[GRASS-dev] Re: gis.m: error message when trying to add layer without open map display

[Michael Barton]

Good idea, but considerably more work to program this.

Michael


On 2/8/07 4:57 PM, "Hamish" <hamish_nospam at yahoo.com> wrote:

> Moritz:
>>> Since you have been busy working on error catching in gis.m: I've
>>> always found that the error that occurs when you try to add a layer
>>> even though there is no open map display quite difficult to
>>> understand for newbies:
>>> 
>>> invalid command name
>>> ".mainframe.frame.pw1.f0.frame.pgs.fpage_1.sw.tree_1" invalid
>>> command name ".mainframe.frame.pw1.f0.frame.pgs.fpage_1.sw.tree_1"
>>>      while executing
>>> "$tree($mon) selection get"
> ..
>>> Would it be possible to catch this and produce a nicer error message
>>> such as: "You need to open a map display first." ?
> 
> Michael:
>> I'll try to see what's going on with this. It probably has to do with
>> the necessary link between a layer tree and a display. A better error
>> message would likely be "You need to open a display before adding map
>> layers"
> 
> Even better: Don't bother with error messages, do what the user wanted:
> open a new display if needed & add the layer.
> 
> 
> Hamish

__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton