[QGIS-Developer] is_layer_active expression

[Otto Dassau]

thanks for the info Nyall!

Regards, 
Otto

Am Tue, 25 Sep 2018 16:37:38 +1000
schrieb Nyall Dawson <nyall.dawson at gmail.com>:

> On Mon, 24 Sep 2018 at 19:20, Otto Dassau <dassau at gbd-consult.de> wrote:
> >
> > Dear Devs,
> >
> > in QGIS 3 I found the expression "is_layer_active" within the copyright
> > decoration very useful. I would like to use this expression also within
> > the print composer, but it seems to be not available there.  
> 
> Confirmed -- fix incoming!
> 
> > Is this correct, are expressions not available all over QGIS within the
> > expression builder?  
> 
> Some expression functions/variables are "context dependent". E.g.
> is_layer_visible doesn't make any sense in expressions which aren't
> directly associated with a map. So the function won't be available as
> for expressions used as a field default value, or for a layout text
> label (since the layout may have multiple maps, each with a different
> layer set, and a label isn't linked to any map item in particular!).
> 
> > And how can I get this expression working for the print composer as
> > well?  
> 
> Wait for 3.4 ;)
> 
> Nyall