Hi,<br><br>+1 for Mayeul Nathan. This "virtual column" would be a very handy tool ! E.G for labelling<br><br>kimaidou<br><br><div class="gmail_quote">2011/7/28 Andreas Neumann <span dir="ltr"><<a href="mailto:a.neumann@carto.net">a.neumann@carto.net</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Hi Nathan,<br>
<br>
Good to hear that you are working on this.<br>
<br>
I just wonder if it wouldn't make sense to have a general purpose "virtual column" that could be introduced in QGIS. This would be useful for:<br>
<br>
* labeling<br>
* map tips/QGIS server tooltip display<br>
* symbology<br>
* plugins<br>
* others?<br>
<br>
It would be convenient to use the field calculator, but instead of just writing out to a physically existing column it would create a new virtual column, just like a virtual column in a database view.<br>
<br>
Otherwise one would have to develop the same functionality several times - for labeling, for tooltips, etc.<br>
<br>
Do you think it would be feasible to implement this on a lower level in QGIS so that users could transparently work with virtual columns wherever they want?<br>
<br>
Andreas<br>
<br>
On Thu, 28 Jul 2011 16:09:56 +1000, Nathan Woodrow wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
My upcoming patch that adds expression based labels will be able<br>
to achieve this once it's completed; I'm just cleaning up the UI<br>
and testing everything then I will get the guys to merge it in.<br>
Until then you will need to create a new column.<br>
<br>
- Nathan<br>
<br>
On Wed, Jul 27, 2011 at 9:15 PM, Torsten Lange wrote:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Ok, thank you, Andreas!<br>
<br>
Torsten<br>
<br>
Am Mittwoch 27 Juli 2011, 11:00:01 schrieb Andreas Neumann:<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi,<br>
</blockquote>
><br>
> Currently, you have to create a new column. I usually create a<br>
view in<br>
> Postgis for this purpose.<br>
><br>
> It is in on the wishlist that one can create a "virtual" column<br>
- not<br>
> only for labeling, but also for map tips and perhaps<br>
symbolization.<br>
> Until then you have to do it yourself.<br>
><br>
> Andreas<br>
><br>
> On Tue, 26 Jul 2011 22:51:34 +0200, Torsten Lange wrote:<br>
> > Hi,<br>
> ><br>
> > Is there a way just to print - lets say - the first four<br>
letters of a<br>
> > objects<br>
> > name? Or must I create a new row for that?<br>
> ><br>
> > Thank you, Torsten<br>
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--<br><font color="#888888">
Andreas Neumann<br>
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Switzerland<br>
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