Weird JSTL c:forEach problem

[Wesley Baker]

I am trying to pass a Map key and value to two separate JavaScript arrays:

var labels = [];
var amt = [];
var counter = 0;
<c:forEach items="${actionBean.exclusions}" var="exclusion">
    labels[counter] = ${exclusion.key};
    amt[counter++] = ${exclusion.value};
</c:forEach>

There are no Java errors, and if I use the debugger and step through it the correct values are displayed for each key and value iteration. However, JavaScript seems to be freaking out over the following line:

    labels[counter] = ${exclusion.key};

Because if I add an alert() to display the key, it won't ever pop up. The page finishes loading and nothing ever pops up. The value works fine though.

Am I doing something wrong trying to get the key? I've used the c:forEach before and never had this problem.

Here is the method that is supplying the Map:

    public Map<String,Double> getExclusions() {
        Connection conn = null;
        Statement st = null;
        ResultSet rs = null;
        Map<String,Double> returnVal = new HashMap<String,Double>();
        try {
            conn = PooledDatabaseConnection.getConnection();
            st = conn.createStatement();
            rs = st.executeQuery("SELECT secName, sum(caiAccountBalance)"
                    + " FROM capture_account_info"
                    + " JOIN static_export_codes ON caiXsecID=secID"
                    + " WHERE caiXcfiID=" + getFileId()
                    + " AND caiXsecID <> 1"
                    + " GROUP BY secName");
            
            while (rs.next()) {
                returnVal.put(rs.getString(1), rs.getDouble(2));
            }
        } catch (Exception e) {
            return returnVal;
        } finally {
            try {
                rs.close();
            } catch (Exception e) {}
            try {
                st.close();
            } catch (Exception e) {}
            try {
                conn.close();
            } catch (Exception e) {}
        }
        
        return returnVal;
    }

[Paul Clapham]

Wesley Baker wrote:However, JavaScript seems to be freaking out over the following line:

    labels[counter] = ${exclusion.key};

Is that actually the generated Javascript code? Because the expression ${exclusion.key} should evaluate to something, even if it's an empty string.

[Wesley Baker]

Yes, that's what actually in the code that I'm having problems with. If I do this:

<c:forEach items="${actionBean.exclusions}" var="exclusion">
    alert(${exclusion.value});
</c:forEach>

I get the expected pop up telling me the values. However, if I do this:

<c:forEach items="${actionBean.exclusions}" var="exclusion">
    alert(${exclusion.key});
</c:forEach>

I get nothing. No pop up. It's like the JavaScript is crashing, but I can't figure out if it's because of the String that is being passed to it, or if it's something quirky with JavaScript itself. I even tried:

<c:forEach items="${actionBean.exclusions}" var="exclusion">
    alert(String(${exclusion.key}));
</c:forEach>

But that didn't help.

[Stefan Evans]

I guess the question is, what do you see when you view source on the generated html page?
hint: it should NOT include any EL expressions.

I would expect alert(${exclusion.key}) to fail without quotes around the value being alerted.
ie alert('${exclusion.key}');

so if the value of exclusion.key was "foo" then alert(foo) would fail (undeclared variable) while alert('foo') would succeed.

Is your value a string that include quotes in it? or a number perhaps? alert(42) would work fine :-)

[Paul Clapham]

Wesley Baker wrote:Yes, that's what actually in the code that I'm having problems with.

Could we remove the ambiguity from that statement? Is it in the JSP code, or in the Javascript code which it generates? If you have a Javascript problem then it's the latter you should be looking at, not the former.

(In case you didn't already know, you can see the code in the browser via one of the options when you right-click the page.)

[Wesley Baker]

Stefan Evans wrote:
I would expect alert(${exclusion.key}) to fail without quotes around the value being alerted.
ie alert('${exclusion.key}');

HA! You nailed it, Stefan. That has been bugging me (no pun intended) for hours. I'm so used to Java just "understanding" that when you pass a String, it comes with its own necessary quotes. Adding the single quotes outside the ${exclusion.key} did the trick.

Thanks a bunch!

[Bear Bibeault]

Learn to look at what the browser is seeing. The JSP source is useless to debug client-side issues. A quick look at the actual generated HTML/JavaScript would pinpoint the issue immediately.