Concatenating strings within EL expression defined in an attribute of a facelets tag

Rajat Gupta picture Rajat Gupta · Sep 12, 2011 · Viewed 84k times · Source

I need to write an EL expression for an attribute which goes something like this:

#{cc.attrs.appreciatedByCurrentUser ? (cc.attrs.count +'<br/>'+ (cc.attrs.count-1)) : ((cc.attrs.count+1) +'<br/>'+ cc.attrs.count)}

Now the problem is that this gives an error as strings cannot be concatenated, the way I am doing it. So how can I rectify this?

I'm using JSF 2.0 with facelets.


EDIT :

I'm resolving the issue using the following inline javascript

            <script type="text/javascript">
                var count=#{cc.attrs.count};
                document.write(#{cc.attrs.appreciatedByCurrentUser} ? (count-1) +'<br/>'+count  : count+'<br/>'+ (count+1));
            </script>

Can you think of any issue with this?

Answer

SlavaSt picture SlavaSt · Nov 10, 2012

It is possible to concatenate Strings in EL using the java.lang.String.concat(String) method. Thus your code could look like:

<h:outputText value="#{cc.attrs.appreciatedByCurrentUser ?  (''.concat(cc.attrs.count).concat('&lt;br/&gt;').concat(cc.attrs.count-1)) :  (''.concat((cc.attrs.count+1)).concat('&lt;br/&gt;').concat(cc.attrs.count))}" escape="false" />

In this particular case however I would go with one of the options that Mr BalusC had suggested because the code above doesn't look quite elegant. In some cases knowing this technique could be useful, though.

I would hardly recommend using javascript as a workaround here.