Custom taglib with nested tag not working

Question

Hi everybody,
I have a question concerning a custom taglib. I want to create a tag with nested child tags. The parent tag is some kind of iterator, the child elements shall do something with each iterated object. The parent tag extends BodyTagSupport, i have overriden the methods doInitBody and doAfterBody. doInitBody initializes the iterator and puts the first object in the pageContext to be used by the child tag. doAfterBody gets the next iterator object and puts that in the pageContext, if possible. It returns with BodyTag.EVAL_BODY_AGAIN when another object is available, otherwise BodyTag.SKIP_BODY.
The child tag extends SimpleTagSupport and does something with the given object, if it's there.
In the tld-file I have configured both tags with name, class and body-content (tagdependent for the parent, empty for the child).
The parent tag is being executed as I expected. But unfortunately the nested child tag does not get executed. If I define that one outside of its parent, it works fine (without object, of course).
Can somebody tell me what I might have missed? Do I have to do something special with a nested tag inside a custom tag?
Any help is greatly appreciated!
Thanks a lot in advance!
Greetings,
Peter

Answer 1

Hi again,
unfortunately this didn't work.
I prepared a simple example to show what isn't working. Perhaps it's easier then to show what my problem is:
I have the following two tag classes:
public class TestIterator extends BodyTagSupport {
    private Iterator testIteratorChild;
    @Override
    public void doInitBody() throws JspException {
        super.doInitBody();
        System.out.println("TestIterator: doInitBody");
        List list = Arrays.asList(new String[] { "one", "two", "three" });
        testIteratorChild = list.iterator();
    @Override
    public int doAfterBody() throws JspException {
        int result = BodyTag.SKIP_BODY;
        System.out.println("TestIterator: doAfterBody");
        if (testIteratorChild.hasNext()) {
            pageContext.setAttribute("child", testIteratorChild.next());
            result = BodyTag.EVAL_BODY_AGAIN;
        return result;
public class TestIteratorChild extends SimpleTagSupport {
    @Override
    public void doTag() throws JspException, IOException {
        super.doTag();
        System.out.println(getJspContext().getAttribute("child"));
        System.out.println("TestIteratorChild: doTag");
}The Iterator is the parent tag, the Child shall be shown in each iteration. My taglib.tld looks like the following:
<?xml version="1.0" encoding="UTF-8"?>
<taglib
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee web-jsptaglibrary_2_1.xsd"
     xmlns="http://java.sun.com/xml/ns/javaee"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.1">
     <tlib-version>1.0</tlib-version>
     <short-name>cms-taglib</short-name>
     <uri>http://www.pgoetz.de/taglibs/cms</uri>
     <tag>
          <name>test-iterator</name>
          <tag-class>de.pgoetz.cms.taglib.TestIterator</tag-class>
          <body-content>tagdependent</body-content>
     </tag>
     <tag>
          <name>test-iterator-child</name>
          <tag-class>de.pgoetz.cms.taglib.TestIteratorChild</tag-class>
          <body-content>empty</body-content>
     </tag>
</taglib>And the snippet of my jsp is as follows:
     <!-- TestIterator -->
     <cms:test-iterator>
          <cms:test-iterator-child />
     </cms:test-iterator>The result is that on my console I get the following output:
09:28:01,656 INFO [STDOUT] TestIterator: doInitBody
09:28:01,656 INFO [STDOUT] TestIterator: doAfterBody
09:28:01,656 INFO [STDOUT] TestIterator: doAfterBody
09:28:01,656 INFO [STDOUT] TestIterator: doAfterBody
09:28:01,656 INFO [STDOUT] TestIterator: doAfterBody
So the child is never executed.
It would be a great help if anybody could tell me what's going wrong here.
Thanks and greetings from germany!
Peter
Message was edited by:
Peter_Goetz