/// <summary>
/// Overrides the base HandleCloudQuery so that we can support a spatial search VisitWithinRadius.
/// </summary>
/// <param name="node"></param>
/// <param name="mappingState"></param>
/// <returns></returns>
protected override string HandleCloudQuery(QueryNode node, CloudQueryMapper.CloudQueryMapperState mappingState)
{
if (node.NodeType == QueryNodeType.Custom)
{
if (node is WithinRadiusNode)
{
return(this.VisitWithinRadius((WithinRadiusNode)node, mappingState));
}
}
return(base.HandleCloudQuery(node, mappingState));
}
/// <summary>
/// Provides a Geo Spatial Search Query linq provider.
/// </summary>
/// <param name="radiusNode"></param>
/// <param name="state"></param>
/// <returns></returns>
protected virtual string VisitWithinRadius(WithinRadiusNode radiusNode, CloudQueryMapper.CloudQueryMapperState state)
{
var orderBy = string.Empty;
if ((bool)radiusNode.DistanceSort)
{
orderBy = $"&$orderby=geo.distance({radiusNode.FieldName}, geography'POINT({radiusNode.Longitude} {radiusNode.Latitude})') asc";
}
var queryText = $"&search=*&$top={radiusNode.MaxResults}&$filter=geo.distance({radiusNode.FieldName}, geography'POINT({radiusNode.Longitude} {radiusNode.Latitude})') le {radiusNode.Radius}{orderBy}";
return(queryText);
}
