DBManager fails to display error messages with virtual layers

[qgib]

Author Name: Regis Haubourg (@haubourg)
Original Redmine Issue: 20193
Affected QGIS version: 3.3(master)
Redmine category:db_manager
Assignee: Alessandro Pasotti

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In QGIS master, error messages when trying to work with virtual layers are no more catched.

IN QGIS 2.1, just issuing a wrong query like

SELECT *

returned a window with

Query preparation error on PRAGMA table_info(_tview): no tables specified

In QGIS master, this error window is empty.

[qgib]

Author Name: Regis Haubourg (@haubourg)

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Also occurs in QGIS 3.2.2

[qgib]

Author Name: Alessandro Pasotti (@elpaso)

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• assigned_to_id was configured as Alessandro Pasotti

[qgib]

Author Name: Giovanni Manghi (@gioman)

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as far as I remember it does not affect only virtual layers-

[qgib]

Author Name: Hugo Mercier (@mhugo)

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From what I can see, there is at least the following problem:

bool QgsVirtualLayerTask::run()
{
  bool rc = false;
  try
  {
    mLayer->reload(); // blocking call because the loading is postponed
    rc = mLayer->isValid();
  }
  catch ( std::exception &e )
  {
    QgsDebugMsg( QStringLiteral( "Reload error: %1" ).arg( e.what() ) );
    rc = false;
  }
  return rc;
}

The error is catched and displayed in a QgsDebugMsg. It seems there is no way to set an error status on a qgstask ?

[qgib]

Author Name: Alessandro Pasotti (@elpaso)

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PR #8283

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• status_id was changed from Open to In Progress
• pull_request_patch_supplied was changed from 0 to 1

[qgib]

Author Name: Alessandro Pasotti (@elpaso)

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Sorry Hugo, I didn't see your comment before I made the PR.

Yes: there is no way to store an error message, that's why there is a wrapper for that in code: https://github.com/qgis/QGIS/blob/master/python/core/additions/qgstaskwrapper.py

I'm not sure what would be the best re-usable approach here but the bugfix I've implemented was exactly to add exceptionText to the task in order to store the error message.

[qgib]

Author Name: Hugo Mercier (@mhugo)

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No problem :)

[qgib]

Author Name: Alessandro Pasotti (@elpaso)

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Implemented with #8283

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• resolution was changed from to fixed/implemented
• status_id was changed from In Progress to Closed