[seam-dev] Suppressing parameter inclusion for s:link

[Christian Bauer]

On Oct 24, 2008, at 13:21 , Pete Muir wrote:

> As Christian said, <f:param name="whatever" /> is probably the wrong  
> syntax for this, as it implies you are adding a parameter, not  
> removing it. Maybe we need an <s:suppressPageParameter name="foo" />  
> instead.

-1, just document <f:param name="foo" value="#{null}"/> and that's it  
for suppressing a page parameter. Overriding is then consistent with  
<f:param name="foo" value="#{override}"/>. This would be the easiest  
solution. Any syntax we come up with to do the same in a different way  
is going to be more complex.

Or/and we do this:

<page view-id="one.xhtml">
   <param name="foo" value="#{binding.getterAndSetter"/>
   <param name="bar" value="#{binding.getterAndSetter"/>
</page>

Regular link that evaluates #{binding.getterAndSetter} to get the  
"foo" and "bar" parameter values (that's the (current) default):

<s:link view-id="one.xhtml" page-parameters="override"/>

Link that only contains the "bar" parameter with  
#{binding.getterAndSetter} value:

<s:link view-id="one.xhtml" page-parameters="override">
   <f:param name="foo"/>
</s:link:

Link that only contains the "bar" parameter with #{binding.other} value:

<s:link view-id="one.xhtml" page-parameters="override">
   <f:param name="foo"/>
   <f:param name="bar" value="#{binding.other}"/>
</s:link:

Link that only contains the "foo" parameter with  
#{binding.getterAndSetter} value:

<s:link view-id="one.xhtml" page-parameters="ignore">
   <f:param name="foo"/>
</s:link>

Link that only includes the "foo" parameter with #{binding.other} value:

<s:link view-id="one.xhtml" page-parameters="ignore">
   <f:param name="foo" value="#{binding.other}"/>
</s:link>

The advantage here is that we can keep it backwards compatible, if you  
have the default page-parameters="override", the #{null} trick, the ""  
value trick, and the no-value-attribute all continue to work as before.

But really, this is not so much an absolutely necessary code feature,  
it's foremost a documentation change. Even an FAQ entry would be OK.