Sending values with not working working properly in jsf

Question

When i tried to send some values with h:commandButton... i recieved null value in the bean...

my xhtml code is:

  <p:commandButton action="#{favouriteAction.setFavourite}"  value="Add as Favorite" rendered="#{favouriteBean.favouriteButton}">
  <f:setPropertyActionListener target="#{favouriteAction.ngoID}" value="#{InsertDataDaoService.ngo_id}"></f:setPropertyActionListener> 
  </p:commandButton>

In the backing bean i just tried to print the value which i passed with my command button,but it becomes null...

In favouriteAction.java(My backing Bean)

  public Integer ngoID;

public Integer getNgoID() {
return ngoID;
}


public void setNgoID(Integer ngoID) {
this.ngoID = ngoID;
}

    public String setFavourite(){

      System.out.println("Ngo id: "+ngoID);
   System.out.println("Ngo id: "+getNgoID);

    return "";
}

In console i dint get any exceptions, my o/p is

Ngo id: 0 Ngo id: 0

that is null, and it doesnt get passed..

`favouriteBean` is request scoped? It should be at least view scoped to make this `rendered="#{favouriteBean.favouriteButton}"` work properly. There are werid problems with this. — Piotr Gwiazda, Jan 19 '12 at 11:16
i have no problem in rendering the command button, its properly rendered even after that bean is request scoped. my problem is with passing an value with commandbutton.... — Karthikeyan, Jan 19 '12 at 11:22
I had serveral problems with `rendered` and button commands. Button is rendered OK but problems exits on Restore View phase. On RestoreView JSF creates new request bean with `favouriteButton` set to false and it looks like button is not rendered. Werid things happens here. Probably `setPropertyActionListener` is not created at all, because it's inside not rendered component. On update model phase `favouriteButton` is true and the button is rendered properly. But it's too late: `setPropertyActionListener` was missed. — Piotr Gwiazda, Jan 19 '12 at 12:54
@Peter: the action is invoked. So the `rendered` attribute isn't the problem. — BalusC, Jan 19 '12 at 13:19

score 1 · Answer 1 · answered Jan 19 '12 at 11:46

1

Have you checked that the value of InsertDataDaoService.ngo_id is not NULL? Try to replace it with a constant value. Does it work?

answered Jan 19 '12 at 11:46

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score 1 · Accepted Answer · edited May 23 '17 at 12:21

The <f:setPropertyActionListener> is evaluated during the request of the form submit, not during the request of displaying the form. So if its value #{InsertDataDaoService.ngo_id} is not preserved for that request, then it will fail.

You have basically 2 options:

Ensure that #{InsertDataDaoService.ngo_id} is preserved for the request of the form submit. How exactly do to that depends on the functional requirements which are not clear from the question. But generally, putting the #{InsertDataDaoService} bean in the view scope by @ViewScoped and making sure that you aren't doing any business job in the getter method should be sufficient.
Replace <f:setPropertyActionListener> by <f:param> with @ManagedProperty.
```
<p:commandButton action="#{favouriteAction.setFavourite}" value="Add as Favorite" rendered="#{favouriteBean.favouriteButton}">
    <f:param name="ngoID" value="#{InsertDataDaoService.ngo_id}" />
</p:commandButton>
```
with
```
@ManagedProperty("#{param.ngoID}")
private Integer ngoID;
```
This way the value will be retrieved (and inlined as part of a JavaScript helper function of the commandButton) during the request of displaying the form, not evaluated during the request of submitting the form.

Sending values with not working working properly in jsf

2 Answers2

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