How to link to page using level of indirection

[henrik.lindberg]

Hi, I currently have this:

<h:outputLink value="object-view.seam">
 <f:param name="oid" value="#{x.id}"/>
 <h:outputText value="#{x.name}" />
 </h:outputLink>

to go to a detailed view of the object when clicked on the link.
I want to be able to call a method to determine which view to go to depending on the Class of x.

Essentially what I would want to do is write:

<h:outputLink value="#{myViewSelector.selectViewFor(x)}">
 <f:param name="oid" value="#{x.id}"/>
 <h:outputText value="#{x.name}" />
 </h:outputLink>

I have written a ViewSelector class with a method that takes an instance of x and determines which view I want, I then return "object-view.seam" or something similar.

This does not work, so I wonder how I am supposed to do this.
Any suggestions that helps a newbie like me are much appreciated.

[awheeler]

You could use <s:link> with action parameter. The action event should return a view-id (JSF or otherwise). Using the SeamFaceletViewHandler you should be able to pass parameters to the action event e.g #{myBean.objectSelected(x)}

[henrik.lindberg]

Thanks, after some tweaking (and forgetting to have a "/" first in the view-id :-( ) I got it working. This is what I ended up with:

<s:link
 action="#{viewSelector.viewForObject(x)}"
 value="#{x.name}">
 <f:param name="oid" value="#{x.id}"/>
</s:link>

I think this could be clarified in the documentation under the s:link, s:button section - i.e. add:
"If you want the action to result in a redirect to a view, please remember to include a leading '/', otherwise the returned string is interpreted as an 'outcome' (that can be redirected using declarations in pages.xml)."

It would also be very helpful if the s:link section included that it is possible to use f:param to pass on parameters.

Regards

[henrik.lindberg]

Well - actually - I was not paying attention - it did not work - as I did not get the oid parameter in the URL.

How should that be done when using s:link ?

[henrik.lindberg]

The f:param was passed as a parameter in the URL that leads to the viewSelector - so the question is how to get a page parameter into the result from the action ???

[henrik.lindberg]

I really need help - I am stuck on this.

Basically I want to do:

<a href="#{viewSelector.viewForObject(x)}?oid=#{x.oid}">some text</a>

But I have failed to figure out how to create such an URL.
If I use s:link I can call the method viewForObject and pass a paramter and get the view back, but then the parameter is lost (it is applied to the invocation of the action).

I then thought about using multiplen h:outputLink with static declaration of the various viewids and using

rendered="#{viewSelector.viewForObject(x) == 'view-x'}"

but that is not valid (or? can this be made to work?)

I then looked at doing this with a page navigation rule instead, but my head starts to spin - how do this with page rules?
Should I have a fictious page-id that I navigate to with
redirects depending on the outcome of my method? Or add a page that never gets rendered, only redirected from? But how do I get the value of x.id in there?

Any help much appreciated...
Regards
"confused newbie"

[awheeler]

Your selection action passes the object x. You may be able to return a string of the view such as "/myobjectview.seam?id=" + x.id. I haven't tried this.

Better still you could use the navigation rules in pages.xml as per the seam documentation (section 5.1.1.2):

<page view-id="/viewSelector.xhtml">

 <navigation from-action="#{viewSelector.viewForUpdate}">
 <rule if="objectViewOne">
 <end-conversation/>
 <redirect view-id="/objectViewOne.xhtml">
 <param name="id" value="#{viewSelector.x}"/>
 </redirect>
 </rule>
 </navigation>

</page>

[henrik.lindberg]

Thanks awheeler - I tried the first but did not succeed.

And thanks for the page navigation-rule example. I got confused thinking that I needed to have from-action include parameter - but your example makes it clear, I just have to keep x from the call to virewForUpdate in the ViewSelector instance so I can pick it up again as a parameter. Understand how to make that work.

What I don't like about this solution is that it ads yet another place to configure the mapping.

What I ended up doing was this:

<h:outputLink value="#{x.type}-view.seam" >
 <f:param name="oid" value="#{x.id}" />
 #{x.name}
</h:outputLink>

Which naturally is far less elegant as it ties the view to the type (which I already had).
Will explore the page navigation rule approach sometimes later.

I would have loved to have this possibility directly available in s:link (i.e. ability to call method with parameter to set the value).

Regards