/// <summary>
/// Extension method to use V3 to V4 translation middleware.
/// </summary>
/// <param name="builder">IApplicationBuilder that will use translation middleware</param>
/// <param name="v3model">V3 model that represents edmx contract</param>
/// <param name="v4Model">Required V4 model to validate translated URI</param>
/// <returns>builder now using migration middleware</returns>
public static IApplicationBuilder UseODataMigration(this IApplicationBuilder builder,
Data.Edm.IEdmModel v3model,
Microsoft.OData.Edm.IEdmModel v4Model)
{
// Convert v3 model to string to pass through metadata request.
string v3Edmx;
using (StringWriter stringWriter = new StringWriter())
{
using (XmlWriter xmlWriter = XmlWriter.Create(stringWriter))
{
IEnumerable <Data.Edm.Validation.EdmError> errors = new List <Data.Edm.Validation.EdmError>();
Data.Edm.Csdl.EdmxWriter.TryWriteEdmx(v3model, xmlWriter, Data.Edm.Csdl.EdmxTarget.OData, out errors);
}
v3Edmx = stringWriter.ToString();
}
return(builder.UseODataMigration(v3Edmx, v4Model));
}
/// <summary>
/// Constructs an instance of TranslationMiddleware, requiring the root of the service, a V3 model instance and V4 model instance.
/// </summary>
/// <param name="next">Delegate required for middleware</param>
/// <param name="v3Edmx">V3 EDMX string representation of model</param>
/// <param name="v4Model">Instance of V4 EDM model</param>
public ODataMigrationMiddleware(RequestDelegate next,
string v3Edmx,
Microsoft.OData.Edm.IEdmModel v4Model)
{
ExceptionUtil.IfArgumentNullThrowException(v3Edmx, "v3Edmx", "V3 edmx cannot be empty");
ExceptionUtil.IfArgumentNullThrowException(v4Model, "v4Model", "V4 model cannot be null");
this.next = next;
this.serviceRoot = new Uri("http://localhost/"); // The actual service root doesn't matter; it is just needed as a parameter
this.v4Model = v4Model;
try {
using (XmlReader reader = XmlReader.Create(new StringReader(v3Edmx)))
{
this.v3Model = Data.Edm.Csdl.EdmxReader.Parse(reader);
}
}
catch (Exception)
{
throw new ArgumentException("Unable to parse OData V3 Edmx; make sure your edmx is a valid OData contract.");
}
}