Bound Values in OA framework - II

Lets take a closer look at the interface DataObject.

From javadoc

The DataObject interface provides an extremely simple API for retrieving arbitrarily structured data. All "queries" are based simply on a selection string. It is entirely up to an implementation of this interface to define the syntax for these strings.

It has only one method.

public java.lang.Object selectValue(RenderingContext context, java.lang.Object select)


OA Framework creates a named DataObject for each data source and then caches the DataObject on oracle.cabo.ui.RenderingContext. A data source is identified by the view usage name set on the web bean. OA Framework then gets the value from the DataObject using the view attribute on the bean as a lookup key.

OAWebBean.getValue() >> delegates to OADataBoundValue.getValue(RenderingContext context) and passes rendering context as parameter >> which lookups DataObject from
renderingcontext based on view usage name setup in the web bean and calls that DataObject.selectValue () with view attribute name as lookup key.

For a table bean OA fraemwork creates DataList which is a list of DataObject. ReneringContext.getCurrentDataObject() will return the DataObject for the current processing
row.

So code in OADataBoundValue.getValue(RenderingContext context) will look like

  DataObject dataobject = renderingcontext.getCurrentDataObject(); 
if(dataobject == null)   {
     // will return view usage name
     String s = ((OAWebBeanData)mOAWebBean).getDataObjectName();
     if(s != null)     {  
      // first parameter is name space URI
        dataobject = renderingcontext.getDataObject(
                             "oracle.apps.fnd.framework",
                              s);
     }
 }
   // gets view attribute name  
String s1 = ((OAWebBeanDataAttribute)mOAWebBean).getDataAttributeName();  
if(s1 != null && !s1.equals(""))    
   return dataobject.selectValue(renderingcontext, s);

Most of the above things are just good to know kind of information. So lets take a look at this in OAF developer perspective on how to use this.

Typical use cases are
(a) To programaticaly bind a web bean property like "Rendered" or "Prompt" etc to a view object
(b) To programaticaly set fire action event parameters.

STEP 1: Find out whether the web bean takes BoundValue as parameter for the property/attribute.
STEP 2: Find the right BoundValue implementation to pass it to the web bean. For example for the USE CASE (a) we will use OADataBoundValueViewObject and for USE CASE (b) we will use OADataBoundValueFireActionURL.
STEP 3: Determine the parameters required to be passed to the BooundValue constructor.
STEP 4: Create the corresponding BoundValue object and pass it to the setAttribute() method.

Example 1: (Based on USE CASE a: To set prompt of web bean to a view object)

OAMessageStyledTextBean mTextBean =
     (OAMessageStyledTextBean)webBean.findChildRecursive("TextID");
OADataBoundValueViewObject promptBV =
   new OADataBoundValueViewObject(mTextBean, "VoAttribute");
mTextBean.setAttributeValue(
       oracle.cabo.ui.UIConstants.PROMPT_ATTR, promptBV);

Example 2: (Based on USE CASE b: To set fire action event programaticaly )

        OAMessageStyledTextBean b =
        (OAMessageStyledTextBean)createWebBean(
                                    pageContext,
                                    MESSAGE_STYLED_TEXT_BEAN,
                                    "NUMBER",
                                    "TextID");       
    b.setViewUsageName("ViewusageName");
    b.setViewAttributeName("ViewAttributeName");
    Hashtable params = new Hashtable(1);
    OADataBoundValueFireActionURL fireEventBV = new
      OADataBoundValueFireActionURL(webBean,"{$ViewAttributeName}");
    params.put("FireEventParameter",fireEventBV);
    b.setFireActionForSubmit("fireEvent",null,
                             params,false,false);