[OpenLayers-Dev] WMC on WMSManager

[Tim Schaub]

Hey Lorenzo-

Lorenzo Becchi wrote:
> Nothing to be proud of but I've published a first step to support Web 
> Map Context inside OpenLayers:
> 
> http://tinyurl.com/2b6z6r
> 

Looks like you've been busy.

A few ideas:

It would be good to start working towards a JavaScript structure for the 
map context.  For OL, this structure would contain all relevant layer 
information and the current map center/resolution.  On the WMC side, we 
should discuss how to standardize the extensions to WMC to account for 
OL specific stuff.

This structure should be serialized/deserialized with a JSON parser.
http://dev.openlayers.org/sandbox/tschaub/geojson/lib/OpenLayers/Format/JSON.js
(for example - and you can do format.write(obj, pretty) too)

In addition to translating this structure into a WMC doc, we should be 
able to translate it into a short string - though this will be lossy, it 
can be used to replace the permalink logic.

All this could be handled by a control like OpenLayers.Control.Context 
or OpenLayers.Control.ApplicationState.  This control would use the JSON 
format and a (yet to be built) WMC format.

I'll be working on this sort of stuff over the next couple months.  I 
look forward to collaborating.

Tim

> Click on the bottom-right button "WMC Exporter" to see a pop-up with the 
> JSON code of the WMC.
> Naturally you can alter the map with WMSManager and the WMC "should" be 
> updated.
> 
> as you can see:
> - the structure is not a perfect WMC. I've took a look from the 1.1 
> specs but there are things to be cleaned up.
> - some values are empty or null. Still have to decide if it make sense 
> to use all of them. We can decide together which optional elements not 
> to support.
> - I've added a "visibility" attribute to Layer object because WMC is not 
> providing it. Some hint how to avoid this? I'm sure you understand how 
> this is important for OL to define base or overlay layers.
> 
> as you can't see:
> - not all values are dinamically set. Some are still hardcoded.
> 
> 
> there's another problem about attributes of Layers with multiple WMS 
> layers inside. Which title, abstract to use? does it make sense to 
> create a comma (or something else) separated list of values?
> 
> 
> I'm still not sure if the MapContext should be part of the OL.Map object 
> or an external Tool.
> I'll go on with the external tool and hope to create soon a WMCParser to 
> import WMCs.
> 
> 
> My hope was to offer something better before leaving for holidays but 
> many meeting/debate/ecc at work delayed coding time.
> I'll leave in 2 days and be back for the third week of August. In the 
> meantime I'll be available for debate about this solution.
> 
> ciao
> Lorenzo
> 
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