[Qgis-user] automatically reload (csv) file

[Dr. Marco Lechner]

Hi,

how (often) does QGIS read features from a file (like csv or shape -
differences?)? I realize I do not really know how the datasource - qgis-
communication goes.

Imaine you have a csv or shape file that is loaded into QGIS but is
automatically replaced from time to time (or lets say externally
edited). Using a database- instead of file-based approach is better for
sure, but still it is not clear when / how often (on which events) QGIS
requests features from the datasources.

As an idea in mind I see, the nice Sync-Plugin
(https://plugins.qgis.org/plugins/SyncQGISWithDir/) can monitor folders
and notify the user if a new layer is available in a folder (well it
does not take care of a changed layer (new timestamp of file, but adding
this functionality should not be such a big thing). The user could also
be notified when a layers file changed.

But I'm not sure what was the best way to implement the (re)loading of
an already loaded layer. Do I have to drop the layer and reload it
(including keeping the style) or is there a more efficient way?

Marco

-- 
Dr. Marco Lechner
Bundesamt fuer Strahlenschutz / Federal Office for Radiation Protection
SW2.1 Koordination Notfallschutzsysteme / Coordination Emergency Systems
Rosastrasse 9 | D-79098 Freiburg | Germany
mlechner at bfs.de | +49 (0)3018 333 6724 | www.bfs.de

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