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jstl c:if condition is not working

Posted on 2015-02-06
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Last Modified: 2015-02-06
How program should work :
1) Once the user selects the file from first select box, second select box gets populated.
2) After selecting one option from second select box "hi there" must be displayed.

How the program is working
From above mentioned steps, once the user selects file from first select box the second select box is getting populated and at the same time before selecting any option from second select box "hi there" is displayed.
i want to display "hi there" after selecting an option from second select box.

I think it has something to do with : <c:if test='<%=cubeValue != "select" %>'> line of code.

<jsp:useBean id="c1" class="mypkg.Cubes"></jsp:useBean>

<div id="file">
<form name="s_file" method="post" action="">
<select id="selected_file" name="selected_file" onchange="s_file.submit();">
<option value="Select">Select schema</option>
<c-rt:forEach var="file" items="<%=fileNames%>">
 <option value="<c:out value="${file}"/>"><c:out value="${file}"/></option>
</c-rt:forEach>
</select>

<c:if test='${pageContext.request.method=="POST"}'>
<c:if test='${request.getParameter("selected_file") ne "Select"}' >

<c:set value="<%=fileValue %>" target="${c1}" property="schemaFile"/>
<c:out value="${c1.Connect()}"></c:out>


 <select id="selected_cube" name="selected_cube" onchange="s_file.submit()">
<option value="select">Select Cube</option>

<c:forEach var="i" begin="0" end="<%=c1.getCubes().size()-1%>" step="1">
 <option value='<c:out value="${i}"/>'><c:out value="${ c1.getCubes().get(i).getName()}"/></option>
 </c:forEach>
</select>

<c:if test='<%=cubeValue != "select" %>'>

<c:out value="hi there"/>
</c:if>
</c:if>

</c:if>

</form>

</div>

</body>

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Please help
thanks
0
Comment
Question by:Pradip Shenolkar
  • 2
  • 2
4 Comments
 
LVL 27

Expert Comment

by:rrz
ID: 40594770
<c:if test='<%=cubeValue != "select" %>'>
That won't work.  What is cubeValue? If it is a scoped variable, then you could try
<c:if test='${cubeValue != "select"}'>

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<c:if test='${request.getParameter("selected_file") ne "Select"}' >
That won't work. You could try using.
<c:if test='${param.selected_file  ne "Select"}' >

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0
 

Author Comment

by:Pradip Shenolkar
ID: 40595081
I tried your solution but its not working

Here is full code which makes it clear what cubeValue is.(see in scriptlet)

<%
   String fileValue = request.getParameter("selected_file");
   if(fileValue == null)fileValue = "Select File";
   
   String cubeValue = request.getParameter("selected_cube");
   if(cubeValue == null)cubeValue = "Select Cube";

%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>

<script type="text/javascript">

function retainValue(){
     var element1 = document.forms[0].selected_file;
     for(x = 0; x < element1.length; x++){
             if(element1.options[x].value == "<%=fileValue%>"){
                   element1.options[x].selected = true;
                   break;
             } 
     }
     
     var element2 = document.forms[0].selected_cube;
     for(x = 0; x < element2.length; x++){
             if(element2.options[x].value == "<%=cubeValue%>"){
                   element2.options[x].selected = true;
                   break;
             } 
     }
}
</script>
</head>
<body onload="retainValue();">
<%
String folder=application.getRealPath("/WEB-INF/schemas");
File file=new File(folder);
String fileNames[]=file.list();

%>


<jsp:useBean id="c1" class="mypkg.Cubes"></jsp:useBean>

<div id="file">
<form name="s_file" method="post" action="">
<select id="selected_file" name="selected_file" onchange="s_file.submit();">
<option value="Select">Select schema</option>
<c-rt:forEach var="file" items="<%=fileNames%>">
 <option value="<c:out value="${file}"/>"><c:out value="${file}"/></option>
</c-rt:forEach>
</select>

<c:if test='${pageContext.request.method=="POST"}'>
<c:if test='${request.getParameter("selected_file") ne "Select"}' >

<c:set value="<%=fileValue %>" target="${c1}" property="schemaFile"/>
<c:out value="${c1.Connect()}"></c:out>


 <select id="selected_cube" name="selected_cube" onchange="s_file.submit()">
<option value="select">Select Cube</option>

<c:forEach var="i" begin="0" end="<%=c1.getCubes().size()-1%>" step="1">
 <option value='<c:out value="${i}"/>'><c:out value="${ c1.getCubes().get(i).getName()}"/></option>
 </c:forEach>
</select>

<c:if test='${param.selected_cube ne "select" }'>

<c:out value="hi there"/>
</c:if>
</c:if>

</c:if>

</form>

</div>

</body>
</html>

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0
 
LVL 27

Accepted Solution

by:
rrz earned 500 total points
ID: 40595154
I stripped out the bean code and put dummy data into your code. I also added page scoped variables that can be  accessed by EL in the JSTL. Does this code do what you want it to do?
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> 
<%
   String fileValue = request.getParameter("selected_file");
   if(fileValue == null)fileValue = "Select File";
   pageContext.setAttribute("fileValue", fileValue);
   String cubeValue = request.getParameter("selected_cube");
   if(cubeValue == null)cubeValue = "Select Cube";
   pageContext.setAttribute("cubeValue", cubeValue);
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
<script type="text/javascript">

function retainValue(){
     var element1 = document.forms[0].selected_file;
     for(x = 0; x < element1.length; x++){
             if(element1.options[x].value == "<%=fileValue%>"){
                   element1.options[x].selected = true;
                   break;
             } 
     }
     
     var element2 = document.forms[0].selected_cube;
     for(x = 0; x < element2.length; x++){
             if(element2.options[x].value == "<%=cubeValue%>"){
                   element2.options[x].selected = true;
                   break;
             } 
     }
}
</script>

</head>
<body onload="retainValue();">
    <div id="file">
    <form name="s_file" method="post" action="">
        <select id="selected_file" name="selected_file" onchange="s_file.submit();">
            <option value="Select File">Select schema</option>
            <c:forEach var="file" items="a,b,c,d">
                <option value="<c:out value="${file}"/>"><c:out value="${file}"/></option>
            </c:forEach>
        </select>
    <c:if test='${fileValue ne "Select File"}' >
        <select id="selected_cube" name="selected_cube" onchange="s_file.submit()">
            <option value="Select Cube">Select Cube</option>
            <c:forEach var="i" begin="0" end="3" step="1">
                <option value='<c:out value="${i}"/>'><c:out value="${i}"/></option>
            </c:forEach>
        </select>
    <c:if test='${cubeValue ne "Select Cube" }'>
        <c:out value="hi there"/>
    </c:if>
    </c:if>
    </form>
    </div>
</body>
</html>

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Are you using an old book? I haven't seen <c-rt: used in a very long time.
0
 

Author Closing Comment

by:Pradip Shenolkar
ID: 40595188
It works like charm.

Thank you so much for helping.
0

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