Changes between Initial Version and Version 1 of Maestro3CustomCommands

Timestamp:

07/07/10 06:24:42 (14 years ago)

Author:

jng

Comment:

--

Maestro3CustomCommands

@@ +1 @@
+= Custom Commands =
+
+== The problem ==
+
+The current ServerConnectionI interface is a monolithic interface. It is hard to add functionality that may not be possible on certain implementations. A flexible way to extend functionality is required.
+
+== The solution ==
+
+Taking a page out of the FDO API, we will use a command-based API for defining custom functionality
+
+{{{
+
+public interface ICommand
+{
+    ...
+    IServerConnection Parent { get; }
+}
+
+public interface IServerConnection
+{
+    ...
+ 
+    ICommand CreateCommand(int commandType);
+
+    ...
+}
+
+}}}
+
+A capability API will also be made available so that certain implementations can advertise what commands they support.
+
+Through this command mechanism, we can then define custom commands that certain implementations of IServerConnection may or may not choose to implement.
+
+For example, Bulk copying.
+
+{{{
+
+// Copies features from one feature source to another
+public interface IBulkCopy : ICommand
+{
+    string SourceFeatureSource { get; set; }
+
+    string TargetFeatureSource { get; set; }
+
+    void AddMapping(BulkCopyMapping mapping);
+
+    void Execute(IBulkCopyProgressCallback callback);
+}
+
+public class BulkCopyMapping
+{
+    public string SourceFeatureClass { get; set; }
+    public string TargetFeatureClass { get; set; }
+
+    ...
+}
+
+}}}
+
+Another example, re-projecting features
+
+{{{
+
+// Selects features from the specified feature class and re-projects them to the
+// target coordinate system.
+public interface IReprojectFeatures : ICommand
+{
+    public string SourceFeatureSource { get; set; }
+
+    public string SourceFeatureClass { get; set; }
+
+    public string Filter { get; set; }
+
+    public string SourceCoordinateSystem { get; set; }
+
+    public string TargetCoordinateSystem { get; set; }
+
+    public void Execute(IReprojectFeaturesCallback callback);
+}
+
+}}}
+
+These are just some examples off the top of my head, but a whole stack of geo-processing functionality could be made available through such an approach.