Changes between Initial Version and Version 1 of maestro/MaestroAPI/samples/QueryFeatureSource

Timestamp:

Jan 15, 2010, 12:38:11 AM (14 years ago)

Author:

ksgeograf

Comment:

--

maestro/MaestroAPI/samples/QueryFeatureSource

@@ +1 @@
+
+== Query Features with a filter ==
+This page describes how to use the MaestroAPI from the [wiki:maestro MapGuide Maestro] project in your own application.
+
+This sample shows how to read geometry features from a !FeatureSource using MaestroAPI.
+
+(C#)
+{{{
+using OSGeo.MapGuide.MaestroAPI;
+...
+
+//Read the setup, either from QueryString, Form, Cookies or hardcoded values
+string username = Request.Params("USERNAME") == null ? "Anonymous" : Request.Params("USERNAME");
+string password = Request.Params("PASSWORD") == null ? "" : Request.Params("PASSWORD");
+string layout = Request.Params("LAYOUT") == null ? "Library://MyLayout.WebLayout" : Request.Params("LAYOUT");
+string locale = Request.Params("LOCALE") == null ? "en" : Request.Params("LOCALE");
+string sessionid = Request.Params("SESSION");
+
+
+//Variables that should be replaced
+string serverUrl = "http://localhost/mapguide/mapagent/mapagent.fcgi";
+string featureSourceId = "Library://my data source.FeatureSource";
+string classname = "Default:Test";
+string filter = "ID = 5 AND Y LIKE 'test*'";
+
+//Setup connection
+Uri host = new Uri(serverUrl);
+ServerConnectionI con;
+
+//Either use session id or explicit credentials
+if (string.IsNullOrEmpty(sessionid))
+    con = new HttpServerConnection(host, username , password, locale, true);
+else
+    con = new HttpServerConnection(host, sessionid, true);
+
+//Get the featuresource
+FeatureSource fs = con.GetFeatureSource(featureSourceId);
+FeatureSourceDescription desc = fs.DescribeSource(classname);
+
+//Find the geometry column
+FeatureSetColumn geometryColumn = null;
+foreach(FeatureSetColumn col in desc.Schemas[0].Columns)
+    if (col.Type == MaestroAPI.Utility.GeometryType)
+        geometryColumn = col; //TODO: If there are more than one?
+
+//Add any extra columns that you need
+string[] columns = new string[] { geometryColumn.Name };
+
+//Prepare a list
+List<Topology.IO.Geometry.IGeometry> features = new List<Topology.IO.Geometry.IGeometry>();
+
+//Execute the query
+using (FeatureSetReader rd = fs.SelectFeatures(classname, filter, columns))
+    while (rd.Read())
+        features.Add(rd.Row[geometryColumn.Name] as Topology.IO.Geometry.IGeometry);
+
+//The list "features" is now a list of all geometry found by applying the filter.
+}}}
+
+