How do I search for all child topics, including their descendants?

1 Using TreePlugin

%TREE{web="System" topic="AdminDocumentationCategory"}%

• There are several options for formatting, however, it doesn't seem to support delayed macros which is a necessary formatting feature required for some advanced usage.
• Only TOPICPARENT.name relationship is traversed.
• A cache of the topic heirarchy is maintained in working, so performance is reasonable.

2 Using DBCachePlugin's DBRECURSE

%DBRECURSE{"System.AdminDocumentationCategory"}%

• Advanced formatting options, including all those supported by DBQUERY.
• Advanced querying options using the filter param, allowing you to traverse relationships other than TOPICPARENT.name. See DBCacheContrib to read about the DBCache meta-map.
• A cache of all topic data is maintained as a normal part of DBCacheContrib feature, so performance is reasonable

You must consider using FastCGIEngineContrib or ModPerlEngineContrib in order to maintain site performance using DBCachePlugin & DBCacheContrib - although a site can be faster using these plugins, a Foswiki running "plain old CGI" will be slower unless mod_perl or mod_fcgid is used

3 Using nested includes

<verbatim class="tml">%STARTSECTION{"recurse"}%%INCLUDE{
  "%TOPIC%"
  section="recursestep"
  web="%IF{"NOT (defined web AND $'web')" then="%INCLUDINGWEB%" else="%web%"}%"
  topic="%topic%"
  query="%IF{"NOT (defined query AND $'query')" then="parent.name='$percnttopic$percnt' AND parent.name!=name" else="%query%"}%"
  indent="%IF{"NOT (defined indent AND $'indent')" then="" else="%indent%"}%"
  recurse="%IF{"NOT (defined recurse AND $'recurse')" then="off" else="%recurse%"}%"
  header="%IF{"NOT (defined header AND $'header')" then="" else="%header%"}%"
  format="%IF{"NOT (defined format AND $'format')" then="$percntindent$percnt   * [[$web.$topic][$topic]]" else="%format%"}%"
  separator="%IF{"NOT (defined separator AND $'separator')" then="$dollarn" else="%separator%"}%"
  footer="%IF{"NOT (defined footer AND $'footer')" then="*Total:* $dollarntopics" else="%footer%"}%"
  pager="%IF{"NOT (defined pager AND $'pager')" then="on" else="%pager%"}%"
  pagesize="%IF{"NOT (defined pagesize AND $'pagesize')" then="10" else="%pagesize%"}%"
  pagerformat="%IF{"NOT (defined pagerformat AND $'pagerformat')" then="Page $currentpage of $numberofpages [[$nexturl][next page]]" else="%pagerformat%"}%"
}%%ENDSECTION{"recurse"}%%STARTSECTION{"recursestep"}%%SEARCH{
  "%query%"
  nonoise="on"
  type="query"
  web="%web%"
  recurse="%recurse%"
  header="%header%"
  limit="10"
  format="%format%%separator%$percntINCLUDE{ 
    limit=\"5\"
    \"%WEB%.%TOPIC%\"
    section=\"recursestep\"
    web=\"$web\"
    topic=\"$topic\"
    indent=\"%indent%   \"
}$percnt"
  separator=""
  nofinalnewline="on"
  footer="%footer%"
  pager="%pager%"
  pagesize="%pagesize%"
  pagerformat="%pagerformat%"
}%%ENDSECTION{"recursestep"}%</verbatim>

*Example:*
<verbatim class="tml">%INCLUDE{"%TOPIC%" section="recurse" web="System" topic="AdminDocumentationCategory"}%</verbatim>

*Result:*
<pre class="tml">%INCLUDE{"%TOPIC%" section="recurse" web="%SYSTEMWEB%" topic="AdminDocumentationCategory"}%</pre>

Notes:

<blockquote>%X% This is a *very* slow alternative to Extensions.TreePlugin & Extensions.DBCachePlugin (unless you're using Extensions.DBIStoreContrib or Extensions.MongoDBPlugin)</blockquote>

   * TODO: Show a parameterised set statement (trunk/Foswiki 2.0 only)
   * TODO: =separator= param not quite doing what it should
   * Allows equivalent queries & formatting as Extensions.DBCachePlugin