Features configuring OData service for GIS applications

Before use, you must download the project from github:

https://github.com/Flexberry/NewPlatform.Flexberry.ORM.GisPostgresDataService and https://github.com/Flexberry/NewPlatform.Flexberry.ORM.GisMSSQLDataService or to load assemblies from nuget.org NewPlatform.Flexberry.ORM.GisPostgresDataService and NewPlatform.Flexberry.ORM.GisMSSQLDataService.

After a successful compilation connect created Assembly to the project. Required also version ODataService not lower 2.0.1-alpha01. It can be downloaded from nuget.org NewPlatform.Flexberry.ORM.ODataService.

Need to modify the file Web.config by editing the appropriate string for MSSQL server:

<appSettings>
...
  <add key="DataServiceType" 
  value="NewPlatform.Flexberry.ORM.GisMSSQLDataService, NewPlatform.Flexberry.ORM.GisMSSQLDataService" />
...
</appSettings>

or for PostgreSQL server:

<appSettings>
...
  <add key="DataServiceType" 
  value="NewPlatform.Flexberry.ORM.GisPostgresDataService, NewPlatform.Flexberry.ORM.GisPostgresDataService" />
...
</appSettings>

data Types

MSSQL server

Field in the table to MSSQL server must be of type Geography

PostgreSQL server

A field in a table to PostgreSQL server should be of type Geography

.Net

Type properties the class inherits from DataObject should be Microsoft.Spatial.Geography

Use

In the request to the ODataService

Filtering data objects in option $filter query using a custom function geo.intersects(geography1=geo1, geography2=geo2) in OData, where “geo1” and “geo2” can be fields of data objects of type Edm.Geography and geographically referenced geometry specified in EWKT format, for example: geo.intersects(geography1=boundingBox, geography2=geography'SRID=<Code of the coordinate system used>;POLYGON(<coordinates of the polygon>)') where geography method to convert a string with coordinates in the format in EWKT type Edm.Geography.

Example query: http://localhost/odata/Classknotesaction?$filter=PropertyInt eq 5 and geo.intersects(geography1=PropertyGeography, geography2=geography'SRID=4326;POINT(3 3)').

In the request to LINQProvider

    Geography geo = "POINT(3 3)".CreateGeography();
    ViewAttribute gisView = new ViewAttribute("gisView", new string[] {
    "Name as \'Name\'",
    "Description as \'Description\'",
    "KeyWords as \'Keywords\'",
    "As the Lat \'Latitude\'",
    "Lng as \'Longitude\'",
    "Zoom as \'Zoom\'",
    "Public as \'General\'",
    "Scale as \'Scale\'",
    "CoordinateReferenceSystem as \'coordinate System is\'",
    "BoundingBox as \'the Border\'"});
    list = ds.Query<Map>(new View(gisView, typeof(Map))).Where(d => d.BoundingBox.GeoIntersects(geo)).ToList();

In the query using LCS

    var ldef = ExternalLangDef.LanguageDef;
    var lcs = LoadingCustomizationStruct.GetSimpleStruct(typeof (Map), new View(gisView, typeof (Map)));
    lcs.LimitFunction =
        ldef.GetFunction(ldef.funcGeoIntersects, new VariableDef(ldef.GeographyType, "BoundingBox"), geo);
    list = ds.LoadObjects(lcs);