OAF: How to create a PVO and use that for Spel Binding in Oracle Application Framework

In this post I will give an example to show how to create a PVO ("Application Properties" View Object) and use the attributes to change the properties of the bean dynamically. I will give same method to set the PVO Attribute values. This method can be used when there is only 1 attribute to be set or if there are multiple attributes.

Scenario:
I have created 2 tables in the page (say Table1 and Table2). I need to show Table1 when the page loads and hide Table2. Based on some conditions, I will need to change the Tables in screen dynamically. 

• Create a PVO with 2 attributes (1 for each table). Set the value of the attribute appropirately.
• Use Spel binding to associate the attribute to the table. Refer: OAF: Spel Binding

Create PVO with 2 attributes (I have created one additional Id column also, which can be set as the Key Attribute). Make sure that you set the Updatable property to 'Always'.

Add this VO to the Application Module and then add the below methods in the AMImpl.

 import oracle.jbo.domain.Number;  

 public void intializeXXCustomPVO()  
 {  
      OAViewObjectImpl xxCustomPVO = getXXCustomPVO1();  
      if(xxCustomPVO.getRowCount() == 0 )  
      {  
           Row xxCustomPVORow = xxCustomPVO.createRow();  
           xxCustomPVORow.setNewRowState(Row.STATUS_INITIALIZED);        
           xxCustomPVORow.setAttribute("Id",new Number(-1));  
           xxCustomPVO.insertRow(xxCustomPVORow);  
      }  
 }  

 public void setXXCustomPVOValues(String[] name,String[] val)  
 {  
      OAViewObjectImpl xxCustomPVO = getXXCustomPVO1();  
      xxCustomPVO.setRangeSize(-1);  
      Row row = xxCustomPVO.getRowAtRangeIndex(0);  
      for(int i = 0; i < name.length; i ++)  
      {  
           if("Y".equals(val[i]))  
           {  
                row.setAttribute(name[i],Boolean.TRUE);  
           }  
           else  
           {  
                row.setAttribute(name[i],Boolean.FALSE);  
           }  
      }  
 }  

Write the below code in the processRequest of the Controller. This will create a Row in the PVO and initialize the PVO attributes.

 import java.io.Serializable;  
 import oracle.apps.fnd.framework.server.OAApplicationModuleImpl;  

 OAApplicationModuleImpl appModule = (OAApplicationModuleImpl)pageContext.getApplicationModule(webBean);  
 appModule.invokeMethod("intializeXXCustomPVO");
  
 String[] name = {"RenderAttr1","RenderAttr2"};  
 String[] val  = {"Y","N"};
  
 Serializable[] params = {name, val};  
 Class[] paramTypes    = {String[].class, String[].class};
  
 appModule.invokeMethod("setXXCustomPVOValues", params, paramTypes);  

Write the below code in the processFormRequest based on your condition.Change the values of the val[] appropriately, based on your use case.

 OAApplicationModuleImpl appModule = (OAApplicationModuleImpl)pageContext.getApplicationModule(webBean);
  
 String[] name = {"RenderAttr1","RenderAttr2"};  
 String[] val  = {"N","Y"};
  
 Serializable[] params = {name, val};  
 Class[] paramTypes    = {String[].class, String[].class};
  
 appModule.invokeMethod("setXXCustomPVOValues", params, paramTypes);  

You can use the below syntax to set the Rendered property of the bean.
   ${oa.XXCustomPVO1.RenderAttr1}

   ${oa.XXCustomPVO1.RenderAttr2}


Feel free to point out if anything is missing/wrong in this blog.

OAF: Spel Binding

Simplest Possible Expression Language (SPEL) - An industry-standard expression language included in the JSP Standard Tag Library (JSTL)

For selected properties, OA Framework supports the use of SPEL expressions to quickly bind the property to an underlying data source that provides the property's value. For example, you could bind the Rendered property of a button to a view object attribute to ascertain whether it should be hidden or shown when the page renders.

The SPEL syntax for this property looks like:

   ${oa.<ViewInstanceName>.<ViewAttributeName>}

       

      eg:-  ${oa.XXViewObject1.ViewAttrName}

If you are working with a table-in-table or HGrid that uses view links, you need to modify your SPEL syntax as shown: ${oa.current.viewAttrName}. The inclusion of current keyword lets you say "get the value from whatever row BC4J is using to render the current row" since you won't know how to access the view objects and row sets created dynamically for these complex components.

To add a VOAttribute value in a link 

eg: OA.jsp?OAFunc=XXX_FUNC&VENDOR_SITE_ID={@VendorSiteId}&SUPP_NAME={@SupplierName}

You can also use SPEL based on the security grant. The below expression will return false if <FunctionName> is granted to the current user/responsibility, otherwise true. 
   ${oa.FunctionSecurity.<FunctionName>}

If you want to pass a attribute for the form submission and if you want to encrypt the parameter, you can add the expression as below in the parameters property window:
   ${oa.encrypt.<ViewInstanceName>.<ViewAttributeName>} 

From 12.2, there is more support: OAF: EL (Expression Language)

Feel free to point out if anything is missing/wrong in this blog.