Can I use Get-Parameter in EL 2.2 without writing it into the Bean?

Question

I want to parse the URL

title.xhtml?id=1

My code within "title.xhtml" should look like

...
<h:outputText value="#{titles.getTitle(${param.id}).id}"></h:outputText>
...

But unfortunatelly this does not work, since nested "#" and "$" is not accepted. So my question is: Can I use an URL parameter and hand it over to a bean function without to store it separately within the bean?

Just curious, what are you avoiding by not having a bean-property? — Aksel Willgert, Dec 29 '12 at 19:24
I would have thought that `#{titles.getTitle(param.id).id}` would do it. — McDowell, Dec 29 '12 at 19:30
@ Aksel Willgert: the answer #{titles.getTitle(param.id).id} seems to be more readable; 1 line code instead of about 6. — Alex004, Dec 30 '12 at 09:48

score 1 · Accepted Answer · edited May 23 '17 at 10:24

That's invalid EL syntax. You can't and don't need to nest EL expressions in any way. Even nesting ${} is invalid. The only difference between #{} and ${} is that the #{} can perform a set operation as well (where applicable), while the ${} can do only a get operation.

This is valid EL syntax:

<h:outputText value="#{titles.getTitle(param.id).id}" />

Note that #{param.id} is fully legal JSF EL syntax. To avoid future confusions, it would be a good idea to make sure that you never use the old JSP EL syntax ${} in JSF anymore. See also Difference between JSP EL, JSF EL and Unified EL.

Can I use Get-Parameter in EL 2.2 without writing it into the Bean?

1 Answers1