= !MapGuide RFC 105 - Enhance feature service !GetCapabilities API =

This page contains a change request (RFC) for the !MapGuide Open Source project.  
More !MapGuide RFCs can be found on the [wiki:MapGuideRfcs RFCs] page.


== Status == 
 
||RFC Template Version||(1.0)|| 
||Submission Date||July 20, 2010||
||Last Modified||Bruce Dechant July 27, 2010||
||Author||Bruce Dechant||
||RFC Status||adopted||
||Implementation Status||implemented||
||Proposed Milestone||2.3||
||Assigned PSC guide(s)||Bruce Dechant||
||'''Voting History'''||||
||+1||Bob, Bruce, Haris, Jackie, Jason, Paul, Tom, Trevor, Zac||
||+0||||
||-0||||
||-1||||
||Abstained||||
 
== Overview ==

This RFC proposes to add a NEW !GetCapabilites() API to the feature service which contains an additional connection string parameter. This new method should only be used to get connection-based capabilities on WFS and WMS providers until FDO specifies how connection-based connections should behave; use on any other providers may cause compatibility problems in the future.

== Motivation ==

The existing Feature service !GetCapabilties() API works correctly for most providers, but fails to return the true capabilities of the server connected to by a WFS/WMS provider because there is no way to specify the connection string containing the server.

Here is a subset of the WFS capabilities showing the differences.

WFS provider returned capabilites (existing API):
{{{
<Filter>
  <SupportsGeodesicDistance>false</SupportsGeodesicDistance> 
  <SupportsNonLiteralGeometricOperations>true</SupportsNonLiteralGeometricOperations> 
</Filter>
}}}

WFS provider returned capabilites (NEW API with server specified in connection string):
{{{
<Filter>
  <Condition>
    <Type>Comparison</Type> 
    <Type>Like</Type> 
    <Type>Spatial</Type> 
  </Condition>
  <Spatial>
    <Operation>EnvelopeIntersects</Operation> 
    <Operation>Intersects</Operation> 
  </Spatial>
  <SupportsGeodesicDistance>false</SupportsGeodesicDistance> 
  <SupportsNonLiteralGeometricOperations>true</SupportsNonLiteralGeometricOperations> 
</Filter>
}}}

== Proposed Solution ==

Create a NEW !GetCapabilities() API that takes an additional connection string parameter.

Existing API: (This will not change)
{{{
    MgByteReader* GetCapabilities(CREFSTRING providerName);
}}} 

Proposed NEW API:
{{{
    MgByteReader* GetCapabilities(CREFSTRING providerName, CREFSTRING connectionString);
}}} 

Note: This NEW API will behave exactly the same as the old API if it is given an empty string as the connection string parameter.

== Implications ==

This change will NOT break existing API compatibility.

== Test Plan ==

!Build/Run on !Windows/Linux.

== !Funding/Resources ==

Supplied by Autodesk.