JSTL conditional check

t0mcat picture t0mcat · Jun 2, 2011 · Viewed 32.1k times · Source

On my current page I am using JSTL to check if data is available for my form. Problem I am facing is "if there is no data I am not seeing the text fields either". I can solve it using and tags but that would entail lot of if else if else kind of code all through the page. Can anyone suggest me a better cleaner solution to this problem?

<c:if test="${salesData!=null}">
  <c:if test="${fn:length(salesBundle.salesArea) > 0}">
  <input type="text" id="sales_area" class="salesManagerStyle">
  </c:if>
</c:if>

Answer

BalusC picture BalusC · Jun 2, 2011

You can have multiple conditions in a test.

<c:if test="${salesData != null && fn:length(salesBundle.salesArea) > 0}">
    <input type="text" id="sales_area" class="salesManagerStyle">
</c:if>

But you can also use the empty keyword to do both a nullcheck and lengthcheck.

<c:if test="${not empty salesData.salesArea}">
    <input type="text" id="sales_area" class="salesManagerStyle">
</c:if>

That's the best what you can get, now. If you need to reuse the same condition elsewhere in the page, then you could also save it by <c:set>.

<c:set var="hasSalesData" value="${not empty salesData.salesArea}" />
...
<c:if test="${hasSalesData}">
    <input type="text" id="sales_area" class="salesManagerStyle">
</c:if>
...
<c:if test="${hasSalesData}">
    Foo
</c:if>