[GRASS-dev] gis.m bugs

[Glynn Clements]

Michael Barton wrote:

> The GIS Manager has no way of knowing that the data in the underlying vector
> file has been changed. The normal display will only re-render a layer if it
> has changed. This makes the display MUCH faster, but of course can be a
> problem if you have changed the data in the layer by some means. Hence, the
> new redraw all layers button.

At a minimum, gis.m should have an option to refresh a single layer
(i.e. discard any cached images for that layer).

Ideally, we need a g.timestamp module which returns the last-modified
time for a given entity (raster map, vector map, imagery group etc).

This essentially boils down to enumerating the files comprising a
given entity type (the details should already be present in g.remove
etc), obtaining the last-modified time for each, and returning the
most recent of those timestamps.

One possible complication: is there any way to determine when a vector
map was last modified? If not, this needs to be added; an empty file
which is updated whenever the vector map is modified should suffice
for most cases (obviously, we can't do anything about the user
manipulating the SQL database directly).

-- 
Glynn Clements <glynn at gclements.plus.com>