[lichtenberger]

That's one of the main steps forward for Brackit, a retargetable JSONiq query engine/compiler (http://brackit.io) and the append-only data store SirixDB (https://sirix.io) and a new web frontend. My vision is not only to explore the most recent revision but also any other older revisions, to display the diffs, to display the results of time travel queries... help is highly welcome as I'm myself a backend engineer and working on the query engine and the data store itself :-)

Detect changes of a specific node and the whole subtree/subtree:

    let $node := jn:doc('mycol.jn','mydoc.jn')=>fieldName[[1]]
    let $result := for $node-in-rev in jn:all-times($node)
                   return
                     if ((not(exists(jn:previous($node-in-rev))))
                          or (sdb:hash($node-in-rev) ne sdb:hash(jn:previous($node-in-rev)))) then
                       $node-in-rev
                     else
                       ()
    return [
      for $jsonItem in $result
      return { "node": $jsonItem, "revision": sdb:revision($jsonItem) }
    ]

Get all diffs between all revisions and serialize the output in an array:

    let $maxRevision := sdb:revision(jn:doc('mycol.jn','mydoc.jn'))
    let $result := for $i in (1 to $maxRevision)
                   return
                     if ($i > 1) then
                       jn:diff('mycol.jn','mydoc.jn',$i - 1, $i)
                     else
                       ()
    return [
      for $diff at $pos in $result
      return {"diffRev" || $pos || "toRev" || $pos + 1: jn:parse($diff)=>diffs}
    ]

Open a specific revision

By datetime:

    jn:open('mycol.jn','mydoc.jn',xs:dateTime('2022-03-01T00:00:00Z'))

By revision number:

    jn:doc('mycol.jn','mydoc.jn',5)

And a view of an outdated frontend:

https://github.com/sirixdb/sirix/raw/master/Screenshot%20fro...