Develop Reference

JSF datatable and lists [duplicate]

I'm using Primefaces in a JSF 2 application. I have a <p:dataTable>, and instead of selecting rows, I want the user to be able to directly execute various actions on individual rows. For that, I have several <p:commandLink>s in the last column.
My problem: how can I pass a row ID to the action started by the command link so that I know which row to act on? I tried using an <f:attribute>:
<p:dataTable value="#{bean.items}" var="item">
...
<p:column>
<p:commandLink actionListener="#{bean.insert}" value="insert">
<f:attribute name="id" value="#{item.id}" />
</p:commandLink>
</p:column>
</p:dataTable>
But it always yields 0 - apparently the row variable f is not available when the attribute is rendered (it works when I use a fixed value).
Anyone has an alternative solution?

As to the cause, the <f:attribute> is specific to the component itself (populated during view build time), not to the iterated row (populated during view render time).
There are several ways to achieve the requirement.
If your servletcontainer supports a minimum of Servlet 3.0 / EL 2.2, then just pass it as an argument of action/listener method of UICommand component or AjaxBehavior tag. E.g.
<h:commandLink action="#{bean.insert(item.id)}" value="insert" />
In combination with:
public void insert(Long id) {
// ...
}
This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by #ViewScoped.
You can even pass the entire item object:
<h:commandLink action="#{bean.insert(item)}" value="insert" />
with:
public void insert(Item item) {
// ...
}
On Servlet 2.5 containers, this is also possible if you supply an EL implementation which supports this, like as JBoss EL. For configuration detail, see this answer.
Use <f:param> in UICommand component. It adds a request parameter.
<h:commandLink action="#{bean.insert}" value="insert">
<f:param name="id" value="#{item.id}" />
</h:commandLink>
If your bean is request scoped, let JSF set it by #ManagedProperty
#ManagedProperty(value="#{param.id}")
private Long id; // +setter
Or if your bean has a broader scope or if you want more fine grained validation/conversion, use <f:viewParam> on the target view, see also f:viewParam vs #ManagedProperty:
<f:viewParam name="id" value="#{bean.id}" required="true" />
Either way, this has the advantage that the datamodel doesn't necessarily need to be preserved for the form submit (for the case that your bean is request scoped).
Use <f:setPropertyActionListener> in UICommand component. The advantage is that this removes the need for accessing the request parameter map when the bean has a broader scope than the request scope.
<h:commandLink action="#{bean.insert}" value="insert">
<f:setPropertyActionListener target="#{bean.id}" value="#{item.id}" />
</h:commandLink>
In combination with
private Long id; // +setter
It'll be just available by property id in action method. This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by #ViewScoped.
Bind the datatable value to DataModel<E> instead which in turn wraps the items.
<h:dataTable value="#{bean.model}" var="item">
with
private transient DataModel<Item> model;
public DataModel<Item> getModel() {
if (model == null) {
model = new ListDataModel<Item>(items);
}
return model;
}
(making it transient and lazily instantiating it in the getter is mandatory when you're using this on a view or session scoped bean since DataModel doesn't implement Serializable)
Then you'll be able to access the current row by DataModel#getRowData() without passing anything around (JSF determines the row based on the request parameter name of the clicked command link/button).
public void insert() {
Item item = model.getRowData();
Long id = item.getId();
// ...
}
This also requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by #ViewScoped.
Use Application#evaluateExpressionGet() to programmatically evaluate the current #{item}.
public void insert() {
FacesContext context = FacesContext.getCurrentInstance();
Item item = context.getApplication().evaluateExpressionGet(context, "#{item}", Item.class);
Long id = item.getId();
// ...
}
Which way to choose depends on the functional requirements and whether the one or the other offers more advantages for other purposes. I personally would go ahead with #1 or, when you'd like to support servlet 2.5 containers as well, with #2.

In JSF 1.2 this was done by <f:setPropertyActionListener> (within the command component). In JSF 2.0 (EL 2.2 to be precise, thanks to BalusC) it's possible to do it like this: action="${filterList.insert(f.id)}

In my view page:
<p:dataTable ...>
<p:column>
<p:commandLink actionListener="#{inquirySOController.viewDetail}"
process="#this" update=":mainform:dialog_content"
oncomplete="dlg2.show()">
<h:graphicImage library="images" name="view.png"/>
<f:param name="trxNo" value="#{item.map['trxNo']}"/>
</p:commandLink>
</p:column>
</p:dataTable>
backing bean
public void viewDetail(ActionEvent e) {
String trxNo = getFacesContext().getRequestParameterMap().get("trxNo");
for (DTO item : list) {
if (item.get("trxNo").toString().equals(trxNo)) {
System.out.println(trxNo);
setSelectedItem(item);
break;
}
}
}

Thanks to this site by Mkyong, the only solution that actually worked for us to pass a parameter was this
<h:commandLink action="#{user.editAction}">
<f:param name="myId" value="#{param.id}" />
</h:commandLink>
with
public String editAction() {
Map<String,String> params =
FacesContext.getExternalContext().getRequestParameterMap();
String idString = params.get("myId");
long id = Long.parseLong(idString);
...
}
Technically, that you cannot pass to the method itself directly, but to the JSF request parameter map.

property not found for method in JSF [duplicate]

I am building a JSF application. I defined the GUI and did the select statements query the database using select.
Now I must do the insert statements, but I don't know how to read the value of a JSF input component like <h:inputText> and send it to my bean which performs the insert.
Should <h:inputText> value be mapped through faces-config.xml, so I can have it in my Java code?

You need to put all <h:inputXxx>/<h:selectXxx> components in a <h:form> and bind their value attribute to a bean property via an EL expression like #{bean.property}, backed by a getter/setter pair. When properly set, JSF will automatically set the values in the bean when the form is submitted via a <h:commandXxx> component in the very same form. You can specify a bean action method in action attribute of the <h:commandXxx> component via an EL expression like #{bean.action}, which points to the bare method action(). All submitted values are available right away there the usual Java way.
Given this JSF form example with one input field and one select field:
<h:form>
<h:inputText value="#{bean.text}" required="true" />
<h:selectOneMenu value="#{bean.choice}" required="true">
<f:selectItem itemValue="#{null}" />
<f:selectItem itemValue="One" />
<f:selectItem itemValue="Two" />
<f:selectItem itemValue="Three" />
</h:selectOneMenu>
<h:commandButton value="submit" action="#{bean.submit}" />
<h:messages />
<h:outputText value="#{bean.result}" />
</h:form>
The following bean prints the submitted values to the stdout, proving that JSF has already set the values long before the moment you access it in the action method.
package com.example;
import javax.inject.Named;
import javax.enterprice.context.RequestScoped;
#Named // Use #javax.faces.bean.ManagedBean on outdated environments.
#RequestScoped // Use #javax.faces.bean.RequestScoped on outdated environments.
public class Bean {
private String text;
private String choice;
private String result;
public void submit() {
result = "Submitted values: " + text + ", " + choice;
System.out.println(result);
}
public String getText() {
return text;
}
public void setText(String text) {
this.text = text;
}
public String getChoice() {
return choice;
}
public void setChoice(String choice) {
this.choice = choice;
}
public String getResult() {
return result;
}
}
That's all. Turning the regular form into an ajax form is a matter of nesting a <f:ajax> in the command component as below.
<h:commandButton value="submit" action="#{bean.submit}">
<f:ajax execute="#form" render="#form" />
</h:commandButton>
You can find another example and valuable links at bottom of our JSF wiki page.
Do note that whatever you intend to do with the submitted values is beyond the responsibility of JSF. For example, manipulating it, passing into another class, saving it in database, etc. None of this all is related to JSF. It has as being a HTML form based framework already done its job of providing you the submitted values in flavor of usable Java variables. The remainder is up to you.
To investigate the next step, you should at this point just be doing as if you've already a bunch of prepared / hardcoded variables instead of a whole JSF based user interface. For example, in order save to the values in a database, people usually use a business service layer framework like EJB which in turn uses a persistence layer framework like JPA. Some people even use "plain vanilla" JDBC for that. For more links to concrete examples, start here: JSF Controller, Service and DAO.

how can I send a value from my view to my bean using primefaces?

I am sending values to my view from my bean and from my view to my bean, everything is fine if I work with event such as "acitonListener" but now I want to send the user to other page (with a navigation rule, it works perfect) when I click on a button, but before of that I want to set in my bean one value, how can I do this?
I am doing something like this
<p:commandButton value="Send" id="sendButton" action="#{myBean.myMethod}"
update=":form:growTop" >
</p:commandButton>
Before of that there is only a table with <h:outputText/> with values from my bean, any way to do this?
Thanks

action="#{myBean.myMethod(myParameter)}
The above method expression will send myParameter to the myMethod function in your backing bean:
public void myMethod(String myParameter) {
// ...
}
You can also send the user to the next page by returning a valid navigation outcome from your action method:
public String myMethod(String myParameter) {
// ...
return "myPage?faces-redirect=true";
}
In your concrete case if there is a backing bean value which is printed out:
<h:outputText value=#{myBean.myParameter}/>
the following action
<p:commandButton value="Send" id="sendButton" action="#{myBean.myMethod(myParameter)}
update=":form:growTop" >
</p:commandButton>
will pass myParameter to your action method.
In order to get the expected behavior with primefaces datatable use at least #ViewScoped backing bean behind your table values.

Binding process occurs before action is taken in JSF 2

I'm using PrimeFaces with JSF 2.0, I have this layout:
<h:panelGroup layout="block" id="panelGroup" binding="#{bean.boundPg}" />
<p:commandButton value="Update" action="#{bean.updateMe}" update="panelGroup" />
in which, the bean is SessionBean. By using log4j to debug I found out that the binding process called getBoundPg before executing the action updateMe. So the view is always out-of-date.
Do you know why and how to reverse that order? Thanks!
------------- Edit ---------------
I'm making a web app for a quiz game.
<h:panelGroup layout="block" id="pgContents" binding="#{bean.boundContents}" />
<p:commandButton value="Prev page" action="#{bean.prevPage}" update="pgContents" />
<p:commandButton value="Next page" action="#{bean.nextPage}" update="pgContents" />
pgContents contains many h:pannelGroups, each sub-group contains a label showing the content of a quiz, a h:inputText for the player to give their answer. Because of some reasons, I had to generate the children of pgContents programmatically.
The Prev page and Next page buttons will retrieve the prev/next group of quiz
Below is the bean (getters & setters are skipped)
#ManagedBean(name = "bean")
#SessionScoped
public class LessonHelper {
private int currentPage;
private HtmlPanelGroup boundContents;
public void prevPage() {
// decrease currentPage
// fetch contents
// add children for boundContents (label, inputText)
}
// nextPage() is similar
}
My problem is that, when I click the Prev/Next button, the getter getBoundContents is called first in binding process, and the prevPage()/nextPage() is called later, which cause the content always out-of-date.

Because this is the natural way, as you can see in this wonderful tutorial by BalusC: http://balusc.blogspot.com/2006/09/debug-jsf-lifecycle.html
Tell me exactly what do you want to do, show what's inside that bean and a solution to your problem will be found!

Primefaces dataTable with embedded commandLink

I'm trying to embed a Primefaces commandLink and call an action listener from a link inside a column of a Primefaces dataTable. Is this not possible? The "Test" onclick alert gets fired but it never makes it to my bean's method.
<p:dataTable var="location" value="#{adminBean.locations}">
<p:column headerText="Options">
<p:commandLink value="delete" actionListener="#{admin.deleteLocation}" onclick="alert('test')"/>
</p:column>
</p:dataTable>
bean code:
public void deleteLocation(ActionEvent e){
//delete logic here...
}

This is possible. Your actionListener should be called. Keep in mind that the p:commandButton uses ajax by default. So you should use the update attribute in order to define the components to be updated.
However, I don't know if this affects the actionListener. Did you try it with action instead of actionListener?
Here is an example how I got it working:
<p:commandLink action="#{spc.selectPatient(item)}"
ajax="false"
value="Open"/>
The bean method looks as follows:
public String selectPatient(Patient p) {
// do something
// return some outcome
}