How to concatenate two Boolean values with OGNL in Struts 2?

Question

I have two variables set like this:

<s:set var="A" value="true" />
<s:set var="B" value="false" />

I want to generate the HTML below with a custom attribute info like this :

<td info="truefalse">&#160;</td>

I tried the following lines in my JSP file but I can't get true next to false:

<td info="<s:property value="#A?'true':'false'+#B?'true':'false'""/>&#160;</td>

outputs: <td info="true"> </td>

<td info="<s:property value="#A" /><s:property value="#B" />">&#160;</td>

outputs: <td info="false"> </td>

The first one won't work because you have syntax errors. The second one should work. — Aleksandr M, Jun 05 '14 at 09:49
@AleksandrM I have updated my question with the outputs of the solution I tried — Stephan, Jun 05 '14 at 09:57
The first one won't generate that kind of output, because it throws an exception. — Aleksandr M, Jun 05 '14 at 10:00
Yeah, I guess the missing `/>` is in the posted code only. BTW Stephan, why are you messing with this kind of things ? Which is the larger picture, what are you trying to achieve ? — Andrea Ligios, Jun 05 '14 at 10:04
Looking at the answers IMO this is better suited in code golf site. :D — Aleksandr M, Jun 05 '14 at 10:23

score 2 · Accepted Answer · answered Jun 05 '14 at 10:39

2

OGNL uses + to concatenate strings. Having boolean values to convert to string, you should do something like

<s:property value="%{''+#A+#B}"/>

answered Jun 05 '14 at 10:39

Roman C

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Is it possible to view the `trace evaluation` of ognl used by Struts ? – Stephan Jun 06 '14 at 02:11
It would be good if you ask this in another question with explanation why do you need it. – Roman C Jun 06 '14 at 06:39
Please find my question related to `trace evaluations` here: http://stackoverflow.com/q/24078472/363573 – Stephan Jun 06 '14 at 09:30

prem30488 · Answer 2 · 2014-06-05T10:26:49.363

Use <s:if> Try this

<s:set var="A" value="true" />
<s:set var="B" value="false" />

<td info="<s:if test="%{#A==true}">true</s:if><s:else>false</s:else><s:if test="%{#B==true}">true</s:if><s:else>false</s:else>">&#160;</td>
 OR
<td info="<s:property value="#A" /><s:property value="#B" />">&#160;</td>

outputs:

<td info="truefalse">&#160;</td>

Reason: You can not concatenate Boolean. You need to convert Boolean to string and you can concatenate strings only.

score 0 · Answer 3 · answered Jun 05 '14 at 09:51

0

Try this this might help you..

<td info="<s:property value="A"></s:property><s:property value="B"></s:property>"> </td>

answered Jun 05 '14 at 09:51

user3709610

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2

I tried and I get this output: ` ` – Stephan Jun 05 '14 at 09:57
This link can be useful for you http://mail-archives.apache.org/mod_mbox/struts-user/200711.mbox/%3C4740E6CF.604@pussep.de%3E – user3709610 Jun 05 '14 at 10:08

How to concatenate two Boolean values with OGNL in Struts 2?

3 Answers3