API versioning broken in some cases

[Chris Coulson]

With Oxide 1.2 being the version that's shipping in the RTM image, I want to start correctly versioning new API's so that we can upgrade Oxide OTA safely without breaking existing applications. I'm testing the attached patch for Oxide to add a revision to API's that were added in 1.3, but running the test suite results in the following failure:

Output:
----------------------------------------------------------
file:///home/chr1s/src/oxide/oxide/qt/tests/qmltests/core/tst_CustomURLSchemes.qml:11:11: ".allowedExtraUrlSchemes" is not available due to component versioning.
       context.allowedExtraUrlSchemes: [ "test", "bar" ]
               ^
********* Start testing of qml-core-test *********
Config: Using QtTest library 5.3.0, Qt 5.3.0
QWARN : qml-core-test::tst_CustomURLSchemes::compile()
  /home/chr1s/src/oxide/oxide/qt/tests/qmltests/core/tst_CustomURLSchemes.qml produced 1 error(s):
    /home/chr1s/src/oxide/oxide/qt/tests/qmltests/core/tst_CustomURLSchemes.qml:11,11: ".allowedExtraUrlSchemes" is not available due to component versioning.
  Working directory: /home/chr1s/src/oxide/oxide/objdir/qt/tests/qmltests
  View: QQuickView, import paths:
    '/home/chr1s/src/oxide/oxide/objdir/out/bin'
    '/home/chr1s/src/oxide/oxide/objdir/out/imports'
    '/usr/lib/x86_64-linux-gnu/qt5/qml'
  Plugin paths:
    '.'

FAIL! : qml-core-test::tst_CustomURLSchemes::compile() ".allowedExtraUrlSchemes" is not available due to component versioning.
   Loc: [/home/chr1s/src/oxide/oxide/qt/tests/qmltests/core/tst_CustomURLSchemes.qml(11)]

After scratching my head for a while, I can't see what I'm doing wrong here.

If I run the following simple QML app, I can access the property correctly:

- test.qml:

import QtQuick 2.0
import com.canonical.Oxide 1.3

WebView {
  focus: true
  width: 960
  height: 540

  url: "https://www.google.com"

  context: WebContext {
    allowedExtraUrlSchemes: []
  }
}

However, if I run this simple app instead, then it fails with the same message I see in the unit tests:

- test.qml:

import QtQuick 2.0
import com.canonical.Oxide 1.3

TestWebView {
  focus: true
  width: 960
  height: 540

  url: "https://www.google.com"

  context.allowedExtraUrlSchemes: []
}

- TestWebView.qml

import QtQuick 2.0
import com.canonical.Oxide 1.3

WebView {
  context: WebContext {}
}

This last example works fine without a revision number on this API.

I consider this to be a blocker for being able to update Oxide OTA, as we're not able to version new API's with this bug

Upstream bug https://bugreports.qt.io/browse/QTBUG-40043 is related to this one.

[Chris Coulson (chrisccoulson)]

This sounds similar to https://bugreports.qt-project.org/browse/QTBUG-40043

[Cris Dywan (kalikiana)]

I notice

+ qmlRegisterType<OxideQQuickWebContext, 1>(uri, 1, 3, "WebContext");

the template argument passing the revision there - in the UITK we have versioning but we don't use that one. Also, shouldn't it be 3?

[Chris Coulson (chrisccoulson)]

Not exactly - the "1" matches the revision number specified in the metadata in the class declarations. Eg,

--- qt/quick/api/oxideqquickwebcontext_p.h 2014-10-09 20:22:21 +0000
+++ qt/quick/api/oxideqquickwebcontext_p.h 2014-11-05 00:22:04 +0000
@@ -60,9 +60,9 @@

   Q_PROPERTY(OxideQQuickCookieManager* cookieManager READ cookieManager CONSTANT)

- Q_PROPERTY(QStringList hostMappingRules READ hostMappingRules WRITE setHostMappingRules NOTIFY hostMappingRulesChanged)
+ Q_PROPERTY(QStringList hostMappingRules READ hostMappingRules WRITE setHostMappingRules NOTIFY hostMappingRulesChanged REVISION 1)

- Q_PROPERTY(QStringList allowedExtraUrlSchemes READ allowedExtraUrlSchemes WRITE setAllowedExtraUrlSchemes NOTIFY allowedExtraUrlSchemesChanged)
+ Q_PROPERTY(QStringList allowedExtraUrlSchemes READ allowedExtraUrlSchemes WRITE setAllowedExtraUrlSchemes NOTIFY allowedExtraUrlSchemesChanged REVISION 1)

   Q_ENUMS(CookiePolicy)
   Q_ENUMS(SessionCookieMode)
@@ -164,8 +164,8 @@
   void devtoolsEnabledChanged();
   void devtoolsPortChanged();
   void devtoolsBindIpChanged();
- void hostMappingRulesChanged();
- void allowedExtraUrlSchemesChanged();
+ Q_REVISION(1) void hostMappingRulesChanged();
+ Q_REVISION(1) void allowedExtraUrlSchemesChanged();

  private:
   Q_PRIVATE_SLOT(d_func(), void userScriptUpdated());

[Zsombor Egri (zsombi)]

Actually we have revisions and we use the same declaration for components in UI Toolkit as well. And the revisioning of ViewItems attached properties are also broken, see https://code.launchpad.net/~zsombi/ubuntu-ui-toolkit/listitem-expansion/+merge/254375, where I had to do an ugly workaround to get the revisioned API accepted in Expansion.qml test code.

[Timo Jyrinki (timo-jyrinki)]

Could you bring the problem to upstream's attention via https://bugreports.qt.io/ ? I tried to search for existing similar bug reports but didn't find one. Possibly some better keyword would help in searching though.

[Zsombor Egri (zsombi)]

+Chris, so to give more help, the workaround:
1) create a new class which derives from the one you want to expose the revisioned API
2) move all your revisioned API into this one
3) register the new class to the version you need with the same name as in the previous version

From the upstream bug it looks like everything registered with qmlRegisterUncreatableType<type_name, revision>() breaks the versioning. We need to keep this workaround till the bug is fixed.

[Zsombor Egri (zsombi)]

+Timo, the bug is in Chris' comment #2. I'll add to the description.

[Timo Jyrinki (timo-jyrinki)]

Thanks, /me blind and blaming DST. Thanks for commenting more on the upstream report, maybe it gets a bit of visibility.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Timo Jyrinki (timo-jyrinki)]

https://codereview.qt-project.org/#/c/146588/ is now merged to Qt 5.6.

[Timo Jyrinki (timo-jyrinki)]

More related bugs:
https://bugreports.qt.io/browse/QTBUG-50990
https://bugreports.qt.io/browse/QTBUG-48966