Example: When @chunk is ignored

The @chunk attribute is ignored in some cases, such as when chunk="combine" is already in effect or when chunk="split" is specified on a grouping element.

Figure 1. Ignoring @chunk when already combining topics

In the following code sample, evaluating chunk="combine" results in one rendered document for each map branch. Any additional @chunk values within those branches are ignored, including any @chunk values within any referenced maps.

<map>
  <title>Ignoring chunking when already combined</title>

  <topicref href="branchOne.dita" chunk="combine">
    <!-- @chunk ignored for branchOneChild.dita -->
    <topicref href="branchOneChild.dita" chunk="split"/>
  </topicref>

  <topicref href="branchTwo.dita" chunk="combine">
    <!-- Any @chunk within submap.ditamap is ignored -->
    <topicref href="submap.ditamap" format="ditamap"/>
  </topicref>
Figure 2. Ignoring @chunk on a grouping element

In the following code sample, chunk="split" is specified on two grouping elements.

<map>
  <title>Trying to "split" groups</title>
  <topicgroup chunk="split">
    <topicref href="ingroup1.dita"><!--...--></topicref>
    <topicref href="ingroup2.dita"><!--...--></topicref>
  </topicgroup>
  <topichead chunk="split">
    <topicmeta>
      <navtitle>Heading for a branch</navtitle>
    </topicmeta>
    <topicref href="inhead1.dita"><!--...--></topicref>
    <topicref href="inhead2.dita"><!--...--></topicref>
  </topichead>
</map>

The result of evaluating chunking is the following:

  • The @chunk attribute on the <topicgroup> element is ignored. The @chunk attribute does not cascade and there is no referenced topic, so it has no effect.
  • In some cases, an implementation might treat the <topichead> element as equivalent to a single title-only topic, while in other cases it might be ignored. In either case, the @chunk value has no effect. If the <topichead> is treated as a title-only topic, it cannot be split further. If it is ignored for the current processing context, it is no different than the <topicgroup> element.