parameter value lost (seam framework)

Question

Hi, After clicking on an image, the user is redirected to a new page like:

/viewPalermoUser.seam?accountId=100245

with the code:

<s:link title="#{messages['palermo.userlist.view']}" view="/portal/custom/palermo/administration/viewPalermoUser.xhtml"
                            propagation="none">
                        <f:param name="accountId" value="#{account.id}"/>
                        <img src="/static/portal/customer/palermo/find.png" style="border:none"/>
                    </s:link>

There is a backing bean where i take the account id and print the account information for that user (when the page is first rendered all it's ok).

BUT have a rich tab panel and a search button. Whenever i press one of this, the accountId value is NULL, although in the url it is the OK, so it has a real value.

I do not understand why the accountId's value is lost if a postback occurs?

I take the accountId like:

@RequestParameter
private Long accountId;

Can anyone give me a clue?

UPDATE: Finally it works. Use page param like Petar suggested. Had problems until i realized that:

A seam page param is not available in @Create method of the backing bean. Workaround: create a page action to use this param. (must be usefull for others)

Thanks.

Answer 1

Hi,

After clicking on an image, the user is redirected to a new page - I suppose it is called /viewPalermoUser.xhtml

First of all, a simple request parameter does not survive a postback.

To solve your problem, you can create a page parameter

<page view-id="/viewPalermoUser.xhtml">
    <param name="courseId" value="#{courseHome.courseId}"/>
</page>

So when Seam notices

<param name="courseId" value="#{courseHome.courseId}"/>

It creates a page parameter and because of value attribute (not required), it is assigned to courseHome.courseId property. Page parameter survives JSF postback.

If you want accountId survive a postback in s:link (or s:button), you have to create a page parameter in the view-id that matchs s:link view="/portal/custom/palermo/administration/viewPalermoUser.xhtml" attribute

So we need

<page view-id="/portal/custom/palermo/administration/viewPalermoUser.xhtml">
    <param name="courseId"/>
</page>

When using page parameter, you do not have to worry about f:param. s:link takes care of it. So your accoutId page parameter is automatically appended to the link.

<s:link title="#{messages['palermo.userlist.view']}" view="/portal/custom/palermo/administration/viewPalermoUser.xhtml"/>

regards,

Answer 2

Hi Cristian,

As far as I know, @RequestParameter works only on an initial request. To solve the problem, you can use a Seam page parameter. Put in your page.xml descriptor the following tag: <param name="accountId" value="#{backingBean.accountId}"/> You don't need the @RequestParameter annotation.