ui:include dependent on viewParam - java

I have a page where I want to include a part of the page (footer in this instance) dependant on values given from a view parameter.
I have my ViewScoped backing bean initializing on preRenderView
<f:metadata>
<f:viewParam name="racecode" value="#{displayResults.racecode}" />
<f:event type="preRenderView" listener="#{displayResults.init}" />
</f:metadata>
This queries the database to get the name of the footer to be included. This then, is used in this fashion :
<h:panelGroup id="customFooter" display="block">
<ui:include src="#{displayResults.customFooter}" />
</h:panelGroup>
This always gives me a missing page. But if I enter the page name manually it works. Same if I replace the ui:include with an h:outputText.
I understand that it has something to do with the phases of JSF and that at the time the ui:include is done, the value is not set yet. (reading up and better understanding the phases is something on my TODO list).
The question remains. How can I get something of the sort done. Have a bean use the viewParam, query the database and use that value in a ui:include?

#wemu has already explained the cause. The <ui:include src> is evaluated before init() method is called. His proposed <f:phaseListener> solution is however clumsy.
Just use #ManagedProperty/#PostConstruct on a #RequestScoped bean.
#ManagedProperty("#{param.racecode}")
private String racecode;
#PostConstruct
public void init() {
// ...
}

PreRenderView listeners are called within the RenderResponsePhase, before components are rendered BUT AFTER the TagHandlers are called. This means that TagHandlers will NOT see data initialized within a PreRenderView event.
If you are using a <ui:include value="#{myBean.myViewId}" /> to dynamically switch an include you can't use a PreRenderView event listener to set the myViewId property of myBean.
If you need to do that use a <f:phaseListener>.

Related

Elegant handling of attributes without a session bean

I'm working on an application using JSF 2.0 and Richfaces 4, that consists of many tables that display elements and of course, the usual View/Edit/Delete options. After some SO browsing and Google search I've decided to post a question because the answers I found did not solve my problem.
Right now, and going straight to the point, my application is having issues when handling certain attributes that are stored in request beans and, on certain points, are lost due to successive requests.
For example, when I want to edit an object, the object is sent (f:propertyActionListener) to a request bean that displays the data on a form, then it is discarded as that request ends. When saving, a new object is created and the attributes on the form are setted to it and the item gets saved instead of updated, since it has no id (JPA + Hibernate).
I've investigated many options and this is what I've did so far and the results:
f:param + h:link or h:commandLink: With #ManagedProperty the param is null, and I can't find it on the Context to look it up through JNDI.
f:setPropertyActionListener + h:commandLink + Request Bean: Works... but I'm losing some data. The form that displays the data has some conditionally rendered fields and I can't hold that info, so the form is messed if the validation phase finds invalid data.
f:viewParam + h:commandLink + View Scoped Bean: Weird stuff here. This one doesn't directly work because the bean seems to get discarded before rendering the form, because the form is rendered with no information since the bean is clean.
Using a session bean: Works like a charm, but I don't want to make a session bean for every form just because I'm still learning things about the JSF lifecycle, I want to do it the proper way.
If I want to keep the Request session approach, is there a way to store a parameter (either an object or a plain string) and obtain later on a request bean?.
Dunno if this helps but I'm using a master page through ui:insert and ui:define.
Use a view scoped bean. It should work. The problems which you describe there suggests that you're binding it to JSTL tags or id or binding attributes. You should not do that on a view scoped bean. See also #ViewScoped fails in tag handlers. Another possible cause is that you're using CDI's #Named to manage the bean instead of JSF's #ManagedBean. That would also explain why #ManagedProperty doesn't work in one of your attempts as it also requires the bean to be managed by JSF's #ManagedBean.
As to the master-detail page approach, use a <h:link> with <f:param> in the table page to create view/edit links in the master page.
E.g. user/list.xhtml
<h:dataTable value="#{userList.users}" var="user">
<h:column>#{user.id}</h:column>
<h:column>#{user.name}</h:column>
<h:column>
<h:link value="Edit" outcome="edit">
<f:param name="id" value="#{user.id}" />
</h:link>
</h:column>
</h:dataTable>
The bean can be just request scoped.
Then, in the defail page, which is in this case an edit page, use <f:viewParam> to convert, validate and set the id as User.
E.g. user/edit.xhtml
<f:metadata>
<f:viewParam name="id" value="#{userEdit.user}"
converter="#{userConverter}" converterMessage="Bad request. Unknown user."
required="true" requiredMessage="Bad request. Please use a link from within the system." />
</f:metadata>
<h:messages />
<h:link value="Back to all users" outcome="users" />
<h:form id="user" rendered="#{not empty userEdit.user}">
<h:inputText value="#{userEdit.user.name}" required="true" />
...
<h:commandButton value="Save" action="#{userEdit.save}">
<f:ajax execute="#form" render="#form" />
</h:commandButton>
</h:form>
Use a #ViewScoped bean to hold the data, service and action methods:
#ManagedBean
#ViewScoped
public class UserEdit {
private User user;
#EJB
private UserService service;
public String save() {
service.save(user);
return "users";
}
// Getter+setter.
}

Pass a parameter inside <f:event listener="#{myBean.retrieveData(#{})">

I need to populate one datatable using database dynamically in which i need to call a retieveData() method and pass a id to criteria my result inside the method. The parameter that is to be passed is coming from another bean by #{anotherBean.id}. My question is how to pass this parameter inside the method...?
Following is what i am trying to do...
<f:metadata>
<f:event listener="#{myBean.retrieveData(#{anotherBean.id)}" type="preRenderComponent" id="fevent"/>
</f:metadata>
You can pass it through attribute.
Here is what I do on JSF:
<f:metadata>
<f:event listener="#{myBean.retrieveData}" type="preRenderView" id="fevent"/>
<f:attribute name="myid" value="#{anotherBean.id)" />
</f:metadata>
Meanwhile the managed bean (myBean) is as follow:
public void retrieveData(ComponentSystemEvent event) {
String id = (String) event.getComponent().getAttributes().get("myid");
}
Make sure not to use '()' when calling the managed bean's method on listener of f:event tag.
Basically
<f:metadata>
<f:event listener="#{myBean.retrieveData(anotherBean.id)}" type="preRenderComponent" id="fevent"/>
</f:metadata>
should do. But why don't you inject anotherBean into myBean and retrieve id in your Java code? It is usually better to keep this kind of logic in your Java code rather than view - xhtml file in this case.

Conditionally rendered button, design, calling an action

JFS1.2 + Richfaces 3.3
Situation is as follows:
JSP page renders conditionally one or another panelGroup.
Within each panelGroup there are couple setters and one command button.
Each of two panelGroups uses own bean for setting and performing action.
On the top of a page there's selectOneRadio with (obvious) two items - coresponding tow options of conditional rendering.
Page renders properly, switcher causes to render appropriate panel.
Case is, commands buttons doesn't call an action.
I know what's going on - when I click a button to call action dom is regenerated, but the value that hold my decision to display particular panel doesn't exist anymore. The button is not recreated, action is not fired.
Technically:
<h:selectOneRadio value="#{reportType}">
<f:selectItem itemLabel="x" itemValue="x"/>
<f:selectItem itemLabel="y" itemValue="y"/>
<a4j:support event="onclick" reRender="xPanel, yPanel/>
</h:selectOneRadio>
<h:panelGrid id="xPanel "columns="2" rendered="#{reportType eq 'x'}">
<...some setters>
<... commandbutton>
</h:panelGrid>
<h:panelGrid id="yPanel "columns="2" rendered="#{reportType eq 'y'}">
<...some setters>
<... commandbutton>
</h:panelGrid>
Question is, how to design the page to obtain proper rendering and actions?
For now, I created additional session bean that holds switching value (x|y), but that desing smells bad for me...
RichFaces 3.3 offers the <a4j:keepAlive> tag which does basically the same as Tomahawk's <t:saveState> and JSF2 #ViewScoped. Add the following line somewhere in your view:
<a4j:keepAlive beanName="#{bean}" />
This will keep the bean alive as long as you're returning null or void from action(listener) methods.
See also:
JSF 1.2: How to keep request scoped managed bean alive across postbacks on same view?

h:commandLink not working when inside a list

I have a problem with RichFaces and creating lists of links. If you attempt to use any type of commandLink inside a list (I've tried ui:repeat and rich:list) the action on that link is not called. I've also tried commandButton and the a4j variations of those. I'm using JSF 2, RichFaces 4 on Jboss 6.
<rich:list var="venue" value="#{searchManager.results}" type="definitions" stateVar="status">
<h:form>
<h:commandLink value="CLICK IT" immediate="true" action="#{score.selectVenue}" />
</h:form>
</rich:list>
The position of the form also doesn't matter.
<h:form>
<rich:list var="venue" value="#{searchManager.results}" type="definitions" stateVar="status">
<h:commandLink value="CLICK IT" immediate="true" action="#{score.selectVenue}" />
</rich:list>
</h:form>
If I just have the link by itself (no list) it works.
Any help would be greatly appreciated.
When you click a command link or press a command button to submit a form, JSF will during the apply request values phase scan the component tree for the command link/button in question so that it can find the action expression associated with it, which is in your case #{score.selectVenue}.
However to be able to ever reach that, you would need to ensure that #{searchManager.results} returns exactly the same list as it did when the form was displayed. Because with an empty result list, there would be no command link/button in the view at all during the apply request values phase of the form submit.
Your #{searchManager} bean seems to be request scoped. Request scoped beans have a lifetime of exactly one request-response cycle. So when you submit the form, you'll get a brand new and another instance of the request scoped bean than it was when the form was displayed. The results property seems not to be preserved during (post)construction of the bean and thus remains empty. So JSF cannot find the command link/button in question and thus cannot find the action expression associated with it and thus cannot invoke it.
As you're using JSF2, an easy fix is to place the bean in the view scope. This way the bean will live as long as you're submitting and navigating to exactly the same view by returning null or void in action methods.
#ManagedBean
#ViewScoped
public class SearchManager {
// ...
}
See also:
commandButton/commandLink/ajax action/listener method not invoked or input value not updated

JSF2.0 Partial Render with ui:define

I'm using facelet templating and I think I'm running into an issue with ui:define and the JSF lifecycle. My template.xhtml contains a fixed menu in the header, simplified it has links like this:
<h:commandLink value="Click Me">
<f:ajax update="#{myBean.listener}" render="contentpanel"/>
</h:commandLink>
The template.xhtml also contains a ui:insert statement:
<ui:insert name="content">
<h:outputLabel value="content placeholder"/>
</ui:insert>
Now I have a content.xhtml which looks like:
<ui:composition template="template.xhtml">
<ui:define name="content">
<h:panelGroup id="contentpanel"/>
</ui:define>
</ui:composition>
So much for the introduction. When I click the commandlink 'Click Me' I'm calling my listener. This listener sets a reference in a backingbean to dynamically load the content based on the link I clicked.
This rendering is not done the first time I press the commandlink. Well it basically looks like it first does the re-render and then call the listener instead of the other way around. So when I first click, nothing seems to happen. When I click for the second time I see the content that was set for the first click. When I click for the third time I see the content of the second click.
I think it's because the ui:define view is already re-built in the 'Restore View' phase of the JSF lifecycle. Any ideas on how to overcome this?
UPDATE
Seems like my assumption was wrong. The cause of this seems to be something different. The #{myBean.listener} has a #SessionScoped #ManagedProperty which is updated after the CommandLink is clicked. The contentpanel actually loads data via the #{myBean.data} which is #RequestScoped. This #{myBean.data} did not reload the data correctly. I solved it by passing the getData() method directly to the #SessionScoped bean.
Might be a bit confusing. But my conclusion: it does work to partial render a component which is loaded via facelet templating (ui:define / ui:insert)
Seems like my assumption was wrong. The cause of this seems to be something different. The #{myBean.listener} has a #SessionScoped #ManagedProperty which is updated after the CommandLink is clicked. The contentpanel actually loads data via the #{myBean.data} which is #RequestScoped. This #{myBean.data} did not reload the data correctly. I solved it by passing the getData() method directly to the #SessionScoped bean.
Might be a bit confusing. But my conclusion: it does work to partial render a component which is loaded via facelet templating (ui:define / ui:insert)

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