Hi,
Actually, I sent a mail to the maps mailing list already but there was
no feedback at all so I am taking Jeroens advice and try it again here,
there might be some users using maps and waiting for the image maps
feature. I already included some of the features suggested in my last
mail to "maps-l(a)lists.wikimedia.org" a little different though.
Recently I have been fixing the Maps extension openlayers image feature
to use images as maps again (the feature was broken around Maps 1.0).
Besides fixing the feature for the next version of maps, I have
implemented the following features already:
* Additional parameters on layer pages (unit, maxScale, minScale) to
better control how the map is being displayed.
* Markers can have a group, each group is represented as one overlay
layer and has its own marker colour (for default markers).
* the "display_..." functions/tags using a layer: page store this in the
database, layer-pages show which pages are using the layer and pages
using a layer will be purged when the layer changes.
* Database table for layers which should increase performance and allows
to define several layers in one page to group them. Using the layer page
name will include all of these group members into the base map-selection
of a map. Also, a <layer name="" type="">...properties...</layer> tag is
used to define layers now. Via 'name' the layer can have a name so a
specific group member layer can be used instead of the whole group of
layers defined on the same layer-page.
now I am writing because I am planing on implementing some more features
which I need some opinion on:
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1. I have implemented first attempts of allowing overlay maps. The
overlay feature introduces the attribute 'overlays' for 'display_map'
and 'display_point' like:
<display_map service="openlayers" layers="Moon Map" overlays="Moon
Station, Moon City">0,0</display_map>
where 'Moon Station' and 'Moon City' could be smaller maps located on
'Moon Map', simply images with more detail where you can zoom in from a
overall view of moon into a detail view of the base and the city. The
cool thing about this is, that overlay maps also could be displayed as
baselayers if you use them with the 'layers' parameter instead (since
they must have a layer: page anyway)
This works, but it doesn't make much sense without coordinates for the
overlays. So I am thinking about a appropriate syntax but can't come up
with anything nice:
<display_map service="openlayers" layers="Moon Map" overlays="Moon
Station|20;40, Moon City|100;40">0,0</display_map>
for example wouldn't be very consistent syntax compared to the other map
syntax and I don't even want to think about #display_points which has
some weird syntax compared to <display_points>
How about:
<display_map service="openlayers" layers="Moon Map" overlays="Moon
Station|Station, Moon City|City" addresses="Station (20,40), City
(100,40)">0,0</display_map>
So we would first declare some named addresses and assign them to
coordinates, from then on we can use the names for image layers just
like in mapping services like bing or google maps where you can just
write 'New York' instead of the actual geographical coordinates. And not
using the () within 'overlays' has the advantage that layer sites still
can contain '(' and ')' within the site name. It also allows to use the
addresses for markers like:
<display_points service="openlayers" layers="Moon Map" overlays="Moon
Station|Station, Moon City|City" addresses="Station (20,40), City (100,40)">
Station | Moon Station | This is the moon station | station.png | Group 1
</display_map>
So instead of using coordinates we can use names as coordinates for
markers within image layers as well!
This goes even one step further with the following...
2. ...allowing to define addresses within the layer page. This could be
a parameter 'addresses' which contains coordinates and names of
addresses which can be used for overlays and markers for 'display_point'
and for overlays using 'display_map'.
This could look like:
<layer type="image">
source = moon.jpg
...
addresses = station (20,40), city (100,40), ....
</layer>
addresses would be case-insensitive and would even make the use of the
'addresses' parameter within the display functions obsolete when using
overlays but the main advantage would of course be that markers can be
added very fast and without searching for coordinates first since all
important coordinates are described already.
'addresses' parameter of display functions will overwrite if one name is
given there and on a layer page.
3. its difficult with units. Layers can have different units like
degree, km, miles... I didn't look into how it works if markers with
units are defined in display_marker if there are layers with different
units. Perhaps we should allow coordinates with units like "20km,200m"
to make it clear. This could also be included in layer pages so we can
say "left-extend=20km" and stuff like that instead of having a "unit"
attribute.
There might me more simple solutions though, have not really looked into
that yet.
4. Since the custom layer features will require database support and
update now, we are thinking about making it as a separate extension for
Maps extension like SemanticMaps. Would be some work to separate all the
stuff though so I am also thinking about simply disabling the layers
functionality in case no database update was run yet - without throwing
any php errors.
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Any thoughts on that?
If you have any further ideas for the image layer feature, please write
a separate mail instead of answering to this one, except it is highly
related to one of the points above! Thanks!
Cheers,
Daniel