evaluate EL inside EL

[Jelo Nehuptra]

I want to render something like this:

File 'asdf.txt' has an invalid file format.
but my code

${param.err eq 3 ? '<p class="error">File \'<b>${param.fileName}</b>\' has an invalid file format.</p>' : ''}

renders it as:
File '${param.fileName}' has an invalid file format.

Does anyone know how can I get the container to evaluate the ${param.fileName} using EL but not the core if tags?

[Bear Bibeault]

You should not be using the ternary operator for this, but using the <c:if> tag. Why not use what's clearest and most appropriate? Embedding HTML inside strings is a poor practice, and ternary operator is intended as a simple expression switch, not as a replacement for a conditional statement.

And, no you cannot embed an EL expression inside another. The ${} delimiters enclose the entire EL expression and there is no need nor allowance for nesting them.

<c:if test="${param.err == 3}">
  <p class="error">File '<b>${param.fileName}</b>' has an invalid file format.</p>
</c:if>

[Stefan Evans]

As another suggestion seeing as we're using JSTL.
Pull the static string out into a resource bundle:

<c:if test="${param.err == 3}">  
   <p class="error"><fmt:message key='error.invalidFileFormat'>
      <fmt:param value="${param.fileName}:/>
    </fmt:message></p>  
</c:if>  

[Bear Bibeault]

Always a good suggestion!