/// <summary>
/// Creates the WFS XML string that can be used in a HTTP Post request.
/// </summary>
/// <param name="requestUrl">The request URL.</param>
/// <param name="boundingBox">The bounding box.</param>
/// <returns>A string containing WFS XML-text.</returns>
private static string CreateWfsGetFeatureXmlString(string requestUrl, WfsBoundingBox boundingBox)
{
NameValueCollection nameValueCollection;
StringBuilder sb;
const string getFeatureStart = "<wfs:GetFeature xmlns:wfs=\"http://www.opengis.net/wfs\" service=\"WFS\" version=\"[Version]\" outputFormat=\"[OutputFormat]\" xsi:schemaLocation=\"http://www.opengis.net/wfs http://schemas.opengis.net/wfs/1.1.0/wfs.xsd\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\">";
const string getFeatureEnd = "</wfs:GetFeature>";
const string queryStart = "<wfs:Query typeName=\"[TypeName]\" srsName=\"[SrsName]\">";
const string queryEnd = "</wfs:Query>";
nameValueCollection = HttpUtility.ParseQueryString(requestUrl);
string version = nameValueCollection["version"];
string typeName = nameValueCollection["typename"];
string srsName = nameValueCollection["srsName"];
string filter = nameValueCollection["filter"];
// Get geometry name
WFSDescribeFeatureType describeFeatureType = GetWFSDescribeFeatureType(requestUrl, typeName);
string geometryName = describeFeatureType.GeometryField.Name;
string strFilterXml = CreateWfsXmlFilterString(filter, geometryName, boundingBox);
sb = new StringBuilder();
sb.Append(getFeatureStart.Replace("[Version]", version).Replace("[OutputFormat]", "json"));
sb.Append(queryStart.Replace("[TypeName]", typeName).Replace("[SrsName]", srsName));
sb.Append(strFilterXml);
sb.Append(queryEnd);
sb.Append(getFeatureEnd);
string str = sb.ToString();
return(str);
}
/// <summary>
/// Gets the WFS features using a HTTP Post request.
/// </summary>
/// <param name="requestUrl">The request URL.</param>
public static FeatureCollection GetWfsFeaturesUsingHttpPost(string requestUrl)
{
WfsBoundingBox boundingBox = null;
NameValueCollection nameValueCollection = HttpUtility.ParseQueryString(requestUrl);
// try parse bounding box
string srsName = nameValueCollection["srsName"];
string strBBox = nameValueCollection["bbox"];
if (!string.IsNullOrEmpty(strBBox) && !string.IsNullOrEmpty(srsName))
{
string[] bboxItems = strBBox.Split(',');
if (bboxItems.Length == 4)
{
double minX, minY, maxX, maxY;
if (double.TryParse(bboxItems[0], NumberStyles.Number, CultureInfo.InvariantCulture, out minX) && double.TryParse(bboxItems[1], NumberStyles.Number, CultureInfo.InvariantCulture, out minY) &&
double.TryParse(bboxItems[2], NumberStyles.Number, CultureInfo.InvariantCulture, out maxX) && double.TryParse(bboxItems[3], NumberStyles.Number, CultureInfo.InvariantCulture, out maxY))
{
boundingBox = new WfsBoundingBox(minX, minY, maxX, maxY, srsName);
}
}
}
return(GetWfsFeaturesUsingHttpPost(requestUrl, boundingBox));
}
/// <summary>
/// Creates a WFS XML filter string.
/// </summary>
/// <param name="filter">The filter string.</param>
/// <param name="geometryName">Name of the geometry object.</param>
/// <param name="boundingBox">The bounding box.</param>
/// <returns>A string containing WFS XML-text.</returns>
private static string CreateWfsXmlFilterString(string filter, string geometryName, WfsBoundingBox boundingBox)
{
FormulaOperation formulaOperation;
SpatialOperation bboxOperation = null;
if (string.IsNullOrEmpty(geometryName))
{
geometryName = "the_geom";
}
if (boundingBox != null)
{
SpatialBoundingBox spatialBoundingBox = new SpatialBoundingBox(boundingBox.MinX, boundingBox.MinY, boundingBox.MaxX, boundingBox.MaxY, boundingBox.SrsName);
bboxOperation = new SpatialOperation(new SpatialFieldValue(geometryName), spatialBoundingBox, WFSSpatialOperator.InsideBbox);
}
if (string.IsNullOrEmpty(filter))
{
formulaOperation = bboxOperation ?? null;
}
else
{
WfsFormulaParser parser = new WfsFormulaParser();
formulaOperation = parser.Parse(filter);
if (bboxOperation != null)
{
formulaOperation = new BinaryLogicalOperation(formulaOperation, bboxOperation, WFSBinaryLogicalOperator.And);
}
}
WFSFilter wfsFilter = new WFSFilter {
Formula = formulaOperation
};
string strWfsXmlRepresentation = wfsFilter.WfsXmlRepresentation();
return(strWfsXmlRepresentation);
}
/// <summary>
/// Gets the WFS features using a HTTP Post request.
/// </summary>
/// <param name="requestUrl">The request URL.</param>
/// <param name="boundingBox">The bounding box.</param>
public static FeatureCollection GetWfsFeaturesUsingHttpPost(string requestUrl, WfsBoundingBox boundingBox)
{
var uri = new Uri(requestUrl);
string baseUrl = uri.GetLeftPart(UriPartial.Path);
string postData = CreateWfsGetFeatureXmlString(requestUrl, boundingBox);
string strJson = MakeHttpPostRequest(baseUrl, postData);
// Make a Json string to a featue collection type
FeatureCollection featureCollection = JsonConvert.DeserializeObject(strJson, typeof(FeatureCollection)) as FeatureCollection;
return(featureCollection);
}
