically by the framework. There are other methods available, to retrieve row by key, etc.:

New framework class allows to work with programmatic VO's easier and leverage framework features. I would expect it would provide better support for programmatic VO data filtering.

VO data is accessed on UI through regular binding expressions:

Initialized by ADF bindings layer: