[Qgis-developer] Re: QGIS Processing Framework

[Martin Dobias]

On Wed, Mar 21, 2012 at 7:23 PM, CzendaZdenda <tramtara at seznam.cz> wrote:
> If there is possibility that output parameter of the module can have any
> type, how can I handle with modules' outputs? Or just raster/vector layers
> are outputs?
>
> I mean how can I keep outputs after execution of module (
> processing.Framework['module'].execute() ). I am working on 'workflow
> builder'. I can connect modules or set values by myself. Now I want execute
> whole 'graph', so that's why I need to keep outputs.
>
> I was looking at present modules and types of output are just raster/vector
> layers or the basic type Parameter. So is there possibility that output type
> could be something like string, bool, int...?

Hi,

in my view any parameter type that could be specified as an input
should be allowed also for output - not just layers. For example: a
module that does statistics on a layer and returns mean and standard
deviation - these would be just two scalar output values and could be
used by some other module. In general, both inputs and outputs should
ideally be treated the same way: they are variables (parameters) of
some type and with some value.

I would suggest to store the results in the module which calculated
them - other modules that use those result would ask the module.

Cheers
Martin