/// <summary>
/// Downloads records and yields them as a lazy sequence of features of the specified type. Possibly throws RestException.
/// </summary>
/// <typeparam name="T">The type the record should be mapped to.</typeparam>
/// <param name="layerId">The layer ID of the feature layer or table.</param>
/// <param name="whereClause">The where clause. If set to null, returns all features.</param>
/// <param name="geometry">The geometry used to spatially filter the records.</param>
/// <param name="spatialRel">The spatial relationship used for filtering.</param>
/// <param name="extraParameters">The query string that describes any additional query parameters (i.e. outSR=4326). Each parameter must be url encoded.</param>
/// <param name="keepQuerying">If set to true, repetitively queries the server until all features have been returned.</param>
/// <param name="degreeOfParallelism">The maximum number of concurrent requests.</param>
/// <returns></returns>
public IEnumerable <T> Download <T>(int layerId, string whereClause, GeometryBase geometry, SpatialRel spatialRel, string extraParameters = null, bool keepQuerying = false, int degreeOfParallelism = 1) where T : Feature
{
if (geometry == null)
{
return(Download <T>(layerId, whereClause, extraParameters, keepQuerying, degreeOfParallelism));
}
string geometryType;
if (geometry is Point)
{
geometryType = "esriGeometryPoint";
}
else if (geometry is Multipoint)
{
geometryType = "esriGeometryMultipoint";
}
else if (geometry is Polyline)
{
geometryType = "esriGeometryPolyline";
}
else if (geometry is Polygon)
{
geometryType = "esriGeometryPolygon";
}
else if (geometry is Envelope)
{
geometryType = "esriGeometryEnvelope";
}
else
{
throw new ArgumentException("This geometry type is not supported.", nameof(geometry));
}
var spatialFilter = $"geometry={Compatibility.UrlEncode(geometry.ToString())}&geometryType={geometryType}&spatialRel=esriSpatialRel{spatialRel}";
return(Download <T>(layerId, whereClause, string.IsNullOrEmpty(extraParameters) ? spatialFilter : (extraParameters + "&" + spatialFilter), keepQuerying, degreeOfParallelism));
}
/// <summary>
/// Returns the JSON representation of the geometry.
/// </summary>
/// <param name="geometry"></param>
/// <returns></returns>
public static string ToJson(this GeometryBase geometry)
{
return(geometry?.ToString());
}