[Qgis-user] Automatically force reload layer from source (geojson)

[Richard Duivenvoorde]

Mmm, thinking out loud here; actionslike 'disable cache' per layer, or
'refresh layer every x minute' are more functions for the view, isn't it?
As: a provider should just do what it suppossed to do: either fetch all
data (like you do with a geojson url) or a part of it (like you do with
a wfs or postgres provider which only fetch within a bbox)...

I've been a (potential fan) of Martin's work about 'Embedded Layer
Widgets', see
http://www.qgis.nl/2019/02/14/about-layer-tree-embedded-widgets-and-have-your-wmts-always-crispy-sharp/?lang=en
Martin's example there was an opacity slider, and I created a slider to
always click to fixed scales.

But I think with not so much work it should be possible to create a
widget (in python, AND package it as a normal QGIS plugin) with
functionality like: refresh every x (input) seconds, or create a
'refresh' button in the Layermanager...

What you think?

Regards,

Richard

On 22/11/2019 23.55, Olivier Dalang wrote:
> Hah !! Indeed ! F5 works as you say... No idea how I missed this !
> 
> Thanks !! :-)
> 
> However, geojsons don't update here (win 10) without F5, even when
> panning. It would be nice to be able to disable cache completely per
> layer, and/or allow to have "refresh layer at interval" also reload from
> source. What do you think? Should I open a feature request ?
> 
> Cheers,
> 
> Olivier
> 
> 
> 
> On Fri, 22 Nov 2019 at 23:32, Mike Flannigan <mikeflan at att.net
> <mailto:mikeflan at att.net>> wrote:
> 
> 
>     That is correct.  On Win7 I just zoomed in or out
>     after the file was revised and it updated to the
>     new geoj immediately.  I did not try F5, but that
>     should work also.
> 
>     I am now on Linux Mint.  Let me know if you want
>     me to check it on this system.
> 
> 
>     Mike
> 
> 
>     On 11/22/19 2:00 PM, qgis-user-request at lists.osgeo.org
>     <mailto:qgis-user-request at lists.osgeo.org> wrote:
>>     Date: Fri, 22 Nov 2019 14:38:33 +0100
>>     From: Richard Duivenvoorde <rdmailings at duif.net> <mailto:rdmailings at duif.net>
>>     To: Olivier Dalang <olivier.dalang at gmail.com> <mailto:olivier.dalang at gmail.com>, qgis-user
>>     	<qgis-user at lists.osgeo.org> <mailto:qgis-user at lists.osgeo.org>
>>     Subject: Re: [Qgis-user] Automatically force reload layer from source
>>     	(geojson)
>>
>>
>>     Hi Olivier,
>>
>>     Does F5 (refresh, from menu 'View/Refresh') not work?
>>
>>     I thought that when I had an (live changing) online geojson source, (and
>>     added as url), I could easily 'reload' fresh data via F5
>>
>>     Not working for you?
>>
>>     Regards,
>>
>>     Richard Duivenvoorde
>>
>>
>>
>>     On 22/11/2019 14.12, Olivier Dalang wrote:
>>>     Dear list,
>>>
>>>     Currently, when I load a geojson into QGIS, and modify the geojson file
>>>     using an other software, the change isn't reflected in QGIS. The only
>>>     way to reflect the change is to re-add the layer, or to run
>>>     `iface.activeLayer().dataProvider().forceReload()` in the python console.
>>>
>>>     I see could find neither a button or menu to trigger a reload manually,
>>>     nor the option to do it automatically, nor a way to disable caching of
>>>     such layers (which anyway would be suitable for very small layers only).
>>>
>>>     Ideally, I was looking for an option like the "refresh layer at
>>>     interval" options from the layer properties>rendering dialog (that
>>>     option seems to just re-render the file, without reloading it, so that
>>>     it doesn't work for my purpose).
>>>
>>>     Thanks !
>>>
>>>     Olivier
> 
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