Need help with JSTL: setting end attribute dynamically of "substring" tag

[Maan Suraj]

I have a scenario wherein i need to capitalize the first letter of a word. From Action class, i get everything in lowercase.

  <c:set var="excfirstletterofname">
						<c:set var="secondNameLength">
							  		<str:length><c:out value="${abc.name}" />							  
							  		</str:length>	
						</c:set>
							  					
						<c:set var="firstletterofname">
							  		<str:substring start="0" end="1"><str:upperCase><c:out value="${abc.name}"/></str:upperCase></str:substring>
					        </c:set>
							  
						
				<str:substring start="1" end="5"><c:out value="${hotelViewHelper.destinationName}"/></str:substring>
</c:set>		

Above code works fine. ${abc.name}, say gives us value "india". Now i want to convert and display in my front end as "India".
Initially, iam getting the length of ${abc.name}, in this case for india length will be 5.This length is stored in a variable called "secondNameLength". As mentioned earlier the above code works fine
However, if I change the last line i.e

<str:substring start="1" end="5"><c:out value="${hotelViewHelper.destinationName}"/></str:substring>

to


<str:substring start="1" end="${secondNameLength}"><c:out value="${hotelViewHelper.destinationName}"/></str:substring>

then it doesnot work as expected. I printed this value separately${secondNameLength}, and it works fine. however within the "end" attribute it doesnot work as expected.

[Frits Walraven]

Maan Suraj,

I am not sure why your code is not working well, but what you can try is rewriting it with EL functions:
refer to the following taglib uri

 <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>   

And add the following in your jsp:

  
<c:set var="secondNameLength">   
    ${fn:length(e)}
</c:set>

<c:set var="firstletterofname" scope="page">   
     ${fn:substring(e, 0, 1)} 
</c:set>

${fn:toUpperCase(firstletterofname)}
${fn:substring(e, 1, secondNameLength)}
  

In my case the String identified with e had a value of "errors" and the output was: E rrors

Regards,
Frits

[Maan Suraj]

Thanks,
but I cannot use "http://java.sun.com/jsp/jstl/functions" as our project uses struts1.0. So i cannot use the above approach. I need something which is possible with help of struts-tiles.tld.

Please help

[Frits Walraven]

I am not familiar with struts 1.1 (we are using struts 1.2.15) and also not with the tld file you are using. Please verify if the "end" attribute has an allowance <rtexprvalue>true</rtexprvalue>

What I don't understand is why you can't import a standard taglib (like jstl) in your page?

Regards,
Frits

[Maan Suraj]

when i try importing twhat you said i.e "..jstl/functions", gives an exception which says

ServletException in:/jsp/ah/abc.jsp] The absolute uri: http://java.sun.com/jsp/jstl/functions cannot be resolved in either web.xml or the jar files deployed with this application'

Please let me know if there is any alternative...

[Frits Walraven]

Have you verified that the "end" attribute in the tld-file that you use has an allowance <rtexprvalue>true</rtexprvalue> ?
Maybe the " end" attribute is not allowed to have a realtime expression value like you are using ${secondNameLength}.

Or you can download the standard jstl and put it in your application:
JSTL

Regards,
Frits

[Frits Walraven]

If you download for instance 1.1.2 you will find the jstl.jar and the standard.jar (in the lib directory).

put them in the /WEB-INF/lib directory and the container will now find the absolute url that I gave you (because the tld file contains that url and is inside the .jar file)

[Maan Suraj]

I verified "end" attribute in the tld-file is something like <rtexprvalue>true</rtexprvalue> . So i dont know what the issue is .Now as you mentioned i downloaded the JSTL and standard.jar


Now , i would like to know what exactly do i need to keep in place of "e" mentioned in your code

${fn:length(e)}

I tried the below two and tried printing but of no use

<c:set var="secondNameLength">     
     ${fn:length("${abc.name}")}  
 </c:set>  
<c:out value="${secondNameLength}"/>

printed nothing but the code itself

Also below didnot helped either

<c:set var="secondNameLength">     
     ${fn:length(${abc.name})}  
 </c:set>  
<c:out value="${secondNameLength}"/>

Above didnot helped either

So please tell me how can i retrieve the values etc

[Frits Walraven]

it should be like this:

  
<c:set var="secondNameLength">       
     ${fn:length(abc.name)}    
 </c:set> 

  

[Maan Suraj]

 <c:set var="secondNameLength" scope="page">     
   								  ${fn:length(abc.name)} 				  
   								  								    
 </c:set>  
 						
 							<c:out value="${secondNameLength}"/>

Above code, due to some reason is not working properly. When i try to print "secondNameLength" using <c:out value="${secondNameLength}"/>, prints the same i.e i see

${fn:length(abc.name)}

in my output jsp page.

If i do <c:out value="${abc.name}"/>, then it prints "india", as expected.So "abc.name" is available in jsp, however, fn:length...etc method is not able to retrieve it somehow.


Now any idea why this happens?

[Frits Walraven]

ok, this looks like EL is switched off, probably you are using Servlet 2.3 or earlier or EL is switched off for your application via the web.xml (check web.xml for <el-ignored>).
If you are using Servlet 2.3 or earlier (then EL is switched off by default) switch it on via the page directive

  <%@ page isELIgnored='false' %>  

then try the following (without the c:set around it !)

 ${fn:length(abc.name)}    

this should now give output.....

[Maan Suraj]

This do helps Frits . But how do I Use <c:set> and other tags like <c:choose> tags now

<%@ page contentType="text/html;charset=UTF-8" language="java" %>


<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored='false' %>  
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
${fn:length(abc.name)} aaaaaaa

Above code works fine.

However, if I include <c:choose>,<c:set> tags etc, i get an error which says

According to TLD or attribute directive in tag file, attribute value does not accept any expressions'

.

Now what is to be done? The modifications needs to be done in the existing jsp, so i need to keep all these tags like <c:set>, <c:choose> tags etc.

Just wanted to say thanks for your patience and quick and helpful responses.

[Frits Walraven]

oke, now we are almost there.
The only problem that we are having now is that it is taking an old definition of the <c:set> where there is no rtexprvalue allowed. That old definition is mainly there for backwards compatablility. The standard.jar actually has 3 tld files with different definitions of the <c:set> and all the other tags (c.tld, c-1.0.tld and c1-0_rt.tld).

If you include the following page directive:

  <%@ taglib prefix="c_rt" uri="http://java.sun.com/jstl/core_rt"; %>  

it will work for the c:set, but maybe not for the rest.

If not, download the jstl1.2 jar
JSTL 1.2

let us see if that works...

[Frits Walraven]

I have looked at it again and I think you are using the jstl1.0 where the <c:set> attribute value doesn't allow any rtexprvalue. From jstl1.1 onwards it allows real time expressions. Did you download jstl1.0 ?

Before we started with your question everything was working well (with c:set en c:choose). It seems we are now overruling your tld-file with an older one. Where does your taglib directive in your jsp point to? Did you change that?

[Maan Suraj]

From jstl1.1 onwards it allows real time expressions. Did you download jstl1.0 ?

I have downloaded JSTL1.1 only, so the issue is not here it seems.

Before we started with your question everything was working well (with c:set en c:choose)

<c:set> and <c:choose> worked well. The problem was that i was unable to set the value of "end" attribute dynamically.

Where does your taglib directive in your jsp point to? Did you change that?

Initially i had
abc.jsp

<%@ include file="/jsp/applications/common/TaglibsCommon.jsp" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<c:set var="metaTags"><c:out value="${abc.name}" escapeXml="false"/></c:set>
<c:out value="${abc.name}" escapeXml="false"/>

And few more <c:set> tags etc.
TaglibsCommon.jsp contains references to various struts taglibs. Please find below the code

<%-- Struts Taglibs --%>
<%@ taglib uri="/WEB-INF/tld/struts-bean.tld"     prefix="bean"   %>
<%@ taglib uri="/WEB-INF/tld/struts-html.tld"     prefix="html"   %>
<%@ taglib uri="/WEB-INF/tld/struts-tiles.tld"    prefix="tiles"  %>
<%@ taglib uri="/WEB-INF/tld/struts-string.tld"   prefix="str" %>
<%-- JSTL Taglibs --%>
<%@ taglib uri="/WEB-INF/tld/c.tld"   prefix="c" %>
<%@ taglib uri="/WEB-INF/tld/fmt.tld" prefix="fmt" %>

After this i downloaded jstl1.1 & standard.jar 1.1 , and placed them in lib directory.

Now , my abc.jsp (please compare with above one) looks something like below (as per our discussions)

<%@ include file="/jsp/applications/common/TaglibsCommon.jsp" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored='false' %>  
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
value is ${fn:length(abc.name)} 

Above gives me output "value is 6" .Which is perfectly ok.

Now i change my abc.jsp a little bit and it becomes interesting

<%@ include file="/jsp/applications/common/TaglibsCommon.jsp" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page isELIgnored='false' %>  
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>

<c:set var="abcName" scope="page">
${fn:length(abc.name)}
</c:set>
 val<c:out value="${abcName}"/>

and now i get the error According to TLD or attribute directive in tag file, attribute value does not accept any expressions' .

[Frits Walraven]

it is not clear to me yet why it is not working, but let's try this:

Don't include TaglibsCommon.jsp, but include the following taglibs in your abc.jsp:

    
<%@ taglib uri="/WEB-INF/tld/struts-bean.tld"     prefix="bean"   %>  
<%@ taglib uri="/WEB-INF/tld/struts-html.tld"     prefix="html"   %>  
<%@ taglib uri="/WEB-INF/tld/struts-tiles.tld"    prefix="tiles"  %>  
<%@ taglib uri="/WEB-INF/tld/struts-string.tld"   prefix="str" %>  

<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %> 
<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jstl/fmt" %>

This way we are sure that you are using the jstl1.1.
Have you got any taglib reference in your web.xml?

[Frits Walraven]

Sorry change these (jstl1.0)

    
<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %>  
<%@ taglib prefix="fmt" uri="http://java.sun.com/jstl/fmt" %> 

into (jstl1.1)

    
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>