Generate a treemap data structure for visualization with highcharts of files in a MarkLogic database.

treemap-rest.xqy

xquery version "1.0-ml";

module namespace treemap = "http://matthewroyal.com/marklogic/ferret/filetypetreemap";

declare variable $sampleSize := 100;
declare variable $sampleThreshold := 1000;

declare function treemap:get(
  $context as map:map,
  $params  as map:map
) as document-node()*
{
  let $numDocs := xdmp:estimate(cts:search(/, cts:and-query(())))
  let $docTypes := 
    fn:distinct-values(
      if ($numDocs gt $sampleThreshold) then
        (: Just get a sample :)
        for $d in cts:search(/, cts:and-query(()), "score-random" )[1 to $sampleSize]
        return fn:node-name($d/element())
      else
        for $d in cts:search(/, cts:and-query(()))
        return fn:node-name($d/element())
    )
  let $out :=
    "[" || fn:string-join((
      for $p at $i in 
        (: Order by frequency:)
        for $d in $docTypes
        let $dest := xdmp:estimate(cts:search(/, cts:and-query((cts:element-query($d, cts:and-query(()) ))) ))
        order by $dest descending
        return $d||","||$dest
      let $pieces := fn:tokenize($p, ",")
      let $d := $pieces[1]
      let $dest := $pieces[2]
      return "{ name: '" || $d || "', value: " || $dest || ", colorValue: " || $i || " }" 
    ), ",") || "]"

  (: JSON return :)
  let $_ := map:put($context, "output-types", "application/json")
  let $_ := xdmp:set-response-code(200, "OK")
  return document { $out }
};