[Qgis-developer] [GRASS-dev] QGIS GRASS Plugin Upgrade Crowdfunding

[Sören Gebbert]

Hi Radim,

2015-03-24 9:40 GMT+01:00 Radim Blazek <radim.blazek at gmail.com>:
> Hi Soeren,
> thanks for your reaction. I remember we already discussed the
> possibility to move to Python.
>
> On Mon, Mar 23, 2015 at 9:19 PM, Sören Gebbert
> <soerengebbert at googlemail.com> wrote:
>> Hi Radim,
>> this is a beautiful idea and i hope you will get plenty of funds.
>>
>> I have some questions regarding the implementation, since this is not
>> mentioned in the project description:
>>
>> Do you plan to implement the plugin in C++ only, or will you try to
>> combine C++ (data provider) and Python (all the rest)? The reason i am
>> asking is, that using Python for the user interaction, module calling,
>> vector editing and mapset/location handling would allow us GRASS
>> developer to provide possible improvements and bugfixes for the plugin
>> more easily. For example, the time series handling [1] in GRASS GIS is
>> mainly implemented in Python and provides a Python API that could be
>> used in the QGIS GRASS Plugin to implement time series analysis
>> support.
>> Using the QGIS Python plugin approach will reduce the need for
>> compilation, which allows much faster development of modifications and
>> bugfix testing.
>
>
> I completely agree that Python would be better, the advantages of
> Python are obvious and that would be definitely my choice if I had to
> start from scratch. Un(fortunately) the GRASS plugin + qgsgrassgislib
> have already 22500 lines of C++ so porting to Python is not an option
> and mixing C++ in single plugin either (as far to my knowledge).

Indeed, porting the C++ code to Python is a large effort. However,
maybe you can define a stretch-goal in the crowd funding campaign? If
this goal is met, then you have enough funds to port the C++ code to
Python and you can add more features?

I think that using C++ and Python in a Plugin shouldn't be a big
problem in my humble opinion. The main issue would be that the C++
code of the data provide will be part of QGIS and the Python code that
makes use of the GRASS data provider will be a separate GRASS Python
QGIS plugin. Maybe this approach will allow to implement several
independent Python plugins that make use of the GRASS data provider to
implement specific algorithms?

> Are there functions in time series implementation which need to be
> called directly from the plugin or everything may be done just calling
> t.rast.* modules?

Most of the temporal functionality is available through the temporal
modules. However some important algorithms (temporal re-sampling) are
available only in the Python framework. This is needed for time series
animation creation. Using the framework directly will speed things up,
because the module calls, the parsing and interpretation of the module
outputs can be avoided.

Many thanks for the QGIS GRASS Plugin
Best regards
Soeren

> Radim
>
>> The data provider and vector editing helper classes must be of course
>> implemented in C++ and should stay in the QGIS source tree.
>>
>> Best regards
>> Soeren
>>
>> [1] http://ifgi.uni-muenster.de/~epebe_01/tgrass.pdf
>>
>> Btw: Otto Dassau and i mentioned your crowd funding idea at the
>> FOSSGIS in Germany two weeks ago. It is on Youtube[2] but only in
>> German.
>>
>> [2] https://www.youtube.com/watch?v=rxmPbh2igmM&t=1407
>>
>> 2015-03-23 19:56 GMT+01:00 Radim Blazek <radim.blazek at gmail.com>:
>>> Hi all,
>>>
>>> I have finally launched the crowdfunding campaign to support the GRASS
>>> plugin upgrade. Briefly, it covers upgrade to GRASS 7, browser
>>> integration, drag-and-drop import and new vector editing. All the
>>> details are available here:
>>>
>>>     http://www.gissula.eu/qgis-grass-plugin-crowdfunding/
>>>
>>> Please propagate this info to all relevant channels, national mailing lists etc.
>>>
>>> Radim
>>> _______________________________________________
>>> grass-dev mailing list
>>> grass-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/grass-dev