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 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.