Hi i have an "fieldset" tag in my jsf page
now i need to conditional add an "disabled" attribute
i have a solution, but it is very ugly:
<h:outputText escape="false" value="<fieldset disabled='disabled'>" rendered="#{surveysHandler.surveyRunning}" />
<h:outputText escape="false" value="</fieldset>" rendered="#{surveysHandler.surveyRunning}" />
is there a cool jsf 2.2 method?
Yes, there is a cool new JSF 2.2 way to achieve this!
You can make the fieldset a JSF 2.2 passthrough element and pass it a map of attributes like this:
<fieldset jsf:id="fieldset">
<f:passThroughAttributes value="#{customerBean.params}"/>
</fieldset>
The prefix jsf is for the new JSF 2.2 namespace http://xmlns.jcp.org/jsf. If an HTML tag has any attribute in this namespace, JSF will convert it to a real JSF component in the component tree. Therefore it is possible to use f:passThroughAttributesto add attributes coming from a map in a managed bean.
The getter for the params property could look like this (you can add attributes based on any condition in the bean):
public Map<String, String> getParams() {
HashMap<String, String> params = new HashMap<String, String>();
if (disabled) {
params.put("disabled", "disabled");
}
return params;
}
For further information about passthrough attributes and elements, have a look at my blogpost about HTML5 friendly markup with JSF 2.2.
Related
Following on from the response by the legendary BalusC to this post:
How to programmatically or dynamically create a composite component in JSF 2
Had I sufficient points I would attach a comment to that post -- but I don't have sufficient points .
Problem as follows.
I'm trying to set up a commandButton which adds a JSF composite component dynamically to an xhtml file. With the intention that clicking it multiple times will put multiple instances of the component on the page.
So I have a button on an XHTML file:
<h:commandButton action="#{assessingController.addQuestion}" value="Add a Question"></h:commandButton>
Which calls a method on AssessingController:
public void addQuestion() {
UIComponent parent = null;
includeCompositeComponent(parent, "http://xmlns.jcp.org/jsf/composite/components", "questionComposite", "someId");
}
UIComponent parent = null; -- because it has to be instantiated or referenced somehow, before being passed into includeCompositeComponent . But as noted below - making it null might be causing the null pointer exception, (so what should I do instead?)
includeCompositeComponent method is as per the JSF 2.2 method referred to by BalusC in the above post:
public void includeCompositeComponent(UIComponent parent, String taglibURI, String tagName, String id) {
FacesContext context = FacesContext.getCurrentInstance();
UIComponent composite = context.getApplication().getViewHandler()
.getViewDeclarationLanguage(context, context.getViewRoot().getViewId())
.createComponent(context, taglibURI, tagName, null);
composite.setId(id);
parent.getChildren().add(composite);
}
When I click on the commandButton, logs as follows:
javax.faces.el.EvaluationException: java.lang.NullPointerException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:101)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315) ...
Caused by: java.lang.NullPointerException
at controllers.AssessingController.includeCompositeComponent(AssessingController.java:123)
AssessingController.java:123 is this line:
parent.getChildren().add(composite);
Composite is not null (checked that).
So, obviously perhaps, - parent is null and that's where the problem is.
So how can I better reference UIComponent parent to begin with?
Do I need to make it refer to something on the xhtml file? I'm presuming it needs some kind of a placeholder which will serve as the parent(?). Right now all there is on the xhtml page is the commandButton.
Thank you all.
The parent is supposed to represent the component where you'd like to include the composite component in.
Imagine that you ultimately want to end up with this plain XHTML representation:
<h:panelGroup id="questions">
<your:questionComposite />
</h:panelGroup>
You should then supply exactly that <h:panelGroup> component as parent.
<h:form>
<h:commandButton ... action="#{bean.addQuestion}" />
</h:form>
<h:panelGroup id="questions" />
public void addQuestion() {
UIComponent parent = context.getViewRoot().findComponent("questions");
// ...
}
Or, by passing the concrete component itself:
<h:form>
<h:commandButton ... action="#{bean.addQuestion(questions)}" />
</h:form>
<h:panelGroup id="questions" binding="#{questions}" />
public void addQuestion(UIComponent parent) {
// ...
}
Unrelated to the concrete problem: there's a thinking/design mistake here. You should rather use an <ui:repeat><your:compositeComponent> and then feed from a #ViewScoped bean to the <ui:repeat> a dynamically sized list of entities representing the composite's model value.
<h:form>
<h:commandButton ... action="#{bean.addQuestion}" />
</h:form>
<ui:repeat value="#{bean.questions}" var="question">
<your:questionComposite value="#{question}" />
</ui:repeat>
private List<Question> questions;
public void addQuestion() {
questions.add(new Question());
}
Anytime you need to deal with raw UIComponent instances in a backing bean, take a pause and carefully research or ask if you're really doing things the right way. Perhaps it belongs in a backing component instead, or could just be done with pure XHTML.
See also:
How to dynamically add JSF components
How does the 'binding' attribute work in JSF? When and how should it be used?
JSF 1.2 DataTable
I know how to remove the row from datatable writing following code.
jsp
<h:graphicImage id="deleteRowBtn_img" url="../../images/table_icon_delete.gif" style="cursor:pointer" alt="Delete Row">
<a4j:support id="deleteRowBtn" event="onclick" actionListener="#{mnpAction.deleteMultiNoPortRow}" reRender="multiNoPortTable" oncomplete="resetViewConfigs();"/>
</h:graphicImage>
action bean
public void deleteMultiNoPortRow(ActionEvent ae) {
{
int index = abcBean.getDataTable().getRowIndex();
mnpBean.getMultiNoPortingList().remove(index);
}
}
But i want to know is there any other way to remove row from datatable in JSF1.2.
Any help regarding this appreciate!!!!!!
You can get the same appearance and functionality by using an a4j:commandButton and its image attribute instead of <h:graphicImage> as below.
<a4j:commandButton image="../../images/table_icon_delete.gif" actionListener="#{mnpAction.deleteMultiNoPortRow}"/>
If your <h:graphicImage> is in a column of the table, you can pass the var of the table to a method in your baking bean and remove that element from the list without having to use the row index. Here use action instead of actionListener.
<a4j:support id="deleteRowBtn" event="onclick" action="#{mnpAction.remove(myVar)}".../>
In mnpAction bean (Assuming the type of your list is T)
public void remove(T s) {
mnpBean.getMultiNoPortingList().remove(s);
}
Edit:
Since you are using JSF1.2 you may not use #{mnpAction.remove(myVar)}" to pass parameters to the bean if you don't like to upgrade your EL library.
I want to display java arraylist into JSF page. I generated arraylist from database. Now I want to display the list into JSF page by calling the list elements index by index number. Is it possible to pass a parameter to bean method from an EL expression in JSF page directly and display it?
You can access a list element by a specific index using the brace notation [].
#ManagedBean
#RequestScoped
public class Bean {
private List<String> list;
#PostConstruct
public void init() {
list = Arrays.asList("one", "two", "three");
}
public List<String> getList() {
return list;
}
}
#{bean.list[0]}
<br />
#{bean.list[1]}
<br />
#{bean.list[2]}
As to parameter passing, surely it's possible. EL 2.2 (or JBoss EL when you're still on EL 2.1) supports calling bean methods with arguments.
#{bean.doSomething(foo, bar)}
See also:
Our EL wiki page
Invoke direct methods or methods with arguments / variables / parameters in EL
I however wonder if it isn't easier to just use a component which iterates over all elements of the list, such as <ui:repeat> or <h:dataTable>, so that you don't need to know the size beforehand nor to get every individual item by index. E.g.
<ui:repeat value="#{bean.list}" var="item">
#{item}<br/>
</ui:repeat>
or
<h:dataTable value="#{bean.list}" var="item">
<h:column>#{item}</h:column>
</h:dataTable>
See also:
How iterate over List<T> and render each item in JSF Facelets
Hi Have this Wierd Issue in which I am using a Composite Component which I wrote and I get values from the previous use of the backing bean of the CC (the componentType bean)
I don't know how to describe this better than just show the code.
I'll try to be brief about it and cut the redundant parts:
This is the Composite Component definition:
<cc:interface componentType="dynamicFieldGroupList">
<cc:attribute name="coupletClass" />
<cc:attribute name="form" default="#form"/>
<cc:attribute name="list" type="java.util.List" required="true"/>
<cc:attribute name="fieldNames" type="java.util.List" required="true" />
</cc:interface>
<cc:implementation>
<h:dataTable value="#{cc.model}" var="currLine">
<h:column>
<h:outputText id="inner_control_component" value="Inner Look at currLine:#{currLine}"/>
</h:column>
</h:dataTable>
</cc:implementation>
The CC bean defintion:
#FacesComponent(value = "dynamicFieldGroupList")
// To be specified in componentType attribute.
#SuppressWarnings({ "rawtypes", "unchecked" })
// We don't care about the actual model item type anyway.
public class DynamicFieldGroupList extends UIComponentBase implements
NamingContainer
{
private transient DataModel model;
#Override
public String getFamily()
{
return "javax.faces.NamingContainer"; // Important! Required for
// composite components.
}
public DataModel getModel()
{
if (model == null)
{
model = new ListDataModel(getList());
}
return model;
}
private List<Map<String, String>> getList()
{ // Don't make this method public! Ends otherwise in an infinite loop
// calling itself everytime.
return (List) getAttributes().get("list");
}
}
And the use code:
<ui:repeat var="group" value="#{currentContact.detailGroups}">
<h:panelGroup rendered="#{not empty group.values}">
<h:outputText id="controlMsg" value=" list:#{group.values}" /><br/><br/>
<utils:fieldTypeGroupList list="#{group.values}"
fieldNames="#{group.fields}" coupletClass="utils" />
</h:panelGroup>
</ui:repeat>
The text of id controlMsg displays the correct values in #{group.values} while the control output inside the component of id inner_control_component shows the values from the previous use.
The values are correct the first time...
I guess it's a fundemental error in use of a CC bean, otherwise it could be a bug with MyFaces 2.1 (Which I'm using)
The explanation for this behaviour is simple: there's only one component definied in the view. So there's also only one backing component with one model. Since the model is lazily loaded on first get, the same model is been reused in every iteration of a parent iterating component.
The <ui:repeat> doesn't run during view build time (as JSTL does), but during view render time. So there are physically not as many components in the view as items which are iterated by <ui:repeat>. If you were using <c:forEach> (or any other iteration tag which runs during view build time), then the composite component would have behaved as you'd expect.
You would like to change the way how the datamodel is kept in the backing component. You would like to preserve a separate datamodel for each iteration of a parent iterating component. One of the ways is to replace the model property as follows:
private Map<String, DataModel> models = new HashMap<String, DataModel>();
public DataModel getModel() {
DataModel model = models.get(getClientId());
if (model == null) {
model = models.put(getClientId(), new ListDataModel(getList()));
}
return model;
}
See also:
What's the view build time?
The problem described here is an old known isse in JSF, hidden by the usage of composite components. It is so important and so difficult, that instead answer here I create a detailed answer in a blog entry for this one: JSF component state per row for datatables
To keep this answer short, I'll say to you it is not a bug in MyFaces 2.1. Please use 2.1.1, because that is a quick bug fix version of 2.1.0. In JSF 2.1 there is a new property for h:dataTable called rowStatePreserved, and this scenario is just one case where "this little baby" becomes useful. Just replace ui:repeat with h:dataTable and add rowStatePreserved="true". That will do the trick. If you need to manipulate the model (add or remove rows) you can use tomahawk t:dataTable and t:dataList, but you will have to take an snapshot version for now. Note this is new stuff not available in any different JSF framework an the moment (JUN 2011).
If you need more info, keep tuned with MyFaces Team on Twitter or ask to the experts on MyFaces Users and Dev Mailing Lists.
I have a managed bean under ViewScope. It has an instance variable inside it.
MetaData object has a inputItem object List.
#ManagedBean
#ViewScoped
public class ConBean implements Serializable {
private MetaData metadata;
#PostConstruct
#SuppressWarnings("unchecked")
public void init() throws IOException {
this.metadata = new MetaData ();
}
public void proc(){
List<InputItem> inputs= new ArrayList<InputItem>();
inputs.add(***** code to populate the inputItem List);
//after populating, inputs added to the metadata
metadata.setInputs(inputs);
}
//getters & setters
}
in my JSF , input list is populated inside a UI repeat.
<div id="inputplaceholder">
<ui:repeat value="#{conBean.metaData.inputs}" var="content">
</ui:repeat>
</div>
the div inputplaceholder is periodically updated using a richfaces poll.
<a4j:poll id="poll" interval="12000" action="#{conBean.proc}"
execute="#form" render="inputplaceholder"/>
The problem that I have is even though inputItems are set to the metaData object correctly inside the proc() method, when the view is rendered/partially updated, it doesn't get highlighted in the UI. so partial update takes no effect. I tried moving
this.metadata = new MetaData ();
inside the proc method but had no luck.
any ideas and help is highly appreciated.
thanks ...
Did the partial render really take place? This is impossible. There is namely no JSF component with the ID inputplaceholder. You assigned it to a plain HTML <div> element. Replace it by a fullworthy JSF component:
<h:panelGroup layout="block" id="inputplaceholder">
Also, since you used a relative ID in the render attribute, it will only scan for components in the same parent naming container component. The <ui:repeat> is such one, however the component with the desired ID is placed outside it. You'd like to use an absolute ID instead. Assuming that it's inside a <h:form> with a fixed ID:
<h:form id="myform">
<h:panelGroup layout="block" id="inputplaceholder">
...
then you should be referencing it in the render attribute as follows
render=":myform:inputplaceholder"