Hi!

Why not use my DynamicEl Component for Seam Expressions? I think you can port it quite easily to other ELs. It's not optimal yet, but it's a start. It'd need to be enhanced to support more than one Expression on a page.

public class DynamicExpressionLanguage
{
 private String dynamicEL;

 public Expressions.ValueExpression<Object> getValueExpression()
 {
 Expressions expressions = Expressions.instance();

 String eval = "#{" + dynamicEL + "}";

 if (dynamicEL == null)
 {
 eval = "#{'itsnull'}";
 }

 Expressions.ValueExpression<Object> el = expressions.createValueExpression(eval);
 return el;
 }

 public void setCurrentValue(Object value)
 {
 Expressions.ValueExpression<Object> el = getValueExpression();
 el.setValue(value);
 }

 public Object getCurrentValue()
 {
 return getValueExpression().getValue();
 }

 public void invoke(Object... objects)
 {
 Expressions expressions = Expressions.instance();

 String eval = "#{" + dynamicEL + "}";

 if (dynamicEL == null)
 {
 eval = "#{'itsnull'}";
 }

 try
 {
 Expressions.MethodExpression<Object> el = expressions.createMethodExpression(eval);
 el.invoke(objects);
 }
 catch (Exception ex)
 {
 FacesContext.getCurrentInstance().addMessage("messages", new FacesMessage("Could not call desired action: " + eval));
 }
 }

 public void setDynamicEL(String dynString)
 {
 this.dynamicEL = dynString;
 }

 public String getDynamicEL()
 {
 return this.dynamicEL;
 }

}

<h:form>
<h:inputText value="#{comp.dynel}" />
<h:outputText value="#{comp.dynel.currentValue}" />
<h:commandButton value="show" />
</h:form>

fixt

<h:form>
<h:inputText value="#{comp.dynel.dynamicEL}" />
<h:outputText value="#{comp.dynel.currentValue}" />
<h:commandButton value="show" />
</h:form>