[Qgis-user] processing script vs. processing plugin (Ari Jolma)

[Andreas Plesch]

This is very helpful. I will take a look at the Perl provider plugin to
understand better what its role is.

I think without the plugin it is still possible to construct a perl command
line, Popen it, and read back the output from within a regular python
processing script but much less convenient. Although it may be possible to
write a python package with commonly used functionality to make this
approach also convenient (import perlprocessing).

It looks there are quite​ a few other processing scripts on GitHub by
others which are not in QGIS-Processing. So it may make sense to have a
list decoupled from qgis but still curated depending on how responsively
QGIS-Processing is managed, eg. how PRs are accepted.

-Andreas

On Mar 13, 2017 8:38 AM, "Ari Jolma" <ari.jolma at gmail.com> wrote:

> 13.03.2017, 13:24, Andreas Plesch kirjoitti:
>
> Hi Ari,
>
> thanks for your providing your perspective.
>
> A difference is that a plugin can provide multiple processing algorithms
> whereas a script only one.
>
> Another cosmetic difference is that a plugin can be managed and published
> with the plugin manager.
>
> Do you think you could have written your processing algorithms using Perl
> tools as a collection of processing scripts ?
>
>
> I think I have made that... In the sense that the plugin
>
> https://plugins.qgis.org/plugins/perlprocessing/
>
> (still the initial version which is not much more than a proof-of-concept)
>
> I wrote allows me to write processing algorithms as processing scripts. An
> example is this script
>
> https://github.com/ajolma/GDALToolsWithPerl/blob/master/dijkstra.pl
>
> which has a few comment lines in the beginning. Those make the script
> usable as a processing algorithm within QGIS. However, it can be used from
> the command line too.
>
>
> What is a good way of publishing, advertising and serving collections of
> processing scripts ?
>
>
> That depends on the provider. This repository
>
> https://github.com/qgis/QGIS-Processing
>
> is AFAIK used by the default (Python script) and R script provider.
>
>
> Gists ? GitHub repos and rawgit ?
>
> Is there a curated list of published scripts, like an awesome qgis repo ?
>
>
> The above one. Or maybe you're referring to that one?
>
> If there's interest for Perl scripts I guess we could work out something.
>
> Ari
>
>
> Andreas
>
>
> Message: 7
> Date: Mon, 13 Mar 2017 09:24:17 +0200
> From: Ari Jolma <ari.jolma at gmail.com>
> To: qgis-user at lists.osgeo.org
> Subject: Re: [Qgis-user] processing script vs. processing plugin
> Message-ID: <8950e763-af35-1135-9b5d-43c57bcd3d05 at gmail.com>
> Content-Type: text/plain; charset="utf-8"; Format="flowed"
>
> To me it seems that processing algorithm provider plugins are language
> or tool specific plugins that add a new section to the processing.
> Processing is itself a plugin (although a core one).
>
> I don't think providers should add custom GUIs beyond what is needed to
> manage itself and the algorithms it provides. That is, its GUI is for
> adding, possibly creating, etc. algorithms. It should mostly work
> through the processing plugin.
>
> The "algorithms" are processing tools (scripts, external programs, etc)
> that only have a thin wrapper so that the provider plugin can help the
> processing plugin create a GUI for running it or linking it to other
> tools to create models.
>
> This is my understanding that I've gained by creating a provider plugin
> for Perl programs to be used as processing algorithms.
>
> I'm actually a bit against listing the providers separately since the
> user should not need to care what language or program the processing
> tool is written as long as it does what the user wants.
>
> Best regards,
>
> Ari
>
>
> 13.03.2017, 04:48, Andreas Plesch kirjoitti:
> > What are differences between processing algorithms provided as a
> > processing script or as processing algorithm provider plugin ?
> >
> > A plugin can presumably have its own custom GUI but are there are
> > other differences in available capabilities ?
> >
> > Andreas
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/qgis-user/attachments/20170313/e07ebada/attachment.html>