Custom Data service providers-(5) Minimal runtime Service

For the complete tutorial directory, see :《CustomData service providers-Introduction"

 

 

In the previous tutorial, we have implementedIserviceproviderAndIdataservicemetadataprovider, Now let's continue.

Mount Idataservicequeryprovider Implementation

Now we plan to implementIdataservicequeryproviderInterface, We Need To refactor the previously implementedIserviceproviderInterface.

Public abstract class dspdataservice <t>:

Dataservice <t>, iserviceprovider

{

Public idataservicemetadataprovider _ metadata;

Public idataservicequeryprovider _ query;

 

Public dspdataservice ()

{

_ Metadata = getmetadataprovider (typeof (t ));

_ Query = getqueryprovider (_ metadata );

}

Public object getservice (type servicetype)

{

If (servicetype = typeof (idataservicemetadataprovider ))

Return _ metadata;

Else if (servicetype = typeof (idataservicequeryprovider ))

Return _ query;

Else

Return NULL;

}

 

Public abstract idataservicemetadataprovider

Getmetadataprovider (type datasourcetype );

 

Public abstract idataservicequeryprovider

Getqueryprovider (idataservicemetadataprovider metadata );

}

Note: You need to implement it in your own implementation class.GetqueryproviderMethod.

IdataservicequeryproverImplementation may requireIdataservicemetadataproviderSo this parameter is passed in.

Public class sample: dspdataservice <Object>

{

...SeeCode...

 

Public override idataservicequeryprovider

Getqueryprovider (idataservicemetadataprovider metadata)

{

Return new dspqueryprovider <Object> ();

}

}

Implementation Idataservicequeryprovider

If you only want to see the service contract and$ MetadataInformation, then implementCurrentdatasourceAttribute. Other methods of this interface are returned after the query is called.Resourcesets.

Public class dspqueryprovider <t>: idataservicequeryprovider

{

T_currentdatasource;

Public object currentdatasource

{

Get {

Return _ currentdatasource;

}

Set {

_ Currentdatasource = value as t;

}

}

Public object getopenpropertyvalue (

Object target,

 String propertyname)

{

Throw new notimplementedexception ();

}

Public ienumerable <keyvaluepair <string, Object>

Getopenpropertyvalues (object target)

{

Throw new notimplementedexception ();

}

Public object getpropertyvalue (

Object target,

Resourceproperty)

{

Throw new notimplementedexception ();

}

Public iqueryable getqueryrootforresourceset (

Resourceset)

{

Throw new notimplementedexception ();

}

Public resourcetype getresourcetype (object target)

{

Throw new notimplementedexception ();

}

Public object invokeserviceoperation (

Serviceoperation,

Object [] parameters)

{

Throw new notimplementedexception ();

}

Public bool isnullpropagationrequired

{

Get {Throw new notimplementedexception ();}

}

}

 

Well, at least our custom data service provider can now run, although it can only provide metadata information.

In the browser, type:Http: // localhost/sample. SVCNow you can see the following picture:

Note: InVisual StudioIn the debugging environment,LocalhostA dynamic port is required later)

 

If you typeHttp: // localhost/sample. svc/$ metadataYou should see the following picture:

 

Of course, we have not implemented the query. If you want to navigateProductsIf the resource set is used, an error is returned (the address is:Http: // localhost/sample. svc/products