[GRASS-dev] Future of external Processing providers in QGIS

[Markus Neteler]

Hi Paolo,

(reducing to grass-dev)

thanks for your detailed summary! I have just added a related agenda item to
https://grasswiki.osgeo.org/wiki/GRASS_GIS_Community_Sprint_Bonn_2018#Agenda_-_What_we_plan_to_do

A few more comments inline:

On Fri, Feb 23, 2018 at 3:26 PM, Paolo Cavallini <cavallini at faunalia.it> wrote:
> Hi all,
> meeting has just ended. I must say it was a very interesting and
> productive discussion. We are really grateful for the developers from
> GRASS, SAGA and OTB for their contributions to our discussion.

Glad that this discussion happened, paving the way to a continued
collaboration on the processing providers.

> I recap briefly here what I believe are the most important outcomes:
> * we'll keep SAGA and GRASS Processing providers

Excellent.

[... SAGA ... OTB...]

> * While we have granted an exception to the ‘processing providers should
> not be in core’ for the short term, our longer term plan is to put in
> place mechanisms to ‘side load’ the dependencies (GRASS, OTB, SAGA).
> When this capability is implemented, we will mandate that all providers
> will be provided as plugins and then fetch these plugins on demand if an
> algorithm references them

... I am not sure if I understand the details here but others in the
list certainly do :)

[... about future new backends...]

> * for future versions we will consider moving providers to the XML
> approach where appropriate, as it appears more maintainable, even at the
> expense of flexibility in interface tuning; GRASS is the next candidate,
> noting that this might require some modifications in GRASS core

There was already the proposal to add --qgis-description or likewise
into the parser of GRASS, should be doable.
This we will discuss next month in Bonn.

> * as a first step in we ask anybody to test thoroughly the new SAGA
> provider by Alex Bruy
> https://github.com/alexbruy/processing-saga
> also a check from SAGA, GRASS, and OTB devs would be important, to check
> whether this approach is the preferred one from all sides.

Thanks, we'll go through that.

> Please add if I missed something.
> Overall, I think we have now a brighter future for Processing, and as a
> consequence for QGIS, SAGA, GRASS and OTB altogether.

Thanks for your efforts of summarizing the important discussion.

Best
Markus