IMHO neither loop tag can work here:
foreach is evaluated while building the component tree, so it can't access the item variable at that time.
ui:repeat iterates over a single component, but that won't have any effect, because the f:param is evaluated by the parent component, which will see only a single f:param.

Maybe something like this will work:

<s:link value="#{item.label}" action="#{someHelperBean.gotoTreeNode(item)}/>

where the gotoTreeNode can programmatically setup required parameters in page or conversation context and return an outcome depending on item.viewID.

Or maybe use both view and action attributes on the s:link and let the action simply transfer the parameters.

Tricky...

What really is missing is a JSF tag like

<f:params list="#{paramList}" var="param" name="#{param.name}" value="#{param.value}"/>

Too bad you can't even write such a tag yourself, because the components that are decorated by f:param all contain code like child instanceof UiParameter.
So much for good object oriented design.

Maybe anybody else has a solution?

There's a little workaround we found for this, so i'd like to share.

We (or rather Adam Warski ;-) ) have specified in our taglib two functions

    <function>
        <function-name>makeParamsName</function-name>
        <function-class>com.vocado.frontend.jsf.Parameters</function-class>
        <function-signature>java.lang.String makeParamsName(java.util.SortedMap)</function-signature>
    </function>
    <function>
        <function-name>makeParamsValue</function-name>
        <function-class>com.vocado.frontend.jsf.Parameters</function-class>
        <function-signature>java.lang.String makeParamsValue(java.util.SortedMap)</function-signature>
    </function>

the source class is

package com.vocado.frontend.jsf;

import java.util.Map;
import java.util.SortedMap;
import java.net.URLEncoder;
import java.io.UnsupportedEncodingException;

/**
 * Functions to create a link/button with variable (dynamic) parameters.
 * Usage is quite simple - you just need a SortedMap of your parameters.
 * Then, in the .xhtml, you need to have:
 * {@code <f:param name="{v:makeParamsName(parameterMap)}" value="{v:makeParamsValue(parameterMap)}" />} 
 * @author Adam Warski (adam at warski dot org)
 */
public class Parameters {
     /**
      * Constructs a name for the pseudo-parameter tag, with which you can have dynamic parmeters.
      * Creates a string:
      * key1=value1&key2=value2&key3=value3&...&keyN
      * where all values are url-encoded with UTF-8.
      * The value of the last key will be appended by the value of the parameter.
      * @param map Map, from which to construct the name of the pseudo-parmaeter.
      * @return Name of the pseudo-parameter tag.
      */
     public static String makeParamsName(SortedMap<Object, Object> map) {
          StringBuilder nameSB = new StringBuilder();

          if (map.size() == 0) {
               return null;
          }

          Object lastKey = map.lastKey();
          for (Map.Entry<Object, Object> entry : map.entrySet()) {
               Object key = entry.getKey();
               nameSB.append(key);
               if (!lastKey.equals(key)) {
                    nameSB.append("=");
                    nameSB.append(encode(String.valueOf(entry.getValue())));
                    nameSB.append("&");
               }
          }

          return nameSB.toString();
     }

     /**
      *
      * @param map Map, from which to construct the value of the pseudo-parameter.
      * @return Value of the pseudo-parameter tag: the last value of the map.
      */
     public static String makeParamsValue(SortedMap<Object, Object> map) {
          if (map.size() == 0) {
               return null;
          }

          return String.valueOf(map.get(map.lastKey()));
     }

     private static String encode(String toEncode) {
          try {
               return URLEncoder.encode(toEncode, "UTF-8");
          } catch (UnsupportedEncodingException e) {
               return toEncode;
          }
     }
}

So now, whenever we need to pass multiple parameters without using any iteration inside JSF you have to provide a sorted map with parameters (here just called parameters) and invoke by

 <s:link ...> 
   <f:param name="#{v:makeParamsName(parameters)}" value="#{v:makeParamsValue(parameters)}" />
 </s:link>

Hope it helps,

Tomek
   

Daniel Zwicker wrote on May 26, 2008 12:02:


Hi all,

I have a 'navigation-tree' on my page which is genrerated by a xml file. In the xml I want to provide the posibility to specify url parameters.

So in my xhtml i have code like this:

The s:link with c:forEach is working outside a rich:tree. I have tried ui(a4j):repeat. Can anybody provide me with a hint wat I can do, or what I have missed in the richfaces or seam documentation? Or any hints how I can manage this problem?

By the way the same happens with h:outputLink or h:commandLink

Greetings

That is the wrong approach for rich:tree (but it is the right approach for other richfaces controls) for the rich:tree the right approach is to use a rich:recursiveTreeNodesAdaptor inside the rich:tree. See an example in this page.

Please vote for RF-4128 to make all this more consistent (it asks for the same programming model for all tree/recursive controls).

And remember, this kind of question is for the Richfaces Forum

Mmmm, nevermind, I think I understood your post incorrectly, what you want is a dynamic parameter list for s:link