[QGIS-Developer] Qt Model-View updates blocked when Python console not open

[Peter Devoy]

Hi guys

Thank you all for your suggestions.   Calls to print() triggering
QCoreAppliation::processEvents() explains the phenomena and I was able
to fix using the Boundless's QNetworkAccessManager wrapper instead of
the requests library.

Thanks again!


Peter

On 6 October 2017 at 07:41, Richard Duivenvoorde <rdmailings at duif.net> wrote:
>
>
> And to make things easier, use
>
> https://github.com/boundlessgeo/lib-qgis-commons/blob/master/qgiscommons2/network/networkaccessmanager.py
>
> which should be core class in QGIS if you ask me. So we can get rid of
> all other different blocking/nonproxying etc ways to connect QGIS to http...
>
> Regards,
>
> Richard Duivenvoorde
>
> On 05-10-17 22:01, Ricardo Filipe Soares Garcia da wrote:
> > Hi Peter
> >
> > In addition to Matthias' advice perhaps try using
> > QNetworkAccessManager[1] and related classes in order to deal with your
> > http requests asynchronously. This should fix the UI blocking issues.
> >
> > Best regards
> >
> >
> > [1]
> > - http://pyqt.sourceforge.net/Docs/PyQt4/qnetworkaccessmanager.html#details
> >
> >
> > Em 05/10/2017 15:18, "Matthias Kuhn" <matthias at opengis.ch
> > <mailto:matthias at opengis.ch>> escreveu:
> >
> >     Hi Peter,
> >
> >     Have a look at this answer here, which explains how you can trigger
> >     the same behavior without using the print and relying on
> >     side-effects of the console open.
> >
> >     It also outlines the risks involved in using this kind of approach.
> >
> >     https://gis.stackexchange.com/a/257016
> >     <https://gis.stackexchange.com/a/257016>
> >
> >     Cheers
> >     Matthias
> >
> >
> >     On 10/05/2017 03:25 PM, Peter Devoy wrote:
> >
> >         Just a little update; it is the fact I am using print() to output
> >         debug information upon each request which is allowing the UI to
> >         repaint.  Also, it seems that opening and closing the Python console
> >         once is enough.
> >
> >         Peter
> >
> >         3XE
> >         P: 01326 567155
> >         M: 07770 693662
> >         A: 3XE Ltd
> >         Tremough Innovation Centre
> >         PENRYN
> >         TR10 9TA
> >         3XE Ltd · Registered in England and Wales · 9356871
> >
> >
> >         On 4 October 2017 at 20:53, Peter Devoy <peter at 3xe.co.uk
> >         <mailto:peter at 3xe.co.uk>> wrote:
> >
> >             Hi all
> >
> >             In my plugin I have extended QAbstractListModel to create a
> >             list of
> >             objects; each object in the list has a 'url' property
> >             containing the
> >             URL of an API resource.  When the user selects a feature in
> >             main QGIS
> >             interface, each object in the list makes a HTTP request to
> >             its URL and
> >             updates its properties from the response data.
> >
> >             Changes in the objects' properties are reflected in a
> >             QListView.  E.g.
> >             a  property 'status'  is set to 'WARN' if the HTTP request
> >             fails --
> >             this is reflected in the QListView by the respective list
> >             item's icon
> >             turning yellow.
> >
> >             If I have the Python console open in QGIS the QListView
> >             items update
> >             as the ListModel's objects update. However, if the Python
> >             console is
> >             not open, the plugin's UI thread appears to be blocked until
> >             each item
> >             in the list has completed its changes and all the items
> >             update at
> >             once; please can anyone recommend a way to avoid this?
> >
> >             I have been developing on QGIS 2.1X.
> >
> >             Kind regards
> >
> >
> >             Peter
> >
> >         _______________________________________________
> >         QGIS-Developer mailing list
> >         QGIS-Developer at lists.osgeo.org
> >         <mailto:QGIS-Developer at lists.osgeo.org>
> >         List info:
> >         https://lists.osgeo.org/mailman/listinfo/qgis-developer
> >         <https://lists.osgeo.org/mailman/listinfo/qgis-developer>
> >         Unsubscribe:
> >         https://lists.osgeo.org/mailman/listinfo/qgis-developer
> >         <https://lists.osgeo.org/mailman/listinfo/qgis-developer>
> >
> >
> >     _______________________________________________
> >     QGIS-Developer mailing list
> >     QGIS-Developer at lists.osgeo.org <mailto:QGIS-Developer at lists.osgeo.org>
> >     List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> >     <https://lists.osgeo.org/mailman/listinfo/qgis-developer>
> >     Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> >     <https://lists.osgeo.org/mailman/listinfo/qgis-developer>
> >
> >
> >
> >
> > _______________________________________________
> > QGIS-Developer mailing list
> > QGIS-Developer at lists.osgeo.org
> > List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> >
>
> _______________________________________________
> QGIS-Developer mailing list
> QGIS-Developer at lists.osgeo.org
> List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer
> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer