[OpenLayers-Users] Http request?

[Andrea Maschio]

Il giorno 18/gen/08, alle ore 13:02, Christopher Schmidt ha scritto:
>
> The "X" in AJAX is for XML/XMLHttpRequest. XMLHttpRequest is not
> neccesary to receive tiles -- instead, the proper URL is simply stuck
> into an <img> tag, which (of course) can be loaded from other sites.

Ok, so as I understand except fo wfs-t (that means transactional web  
feature service and it's supposed to edit geometries and for this to  
interact with the server) all other types of OL visualizations are  
based on an image that is generated by the application server and  
provided with layer information and other useful visualization stuff  
in the xml file generated.

Sorry if it is obvious, but i'm trying to figure out what i need and  
if OL covers my purposes. Because I need to select some feature and  
then with the information collected by a selection (with the mouse)  
dialog with the server to do some operation on data.

Do I need wfs-t for this or maybe is better to collect the data in non  
httprequest-way and then treat the data as parameters for a query. I  
mean: in wfs-t is there a simpler way to edit data than collecting all  
the gids of the features and then building a query with these ids?

> OpenLayers takes as a core tenet: "You can not talk to the server."  
> This
> means you can't use XMLHttpRequest to do anything that is crucial to
> functionality unless there is no other way. All configuration, for
> example, is not taken from the WMS GetCapabilities, but is instead  
> taken
> from local Javascript configuration -- duplicating information, but an
> unfortunate consequence of the Same Origin Policy.

Probably I didn't understood how things go in OL. When I instantiate a  
map and then a layer and then add a layer to the map, how goes the  
communication with the WFS server?

Please forgive me if I'm asking all these basic information. I'm  
checking out the docs, and I'm asking this because the architectural  
aspects are far from clear to me now.

Thanks a lot for helping

Andrea Maschio
http://www.superandrew.it