[Qgis-developer] [Qgis-user] Processing Feature Request(?): 'sticky parameters' AND generic settings....

Victor Olaya volayaf at gmail.com
Sat Oct 17 07:15:06 PDT 2015

There is currently no option in Processing to do that, and you should
probably add that logic to the algorithm itself (like for instance, if
the value of the parameter is equal to the default value, it should be
replaced with the last value, which should be itself stored by the
algorithm or taken from the Processing history)

I suggest adding a feature request, so this idea is not forgotten.

About the common functions, I definitely agree with that. It will also
help plugins look more homogeneous (and most likely, more stable). The
qgis.utils module looks like a good place to put all this functions.

More important that implementing those functions would be to actually
document them and make sure people know about them (the obvious place
to write about them is the PyQGIS cookbook), and try to enforce using
them in plugins.

I have quite a few general functions that I use for several plugins. I
wouldn' mind adding them to qgis.utils (or any other core module that
we agree on using for this) and if anyone does the same, I think we
can end up with a nice collection of them.


2015-10-17 11:40 GMT+02:00 Alexander Bruy <alexander.bruy at gmail.com>:
> Hi Richard,
> I think your question is more suitable for developers list (cc-ing).
> AFAIK, such behavior currently not available in Processing, but
> I think this is good addition. If I'm not wrong we already even have
> similar feature request.
> Also I agree that having some utilities class for common operations
> in C++ code with Python bindings will be useful.
> 2015-10-17 11:45 GMT+03:00 Richard Duivenvoorde <rdmailings at duif.net>:
>> Hi, not sure if I ask something which is already available (then please
>> let me know how), or else I ask for the following:
>> I have a model which runs some scripts.
>> This model takes as input some x,y,value file coming from an external
>> appliation.
>> For a given area this external app (actually a real mathamatical
>> 'model') is ran several times given different parameters and the result
>> is visualized in QGIS by showing the xy values, creating contours and
>> styling it in some ways.
>> So the scripts in the processing model for given area has several
>> 'fixed' parameters. Eg the boundaries in the contour script for a given
>> area are always the same. Or the 'load script' also has some inputs
>> which are always the same.
>> So in the different script you have input variables like:
>> ##minval=number 0
>> ##maxval=number 3000
>> BUT using this script in a model, I do not want to set the values
>> everytime. In the model it is exactly the same: I can set input values,
>> but they are not 'remembered' in between following runs.
>> So my idea (as said: please tell me if it is already there):
>> Can we have something like
>> ##minval=number 0 sticky
>> ##maxval=number 3000 sticky
>> My idea is that as soon as this script is ran, the 'default values' are
>> set to the last used values.
>> So NO value availabe: use the default one (eg 3000 for maxval), but as
>> soon as the user has changed this to say 2500, that value is saved in
>> the QSettings somewhere, and next time the script (or model) is ran, the
>> default value will be 2500
>> Idea? Or already available?
>> Which brings me to the following, which I think is usefull for python
>> devs, but I think also for cpp code.
>> Why do we not have some utils class which holds some pretty often used
>> code. What I now think of:
>> - save a value in settings with given key
>> - load a (cast to certain type) value from setting with given key and if
>> not available provide a default something like (the type part not yet in
>> it):
>>     def get_settings_value(self, key, default=''):
>>         if QSettings().contains(self.SETTINGS_SECTION + key):
>>             key = self.SETTINGS_SECTION + key
>>             val = QSettings().value(key)
>>             return val
>>         else:
>>             return default
>>     def set_settings_value(self, key, value):
>>         key = self.SETTINGS_SECTION + key
>>         QSettings().setValue(key, value)
>> I see know so many places where there this is implemented...
>> Or another one which I think should be centralized:
>> - the saving and opening of 'current directory'...
>> We have a lot of dialogs which open a file manager, but a lot of them
>> open in pretty weird places (like some directory in the installation
>> folder).
>> I think it is better if we come up with some 'reasonable' places like:
>> - current project folder
>> - last data folder
>> And implement those as util methods like to be used as opening places
>> for the file dialogs.
>> Opinions and or other ideas?
>> Regards,
>> Richard Duivenvoorde
>> _______________________________________________
>> Qgis-user mailing list
>> Qgis-user at lists.osgeo.org
>> http://lists.osgeo.org/mailman/listinfo/qgis-user
> --
> Alexander Bruy
> _______________________________________________
> Qgis-developer mailing list
> Qgis-developer at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-developer

More information about the Qgis-developer mailing list