[Qgis-developer] Run Feature Action Behaviour

[Giuseppe Sucameli]

Hi Haubourg,

On Mon, Jul 23, 2012 at 11:52 AM, haubourg
<regis.haubourg at eau-adour-garonne.fr> wrote:
>  - "Hotlink" tries to copy Mapinfo . Just pick the tool, fly over features
> and a tooltip appears filled with "display fields" of all underlying layers.
> Then click on a feature shows a listbox filled with action name + display
> field. Click on a line runs action

it seems to me that the way Hotlink runs actions is quite similar
to the Identify tool way:
first click on the map, than choose the action to run on one
feature.

The Run feature action way is exactly the opposite one:
first select the action, than clicking more times on the map
you can run it on more features.

The "added value" of the Hotlink is displaying tooltips, I guess.

>  - "Run Feature Action first requires to choose an active layer in TOC, then
> choose the action you want in toolbar (dropdown menu), then click to run
> action. If you want to know what feature is concerned, you need to activate
> tooltips. Last thing, Run Feature action does not seem compatible with old
> syntax of field expression (in 1.7.x %myfield, > 1.8 ["%myField Or
> myexpression%"]

Run feature action is in master since QGis 1.8, thus it uses the
new action syntax.

More in detail, the Run feature action tool itself doesn't know
anything about the syntax, expressions are just strings for it.
It's the actions evaluation that differs, it now uses the QGis
expression engine.

I broke the old behavior after asking on the dev ML [1], probably
if someone had replied to keeping it compatible than now you
wouldn't have this problem.

>   - Adds retrocompatibility for old syntax

not sure that is a good idea, there was the time for this kind of
request and now it's late, IMHO. But let's wait for other opinions.

>   - use the same behaviour as "identify" tool : active layer, first layer
> found , all layers. That would be more user friendly I guess.

I really do not understand how to run an action (which is defined on
a layer) on more/all the layers...

I still think the Hotlink plugin is quite similar to the identify tool:

1. Identify tool allows you to see full informations about the
features, i.e. all the attributes values and not the first one only
which usually is a non-significant number,
2. it open a non-modal window that you can move outside the
canvas and then click on the map more times without any needs
to close it,
3. you can choose the action to run on only one feature.

It's not clear to me why don't use the identify tool.
Have I missing something?

Regards.

[1] http://lists.osgeo.org/pipermail/qgis-developer/2012-January/017599.html

-- 
Giuseppe Sucameli