Custom selection listener for af:listView, Invoke selectionListener programmatically

In the last post (Better UI for data collection using af:listView, Enable selection in ADF Faces List component ) about af:listView, we saw that how can we present data collection in a better way using af:listView and enable selection using EL (same as used for af:table)

Now in this post i will describe about defining custom selection listener for af:listView
Suppose you have to do some task on selection of an item in list other than making it current row, for this you have to override default selection listener and define own custom selection listener in managed bean
So next step is to define a method in managed bean for handling selection event of af:list view

• Select af:listView, goto properties and click on edit menu of selectionListener property and create a method in managed bean








• now see what we have to do in custom selection listener, first invoke default selection listener EL (#{bindings.Departments1.collectionModel.makeCurrent}) to make selected row as current and then get current row from iterator as selected row is now current row
  See the managed bean code -



//Import these packages

import javax.el.ELContext;
import javax.el.ExpressionFactory;
import javax.el.MethodExpression;
import javax.el.ValueExpression;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;

import oracle.jbo.Row;

import org.apache.myfaces.trinidad.event.SelectionEvent;   


 /**
     * Programmatic invocation of a method that an EL evaluates to.
     *
     * @param el EL of the method to invoke
     * @param paramTypes Array of Class defining the types of the parameters
     * @param params Array of Object defining the values of the parametrs
     * @return Object that the method returns
     */
    public static Object invokeEL(String el, Class[] paramTypes, Object[] params) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        ELContext elContext = facesContext.getELContext();
        ExpressionFactory expressionFactory = facesContext.getApplication().getExpressionFactory();
        MethodExpression exp = expressionFactory.createMethodExpression(elContext, el, Object.class, paramTypes);

        return exp.invoke(elContext, params);
    }

    /**
     * Programmatic evaluation of EL.
     *
     * @param el EL to evaluate
     * @return Result of the evaluation
     */
    public static Object evaluateEL(String el) {
        FacesContext facesContext = FacesContext.getCurrentInstance();
        ELContext elContext = facesContext.getELContext();
        ExpressionFactory expressionFactory = facesContext.getApplication().getExpressionFactory();
        ValueExpression exp = expressionFactory.createValueExpression(elContext, el, Object.class);

        return exp.getValue(elContext);
    }

    /**Custome Selection Listener for af:listView
     * @param selectionEvent
     */
    public void listSelectionListener(SelectionEvent selectionEvent) {
        //invoke this EL to set selected row as current row, if it is not invoked then first row will be current row
        invokeEL("#{bindings.Departments1.collectionModel.makeCurrent}", new Class[] { SelectionEvent.class }, new Object[] {
                 selectionEvent });
        // get the selected row , by this you can get any attribute of that row
        Row selectedRow = (Row) evaluateEL("#{bindings.Departments1Iterator.currentRow}");
        FacesMessage msg = new FacesMessage(selectedRow.getAttribute("DepartmentName").toString());
        msg.setSeverity(FacesMessage.SEVERITY_INFO);
        FacesContext.getCurrentInstance().addMessage(null, msg);
    }



• Now run application and check

Download Sample ADF Application here
Thanks , Happy Learning :)

Better UI for data collection using af:listView, Enable selection in ADF Faces List component

af:listView is a new component introduced in Jdev 12C to show tabular data (rows of a collection), it uses same configuration as af:table
In this post i will be describing- how to create af:listView using ADF business component and  how we can enable selection in af:listView

Let's start
How to create af:listView using ADF BC-

• Created a Fusion Web Application and prepared model using Departments table of HR Schema




drop Departments viewObject on page from DataControl as ADF List View






Configuration Wizard for List is opened, set the appropriate layout




Set the value binding that we want to show on page




After this we can customize layout on page also, we can change color, style width etc;
see XML source of af:listView-



<af:listView value="#{bindings.Departments1.collectionModel}" var="item"
                             emptyText="#{bindings.Departments1.viewable ? 'No data to display.' : 'Access Denied.'}"
                             fetchSize="#{bindings.Departments1.rangeSize}" id="lv1">
                    <af:listItem id="li1">
                        <af:panelGroupLayout layout="horizontal" id="pgl1">
                            <f:facet name="separator">
                                <af:spacer width="10" id="s1"/>
                            </f:facet>
                            <af:outputFormatted value="#{item.bindings.DepartmentId.inputValue}" id="of1"
                                                inlineStyle="font-weight:bold;font-size:medium;color:red;">
                                <af:convertNumber groupingUsed="false"
                                                  pattern="#{bindings.Departments1.hints.DepartmentId.format}"/>
                            </af:outputFormatted>
                            <af:outputFormatted value="#{item.bindings.DepartmentName.inputValue}" id="of2"
                                                inlineStyle="font-weight:bold;font-size:small;color:navy;"/>
                        </af:panelGroupLayout>
                        <af:panelGroupLayout id="pgl2">
                            <af:outputLabel value="Manager id" id="ol1"/>
                            <af:outputFormatted value="#{item.bindings.ManagerId.inputValue}" id="of3">
                                <af:convertNumber groupingUsed="false"
                                                  pattern="#{bindings.Departments1.hints.ManagerId.format}"/>
                            </af:outputFormatted>
                            <af:spacer width="10" height="10" id="s2"/>
                            <af:outputLabel value="Location Id" id="ol2"/>
                            <af:outputFormatted value="#{item.bindings.LocationId.inputValue}" id="of4">
                                <af:convertNumber groupingUsed="false"
                                                  pattern="#{bindings.Departments1.hints.LocationId.format}"/>
                            </af:outputFormatted>
                        </af:panelGroupLayout>
                    </af:listItem>
                </af:listView>



and how it looks on page- hmmm better than af:table





• By default adf listView doesn't support selection, you can see Selection property is set to none. it shares same configuration as af:table , you can see that value property is bound to #{bindings.Departments1.collectionModel} and attributes are populated using variable reference of this collection





• To enable selection just set Selection to single and in selectionListener property of list set #{bindings.Departments1.treeModel.makeCurrent}







• Now Run this application and check, single selection is enabled

 Thanks, happy learning :)

ADF Basics: Set multiple LOV's on attribute and conditionally switch using LOV Switcher

This post is about a very basic and common use case
Suppose we have to show different values in our List depending on some condition but all values must be stored in same attribute so for this type of requirement ADF BC framework provides concept of LOV Switcher
Framework allows us to define multiple LOV on same attribute, I hope you all know about defining LOV(List of Values) so move ahead and see how to use lov switcher

 See the implementation part-

• Created a Fusion Web Application and a viewObject to show LOV on viewport (Used dual to create view object for this example , you can use use your own)








• Created 2 more viewObject to apply LOV on first viewObject's attribute, One ViewObject is for Departments and other one is for Employees






• Open dual viewObject select LovAppl attribute and goto ListOfValues tab and add both LOV
  For Department - DepartmentId is List Attribute and DepartmentName will be shown on UI




For Employees- EmployeeId is List Attribute and FirstName,LastName will be shown on UI






• Now click on green plus icon of List Of Values Switcher and add a transient attribute , this will be further used to switch lov on base of some condition





• So created LovSwitcher attribute , and remember this switcher attribute value should be one of the LOV Name that are applied on attribute.
  Here i am using a condition - if LovType attribute of Dual viewObject is 'D' the LovAppl should show Departments Lov and if it is 'E' then LovAppl should show Employees Lov
  For this i have written expression for lov switcher attribute
  LovType=='D' ? 'LOV_LovAppl' : LovType=='E' ? 'LOV_LovAppl1' : null





• Now run Application Module and check it

Thanks , Happy Learning :)