Sunday Jun 24, 2012

How-to dynamically filter model-driven LOV

Often developers need to filter a LOV query with information obtained from an ADF Faces form or other where. The sample below shows how to define a launch popup listener configured on the launchPopupListener property of the af:inputListOfValues component to filter a list of values.

<af:inputListOfValues id="departmentIdId"
   value="#{bindings.DepartmentId.inputValue}"                                      
   model="#{bindings.DepartmentId.listOfValuesModel}"
   launchPopupListener="#{PopupLauncher.onPopupLaunch}" … >      
   …
</af:inputListOfValues>

A list of values is queried using a search binding that gets created in the PageDef file of a view when a lis of value component gets added. The managed bean code below looks this search binding up to then add a view criteria that filters the query.

public void onPopupLaunch(LaunchPopupEvent launchPopupEvent) {
  BindingContext bctx = BindingContext.getCurrent();
  BindingContainer bindings = bctx.getCurrentBindingsEntry();
  JUCtrlListBinding lov = 
       (JUCtrlListBinding)bindings.get("DepartmentId");
  ViewCriteriaManager vcm = 
       lov.getListIterBinding().getViewObject().getViewCriteriaManager();          
  //make sure the view criteria is cleared
  vcm.removeViewCriteria(vcm.DFLT_VIEW_CRITERIA_NAME);
  //create a new view criteria
  ViewCriteria vc = 
         new ViewCriteria(lov.getListIterBinding().getViewObject());
  //use the default view criteria name
  //"__DefaultViewCriteria__"
  vc.setName(vcm.DFLT_VIEW_CRITERIA_NAME);
  //create a view criteria row for all queryable attributes
  ViewCriteriaRow vcr = new ViewCriteriaRow(vc);
  //for this sample I set the query filter to DepartmentId 60. 
  //You may determine it at runtime by reading it from a managed bean
  //or binding layer 
  vcr.setAttribute("DepartmentId", 60);
  //also note that the view criteria row consists of all attributes 
  //that belong to the LOV list view object, which means that you can
  //filter on multiple attributes
  vc.addRow(vcr);           
  lov.getListIterBinding().getViewObject().applyViewCriteria(vc);
} 

Note: Instead of using the vcm.DFLT_VIEW_CRITERIA_NAME name you can also define a custom name for the view criteria.

Thursday Jun 21, 2012

Partial Submit vs. Auto Submit

Partial Submit

ADF Faces adds the concept of partial form submit to JavaServer Faces 1.2 and beyond. A partial submit actually is a form submit that does not require a page refresh and only updates components in the view that are referenced from the command component PartialTriggers property. Another option for refreshing a component in response to a partial submit is call AdfContext.getCurrentInstance.addPartialTarget(component_instance_handle_goes_here)in a managed bean. If a form contains required fields that the user left empty invoking the partial submit, then errors are shown for each of the field as the full form gets submitted.

Autosubmit

An input component that has its autosubmit property set to true also performs a partial submit of the form. However, this time it doesn't submit the entire form but only the component that triggers the submit plus components referenced it in their PartialTriggers property.

For example, consider a form that has three input fields inpA, inpB and inpC with autosubmit=true set on inpA and required=true set on inpB and inpC.

use case 1: Running the view, entering data into inpA and then tabbing out of the field will submit the content for inpA but not for inpB and inpC. Further more, none of the required field settings on inpB and inpC causes an error.

use case 2: You change the configuration of inpC and set its PartialTriggers property to point to the ID of component inpA. When rerunning the sample, entering a value into inpA and tabbing out of the field will now submit the inpA and inpC fields and thus show an error for the missing required value on inpC.

Internally, using autosubmit=true on an input component sets the event root to just this field, which good to have in case of dependent field validation or behavior. The event root can extended to include other components by using the Partial Triggers property on these components to point to the input field that has autosubmit=true defined.

PartialSubmit vs. AutoSubmit

Partial submit set on a command component submits the whole form and leaves it to the developer to decide which UI component is refreshed in response. Client side required field validation (as well as the server side equivalent) is not disabled by executed in this scenario. Setting immediate=true on the command item to skip validation doesn't help as it would also skip the model update.

Auto submit is a functionality on the input components and also performs a partial form submit. However, in addition an event root is defined that narrows the scope for the submitted data and thus the components that are validated on the request.

To read more about this topic, see: http://docs.oracle.com/cd/E23943_01/web.1111/b31973/af_lifecycle.htm#CIAHCFJF

Thursday Feb 23, 2012

How-to define a default action for page fragments

The af:form component has a DefaultCommand property that, when set to the component Id of a command component like af:commandButton invokes the associated command action when the enter key is pressed anywhere in this form. However, if the form fields are contained in a page fragment exposed in a region then using the DefaultCommand property may not be an option as it is difficult to predict the command button id and its surrounding naming containers.

A solution to this is to use JavaScript on the UI input components that, when the Enter key is pressed virtually press a button within the page fragment (note that the af:form element belongs to the parent page and that you can only have a single af:form component per browser page)

Let's assume a page fragment with a single input text component and a command button to press:

<af:panelFormLayout id="pfl1">
  <f:facet name="footer">
     <af:commandButton text="Print Field Value" id="cb1" partialSubmit="true"                                            
                       clientComponent="true" action="#{View1Bean.onButtonPressed}"/>
   </f:facet>
   <af:inputText label="Enter Field" id="it1" binding="#{View1Bean.inputTextField}">
      <af:clientListener method="onFieldEnterKey" type="keyUp"/>
   </af:inputText>  
</af:panelFormLayout>

The command button is bound to a managed bean action method. By default, the action method is invoked when users press the command button. However, with the JavaScript shown next, this can be simulated and mapped to the Enter key press in the text field.

<?xml version='1.0' encoding='UTF-8'?>
<jsp:root xmlns:jsp="http://java.sun.com/JSP/Page" version="2.1"
          xmlns:af=http://xmlns.oracle.com/adf/faces/rich
          xmlns:f="http://java.sun.com/jsf/core">

<af:resource type="javaScript">
   //function called by the client listener

  function onFieldEnterKey(inputEvent){
    if (event.getKeyCode() == AdfKeyStroke.ENTER_KEY) {
      //get the input text component from the event            
      var inputTextField = inputEvent.getSource();
      //the button is relative to the input text field so
      //relative search will do with no worrying about naming
      //containers
      var defaultButton = inputTextField.findComponent('cb1');
      //perform a partial submot
      var partialSubmit = true;
      AdfActionEvent.queue(defaultButton,partialSubmit);
      //Enter key does not need to go to server as we
      //queued a new event
       event.cancel();
   }
}
</af:resource>

For JavaScript to work, note the use of the af:clientListener on the input text field and the use of the clientComponent="true" configuration on the button.

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