Query model doesn't work properly with a multilevel document list

[Nekhelesh Ramananthan]

While using a Query model in a listview, I have noticed a weird scenario where it happens to kick out some index fields. Here is the code I used. Starting of with the document, index and query definitions,

U1db.Document {
        database: appDb
        docId: 'eyeOfTheTiger'
        create: true
        defaults: { "playlist": { "name": "oldies", "tracks": [ { "file": "old1", "title": "very old song" },{ "file": "old2", "title": "even older" } ] } }
   }

U1db.Index{
        database: appDb
        id: by_playlist
        expression: ["playlist.name", "playlist.tracks.file", "playlist.tracks.title"]
    }

    U1db.Query{
        id: aQuery
        index: by_playlist
        query: [{"name":"*"}, {"file":"*"}, {"title":"*"}]
    }

Here below is the listview where this query model is used.

ListView {
            id: playlistView

            model: aQuery
            clip: true
            spacing: units.gu(2)
            anchors {
                left: parent.left
                top: parent.top
                right: parent.right
                bottom: addButton.top
                margins: units.gu(2)
            }

            delegate: Item {
                width: parent.width
                height: childrenRect.height

                Column {
                    Text { text: contents.name }
                    Text { text: contents.file + "|" + contents.title }
                }
            }
 }

On running the program, I get the output referring to contents.name as undefined.
Unable to assign [undefined] to QString

Here is the strange part, If I change the index expression to ["playlist.name", "playlist.tracks"], then contents.name seems to be properly displayed. However now we lose the playlist.tracks field. This only happens when there are multiple layer lists in a document. If they are on the same level, it seems to work fine.

[Nekhelesh Ramananthan (nik90)]

Here is a sample test program which indicates the issue.

[Joshua Gleitze (joshua-gleitze)]

I think this may be related to https://bugs.launchpad.net/u1db-qt/+bug/1215898 or even be caused by the same issue.

[Nekhelesh Ramananthan (nik90)]

Joshua, I think you may be correct. However I suggest that we wait for the merge proposal https://code.launchpad.net/~uonedb-qt/u1db-qt/ordering2/+merge/184350 to land in the PPA. If it solves this bug we mark it as a duplicate of your bug, else this is a different issue.

As a side note, try running example 5 again without any modifications. I now get a different output to the one you got :). I get only the first 3 entries. The others are missing unlike what you saw.

[David Planella (dpm)]

I've been hinted that this affects the Ability to sync playlists in the Music app, thus adding a bug task to keep track of that.

[David Planella (dpm)]

@Music app devs, could you provide some more context as to how exactly the Music app is affected by this bug and set the Importance field for it? Thanks!

[Andrew Hayzen (ahayzen)]

This is required for the implementation of playlists within the music-app.

The following structure is currently used:

{
    "playlist": {
        "name": "test",
        "tracks": [
            {"file": "abc", "title": "A"},
            {"file": "def", "title": "D"}
        ]
    }
}

However using an index with an expression of ["playlist.name", "playlist.tracks.file", "playlist.tracks.title"] or ["playlist.name", "playlist.tracks"] doesn't work as expected, as stated in the bug description.

[PS Jenkins bot (ps-jenkins)]

Fix committed into lp:u1db-qt at revision 112, scheduled for release in u1db-qt, milestone 1.0

[Launchpad Janitor (janitor)]

This bug was fixed in the package u1db-qt - 0.1.5+14.04.20140313-0ubuntu1

---------------
u1db-qt (0.1.5+14.04.20140313-0ubuntu1) trusty; urgency=low

  [ CI bot ]
  * No change rebuild against Qt 5.2.1.

  [ Christian Dywan ]
  * Adopt xvfb.sh script from ui toolkit to run tests
  * Sort out build warnings and make them always fatal.
  * Implement Database.removeDoc method and use it in unit test
    Functionally this is equivalent to replacing the doc with an empty
    one. (LP: #1243395)
  * Use new-style qmlrunner log option to enable stdout.
  * Query improvements and more advanced example. (LP: #1271977,
    #1271972, #1266478)
  * Store whole document contents in the results and unit test that.
    (LP: #1271973)
  * Reverse query logic to check non-matching and internally convert
    between query syntaxes. (LP: #1284194, #1214538, #1215898)
  * Revert r113 and update unit test to verify previous behavior
 -- Ubuntu daily release <email address hidden> Thu, 13 Mar 2014 23:12:40 +0000