upgrade the sos model to support several sensors per layer

[mapserver-bot]

Reporter: assefa
Date: 2007/03/22 - 16:18
Trac URL: http://trac.osgeo.org/mapserver/ticket/2050

In the current Mapserver SOS model, we have to specify 1 procedure (station) per
layer (using the sos_procedure metadata at the layer level). When the user wants
to use several stations, we eneded up duplication the layers with the procedure
being the only thing changing between layers 

The proposed change is to allow a use to specify a attribute from it's data that
can be ised as the procedure. Thus he could group into the same layer several
stations and the procedure could be extrcated from the data. 
To implement this the intention is to use an sos_procedure_item metadata.

[mapserver-bot]

Author: assefa
Date: 2007/05/17 - 23:06
Current support has been upgraded to use a new metadata called sos_procedure_item. The value for sos_procedure_item is the field name containing the procedure values The use of this metadata as well as the sos_procedure is described here per type of request:

1. GetCapabilities
   a. if sos_procedure is defined, use it
   a. if not look for sos_procedure_item : procedure values are extracted from the layer's attribute specified by this metadata. Not that this can be time consuming for layers with a large number of features.
   a. if none is defined return an exception
2. DescribeProcedure
   a. if sos_procedure is defined, use it
   a. if not look for sos_procedure_item : procedure values are extracted from the layer's attribute specified by this metadata. Not that this can be time consuming for layers with a large number of features.
   a. if none is defined return an exception
3. GetObservation
   Both sos_procedure and sos_procedure_item can be define. Here are the cases:
   a. if only sos_procedure is defined:
   i. Use this metadata to match the layer with the procedure value sent in the request
   i. When outputing the <member/procedure> output the value of the metadata
   a. if only procedure_item is defined:
   i. se the sos_procedure_item and do a query on the layer to match the procedure with the layer.
   i. When outputting the <member/procedure> use the procedure_item as a way to only output the attribute value corresponding to the feature.
   a. both are defined:
   i. check in sos_procedure to match the procedure with the layer.
   i. When outputting the <member/procedure> use the procedure_item as a way to only output the attribute value corresponding to the feature

[mapserver-bot]

Author: assefa
Date: 2007/05/18 - 00:19
Closed. Doc updated.