Navigation using managed beans [duplicate] - jsf

This question already has answers here:
commandButton/commandLink/ajax action/listener method not invoked or input value not set/updated
(12 answers)
Closed 6 years ago.
i am working on a simple project in JSF 2.2 but i have some problem navigating between some pages. In the project i have a general template and all the views are template clients of that general template.
this is the view that i have troubles with:
<h:body>
<ui:composition template="./LayoutGeneral.xhtml">
<ui:define name="content">
<p:commandButton value="Registrar Comunidad" action="#{comunidadBean.irRegisterView}"/>
</ui:define>
</ui:composition>
</h:body>
In the action of the commandButton i call a method from the managed bean (Thar managed bean have other method that i call to change the page and they work fine, but this method doesnt):
(Managed Bean)
#ManagedBean
#SessionScoped
public class ComunidadBean {
private String idComunidad;
private String idPresidente;
private String calle;
private int numero;
private int nVecinos;
#EJB
private ComunidadDAO ejb;
public String register(){
if(ejb.realizaRegistro(this)){
return "principalView";
} else{
FacesMessage fm = new FacesMessage ("No se pudo registrar");
FacesContext.getCurrentInstance().addMessage("msg", fm);
return null;
}
}
public String irRegisterView(){
return "registroCView";
}
}
So the method "register" works fine and the page change but the method "irRegisterView" doesnt navigate to "registroCView" page.
Does someone has any idea of what it is happening?
Thanks!

I can' comment, so I write this as an answer.
I see that your bean is SessionScoped. You need to implement Serializable because a SessionScoped bean is passivating after a time.
do you have a form in LayoutGeneral.xhtml? If not, this code will never works because a commandButton needs be within a form.
why you call the method as a property? In JSF 2.2 and EL 2.3, you can call methods like this: #{comunidadBean.isRegisterView()}.
Is some exception thrown when click the button? If do, paste the stack trace.

Related

How to hold values in a CDI conversion scope?

I try to add a object to a LinkedList in a #ConversationScoped backing bean.
#Named
#ConversationScoped
public class CategoryController implements Serializable{
...
private List<Category> selectedCategories = new LinkedList<Category>();
...
#PostConstruct
public void initNewMember() {
conversation.begin();
newCategory = new Category();
loadExistingCategories();
}
...
}
I want to send an ajax request with new objects (of type category). They should simply be added to the linked list.
this.selectedCategories.add(newParentCategory);
With the ajax render attribute <f:ajax render="allSelectedCategories"/> I immediately render the output text to render the object list.
<h:outputText id="allSelectedCategories" value="#{categoryController.selectedCategories}" />
And yes, the object I clicked is displayed, but the previously clicked objects are gone.
The values do not serialize/persist in memory during my "conversation". What do I need to do to make that conversion scope temporarily persist the values of the ajax calls?
I really want to get used to CDI and abandon the ManagedBean path for this project (e.g. #ViewScoped), despite the fact that it works like a charm.
Also, I cannot reproduce the following tutorial on CDI Conversation Scope. I simply cannot debug into the initConversation by adding
<f:event listener="#{categoryController.initConversation}"
type="preRenderView"></f:event>

<f:ajax listener="#{bean.selectPlan}" call to #PostConstruct before execute the selectPlan method [duplicate]

This question already has an answer here:
#ViewScoped calls #PostConstruct on every postback request
(1 answer)
Closed 6 years ago.
I have a check box in my application and I want to call selectPlan method to execute when user select the check box
But when ever I select the check box it call the #PostConstruct method before the selectPlan method.
This leads to unwanted calls to back end as I have written some functions to populate data when page load in the #PostConstruct
<td>
<h:selectBooleanCheckbox value="#{plan.checked}">
<f:ajax listener="#{planOverlay.selectPlan}" render=":overlayForm:myTable"/>
</h:selectBooleanCheckbox>
</td>
Below is the bean class
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
#ManagedBean(name = "planOverlay")
#ViewScoped
public class PlanOverlayBean extends OverlayBean {
#PostConstruct
public void init() {
super.init();
loadPlansFrom_DB();
}
public void selectPlan(AjaxBehaviorEvent event) throws Exception {
getOverlay().getService().setSelectedPlan(rowdata);
}
}
To avoid that case,we should check if it is postback or ajaxRequest.
If your bean is viewScoped,you can add below code to your post-construct method.
Maybe it is not the best case but it works.
Also you can use JSF 2 PreRenderViewEvent for some initialization for bean.
if (!FacesContext.getCurrentInstance().isPostback()) {
if (!FacesContext.getCurrentInstance().getPartialViewContext().isAjaxRequest()) {
//Some initialization
}
}
You should make your bean session scoped, so the #PostConstruct gets called only once per session. When bean is request scoped, like yours is judging by the behavior, it is created for each request which results in init() getting called also for each request.
EDIT
The suggestion was based on the assumption that the bean is request scoped, and that init() should be called once per session/view. OP's comment proved the assumption wrong.

Single page applications with ajax [duplicate]

This question already has answers here:
How to ajax-refresh dynamic include content by navigation menu? (JSF SPA)
(3 answers)
Closed 1 year ago.
I'm relatively new to JSF and trying to learn how current JSF 2 applications are designed. I've seen reference to single page applications that use ajax. Can someone fill me in on some of the techniques used and / or point me to a model or book? The books I've seen (JSF Complete Reference etc.) are good for basic tech issues but I can't find a source for current design techniques.
Thanks
Dave
In order to implement your Single Page Application, you should state which piece of your page should be rendered. This can be accomplished making use of a boolean flag such as create, edit, list, and so on. For instance, see the following (Just relevant code)
<h:body>
<h:form rendered="#{userController.stateManager.create}">
<h:panelGroup rendered="#{not empty facesContext.messageList or userController.stateManager.failure}">
<!--render error message right here-->
</h:panelGroup>
<div>
<label>#{messages['br.com.spa.domain.model.User.name']}</label>
<h:inputText value="#{user.name}"/>
</div>
<h:commandButton action="#{userController.create}">
<f:ajax execute="#form" render="#all"/>
<f:actionListener type="br.com.spa.web.faces.listener.StateManagerActionListener" />
<f:setPropertyActionListener target="#{userController.stateManager.create}" value="true"/>
<f:setPropertyActionListener target="#{userController.user}" value="#{user}" />
</h:commandButton>
</form>
</h:body>
Notice that our form will be rendered when a flag create is true - See second line above. To wrap our flags, we create a classe named StateManager as follows
/**
* I am using lombok, which takes care of generating our getters and setters. For more info, please refer http://projectlombok.org/features/index.html
*/
#Setter #Getter
public class StateManager {
private boolean create;
private boolean edit;
private boolean list;
}
Now, because we are using only a single page, we should use a ViewScoped managed bean, which keep our managed bean scoped active as long as you are on the same view - Is it a single page application, right ? So, no navigation. With this in mind, let's create our managed bean.
#ManagedBean
#ViewScoped
public class UserController implements StateManagerAwareManagedBean {
private #Inject UserService service;
private #Getter #Setter stateManager = new StateManager();
private #Getter #Setter List<User> userList = new ArrayList<User>();
private #Getter #Setter User user;
#PostConstruct
public void initialize() {
list();
}
public void create() {
service.persist(user);
stateManager.setCreate(false);
stateManager.setList(true);
stateManager.setSuccess(true);
}
public void edit() {
service.merge(user);
stateManager.setEdit(false);
stateManager.setList(true);
stateManager.setSuccess(true);
}
public void list() {
userList = service.list();
stateManager.setList(true);
}
}
For each action method, we define which piece of our page should be rendered. For instance, consider that our form was processed, covering all of JSF lyfecycle, which implies that their values was successfully converted and validated, and our action method invoked. By using as example our create action method - see above -, we set its create flag as false because our form was converted and validated, so we do not need to show it again (Unless you want). Furthermore, we set both list and success flag as true, which indicates that the list of our page should be rendered and our form was successfully processed - You could use this flag to show something like "User created" such as bellow
<h:panelGroup rendered="#{userController.stateManager.success}">
#{messages['default.created.message']}
</h:panelGroup>
Now, let's discuss which piece of our page should be rendered when it is called for the first time. Maybe you do not know but a void method annotated with #PostConstruct will be called first. So we define which piece of our page should be rendered. In our example, we call list method, which sets its list flag as true and populate a backing list.
#PostConstruct
public void initialize() {
list();
}
Finally, let's review the following order nested within h:commandButton
<h:commandButton action="#{userController.create}">
<f:ajax execute="#form" render="#all"/>
<f:actionListener type="br.com.spa.web.faces.listener.StateManagerActionListener" />
<f:setPropertyActionListener target="#{userController.stateManager.create}" value="true"/>
<f:setPropertyActionListener target="#{userController.user}" value="#{user}" />
</h:commandButton>
First of all, you should call an ActionListener - here called StateManagerActionListener - which takes care of resetting any StateManager - code bellow. It must be called first before any other setPropertyActionListener designed to control any flag because the order defined within h:commandButton is the order in which they will be called. keep this in mind.
public class StateManagerActionListener implements ActionListener {
public void processAction(ActionEvent e) throws AbortProcessingException {
Map<String,Object> viewMap = FacesContext.getCurrentInstance().getViewRoot().getViewMap();
for(Map.Entry<String,Object> entry: viewMap.entrySet()) {
if(entry.getValue() instanceof StateManagerAwareManagedBean) {
((StateManagerAwareManagedBean) entry.getValue()).setStateManager(new StateManager());
}
}
}
}
StateManagerAwareManagedBean - used in our ViewScoped Managed bean -, which allows that we reset any StateManager of any ManagedBean instead of resetting one by one in our ActionListener, is defined as follows
public interface StateManagerAwareManagedBean {
StateManager getStateManager();
void setStateManager(StateManager stateManager);
}
Second, after defining our ActionListener, we use a setPropertyActionListener which set the flag which controls the enclosing piece of the view as true. It is needed because our form is supposed to be not converted and validated. So, in our action method, we set this flag as false as discussed before.
A couple of notes
User is marked as a RequestScoped ManagedBean so that it can not be injected into a ViewScoped one using a ManagedProperty because its scope is shother. To overcome this issue, i set its value by using a <f:setPropertyActionListener target="#{userController.user}" value="#{user}"> - See our form
Our example use JEE features which need a proper Application Server. For more info, refer http://docs.oracle.com/javaee/6/tutorial/doc/
ManagedBean can play different roles such as a Controller, DTO and so on. When it play a role of a Controller, i prefer suffix its name with Controller. For more info, refer http://java.dzone.com/articles/making-distinctions-between

c:set for bean properties

I'm looking for some piece of code for setting a property in a JSF managed bean. My first idea was something like that:
<c:set var="#{loginBean.device}" value="mobil"></c:set>
That means I want to set the attribute device to the value "mobil" without a button have to been clicked.
Yes, you can use c:set for this purpose.
<c:set value="mobil" target="#{loginBean}" property="device" />
Doc: http://docs.oracle.com/cd/E17802_01/j2ee/javaee/javaserverfaces/2.0/docs/pdldocs/facelets/c/set.html
However, setting a static value rarely makes sense. You might consider to set a default value directly in your managed bean class. Also in terms of maintainability since you can handle constants better in the Java code than in the view layer.
I think you want the JSF tag child tag setPropertyActionListener. You can set this as a child tag in any ActionComponent.
<h:anyActionComponent id="component1">
<f:setPropertyActionListener target="#{loginBean.device}" value="mobil" />
</h:anyActionComponent>
UPDATE:
I originally misunderstood the users problem. They have a page, and they want a property to be set when the page loads. There is a couple ways to do this, but both are a little different. If you want to set a property to a value after every postback then you can use the #PostConstruct annotation on a ManagedBean method.
#PostConstruct
public void initializeStuff() {
this.device = "mobil";
}
Now if I have a ViewScoped or SessionScope bean that needs to be initialized with a default value just once when the page loads then you can set a phase lifecycle event that will run after every postback and check to see if the page should be initialized or not.
mah.xhmtl:
<f:event listener="#{loginBean.initialize()}" type="preRenderView" />
LoginBean:
public void initialize() {
if (this.device == null)
this.device = "mobil";
}
I am not able to Comment: If you need the value to be ready on page on load, you could use Managed Bean to directly initialize value or use its constructor or #PostConstruct to do the same.
#ManagedBean
#ResquestScoped
public class LoginBean {
private String device = "some value";
//Using Constructor
public LoginBean() {
device = getvalueFromSomewhere();
}
//Using PostConstruct
#PostConstruct
public void init() {
device = getvalueFromSomewhere();
}
}
Instead of setting the value in the xhtml file you can set via another ManagedBean. For instance if you have managedBean1 which manages page1.xhtml and managedBean2 which manages page2.xhtml. If page1.xhtml includes page2.xhtml like:
<ui:include src="page2.xhtml"/>
in managedBean1 you can have at the top
#ManagedProperty(value = "#{managedBean2}")
private ManagedBean2 managedBean2;
and in the PostConstruct
#PostConstruct
public void construct() {
managedBean2.setProperty(...);
}
worked for me anyway...

JSF preload list for datatable in page [duplicate]

This question already has an answer here:
How and when should I load the model from database for JSF dataTable
(1 answer)
Closed 7 years ago.
I'm using EJB and JSF. I made a jsp simple page with a button "get list". When it's clicked, a managed bean method is called that sets the list, which is then displayed in the jsp with the dataTable tag.
The question is, how can I pre load this list/dataTable on page load without having to click the button?
This is the method that's called through the button action on the jsp:
public String retrieveList() {
items = facade.getAllItem();
return "";
}
this is the part of the jsp:
<h:dataTable value="#{mybean.items}" var="sup"
binding="#{mybean.dataTable}"
rowClasses="oddRow, evenRow"
styleClass="tableStyle"
headerClass="tableHeader"
columnClasses="column1, column2, column1, column1, column1, column1">
You can add a method init with #postConstruct
#PostConstruct
public void init(){
items = facade.getAllItem();
}
This will return the items only on bean creation ,
Annotate the method with #PostConstruct and get rid of return value.
#PostConstruct
public void retrieveList() {
items = facade.getAllItem();
}
This way the method will be executed immediately after construction of the bean and injection of all #EJB dependencies. In the JSF page you just have to bind to #{bean.items} the usual way.

Resources