On 2014/03/02 19:13, Tim Sutton wrote:
Hey Zoltan
Hi Tim,
Long time no chat......
On Sun, Mar 2, 2014 at 4:59 PM, Zoltan Szecsei <zolt...@geograph.co.za
<mailto:zolt...@geograph.co.za>> wrote:
8<---------------------snip---------------------------------
Please consider this methodolgy:
Currently, when QGIS loads a map layer, certain default things
happen: Styles get assigned, etc etc.
As a maplayer is loaded (or perhaps only when the user changes
something (like style)), QGIS should dump a [maplayername].qgis
file, text format, perhaps keyword-value layout, into the
directory that the map is stored. This file will then contain all
the internal QGIS defaults, and of course updates to the current
(style ) status, as the user changes them.
The benefits of using this implementation scheme could be vast:
* For deployment purposes, users could create/edit this file
outside of QGIS
* QGIS Dev could implement a methodology whereby user scripts
could read and write to this maplayer specific file - for
example: map production information whilst capture staff are
creating features.
* This file could even be designed to live at the project level,
and at the user level - this way departmental level defaults
could be set (deployed), and for those users who need it,
these could be over-ridden by having that filename als local
to the user, but with user specific values.
* Should any of these filenames only have some of the default
keyword-values, QGIS could look for the other defaults at
higher filename level (ie project level if user-level does not
exist), or as currently, at the internally stored default actions.
And the downsides could be (if I understand your proposal correctly):
* Working on a shared file store you are going to wreak all kinds of
havoc with user experience as different users overwrite the same file
concurrently
Too true. But that's the same as if two users tried to edit the same map
layer on a central server, from two different clients, so it would have
to be implemented with the same locking or shared update mechanism that
the map layer itself is enjoying.
* Working with a read only directory it obviously wont work
duh... :-)
* Working with remote datasources (PostGIS etc.) it won't work
Yes, there will always be situations where this won't work, but then
QGIS could fall back to it's current methodology.
The above implementation strategy would not need a special
"export" menu as the information would then always be stored in a
user useable file.
If this file becomes corrupt or nonsensical, QGIS actions could
revert to the default internal actions.
As time goes by, I reckon QGIS developers would find many more
uses for this map-layer specific file mechanism, should it be
available.
Hope I'm making sense.
Not completely for me :-)
True - my fault. I work with simplistic file types (mainly shape-files),
as my clients dictate what I have to capture and deliver in. This
mechanism would work well for Shape files, because they don't support
concurrent editing, and thus the .qgis file I am thinking of, would also
not have to worry about concurrent updates.
Incidentally, I implemented exactly this sort of status tracking with
scripts in my proprietary GIS package, and it worked really well, so,
truth be told, I am missing this facility when using QGIS.
Cheers for now,
Z
Regards
Tim
Kind regards,
Zoltan
--
===========================================
Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
GIS and Photogrammetric Service
P.O. Box 7, Muizenberg 7950, South Africa.
Mobile:+27-83-6004028 <tel:%2B27-83-6004028>
Fax:+27-86-6115323 <tel:%2B27-86-6115323> www.geograph.co.za
<http://www.geograph.co.za>
===========================================
_______________________________________________
Qgis-developer mailing list
Qgis-developer@lists.osgeo.org <mailto:Qgis-developer@lists.osgeo.org>
http://lists.osgeo.org/mailman/listinfo/qgis-developer
--
Tim Sutton - QGIS Project Steering Committee Member
==============================================
Please do not email me off-list with technical
support questions. Using the lists will gain
more exposure for your issues and the knowledge
surrounding your issue will be shared with all.
Irc: timlinux on #qgis at freenode.net <http://freenode.net>
==============================================
--
===========================================
Zoltan Szecsei PrGISc [PGP0031]
Geograph (Pty) Ltd.
GIS and Photogrammetric Service
P.O. Box 7, Muizenberg 7950, South Africa.
Mobile: +27-83-6004028
Fax: +27-86-6115323 www.geograph.co.za
===========================================
_______________________________________________
Qgis-developer mailing list
Qgis-developer@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-developer
