[PPT] - WCF-2 Radu Nicolescu Department of Computer Science University of PowerPoint Presentation

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HelloWorld PingPong DataEF DataAD

WCF-2

Radu Nicolescu Department of Computer Science University of Auckland 21 Sept 2018

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HelloWorld PingPong DataEF DataAD

1 WCF Hello World 2 WCF Ping Pong 3 WCF Data Service EF 4 WCF Data Service A#4R Demo

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HelloWorld PingPong DataEF DataAD

Outline

1 WCF Hello World 2 WCF Ping Pong 3 WCF Data Service EF 4 WCF Data Service A#4R Demo

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HelloWorld PingPong DataEF DataAD

Declarative Web Interface – Attributes

Auto: ”Wire” (URLs) ⇔ Method invocations

1 [ S e r v i c e C o n t r a c t ( ) ] 2 public interface I H e l l o W o r l d S e r v i c e { 3 [ OperationContract ( IsOneWay=true ) ] 4 [ WebGet ( ) ] 5 void Hello ( string name ) ; 6 7 [ OperationContract ( ) ] 8 [ WebGet( ResponseFormat=WebMessageFormat . Json ) ] 9 string SayHello ( string name ) ; 10 }

Read more: see links in the code samples, ...

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HelloWorld PingPong DataEF DataAD

Declarative Web Interface – Attributes

[X]: auto-generated instance of XAttribute class
ServiceContractAttribute : ”Wire” interface
OperationContractAttribute: ”Wire” method
IsOneWay=true: property of OperationContractAttribute
indicates no response
WebGetAttribute: specific ”Wire” format: HTTP REST
ResponseFormat=WebMessageFormat.Json: property of

WebGetAttribute

selects JSON format (vs XML)

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HelloWorld PingPong DataEF DataAD

Declarative Web Interface – Attributes

[X]: auto-generated instance of XAttribute class
ServiceContractAttribute : ”Wire” interface
OperationContractAttribute: ”Wire” method
IsOneWay=true: property of OperationContractAttribute
indicates no response
WebGetAttribute: specific ”Wire” format: HTTP REST
ResponseFormat=WebMessageFormat.Json: property of

WebGetAttribute

selects JSON format (vs XML)

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HelloWorld PingPong DataEF DataAD

Declarative Web Interface – Attributes

[X]: auto-generated instance of XAttribute class
ServiceContractAttribute : ”Wire” interface
OperationContractAttribute: ”Wire” method
IsOneWay=true: property of OperationContractAttribute
indicates no response
WebGetAttribute: specific ”Wire” format: HTTP REST
ResponseFormat=WebMessageFormat.Json: property of

WebGetAttribute

selects JSON format (vs XML)

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HelloWorld PingPong DataEF DataAD

Server side implementation

Service implementation of the service contract

1 [ S e r v i c e B e h a v i o r ( 2 InstanceContextMode=InstanceContextMode . Single , 3 ConcurrencyMode=ConcurrencyMode . M u l t i p l e ) ] 4 5 public class HelloWorldService : 6 I H e l l o W o r l d S e r v i c e { 7 public void Hello ( string name) { 8 . . . ; 9 // no return: one way 10 } 11 12 public string SayHello ( string name) { 13 . . . ; 14 return $” Hello , {name}” ; 15 } 16 }

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HelloWorld PingPong DataEF DataAD

Server side implementation

ServiceBehaviorAttribute : specifies the internal execution

behavior of a service contract implementation

property InstanceContextMode=InstanceContextMode.Single
indicates one single instance, automatically created
property ConcurrencyMode=ConcurrencyMode.Multiple
indicates automatic multi-threading (CAVEAT: potential race

conditions!)

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HelloWorld PingPong DataEF DataAD

Server side implementation

ServiceBehaviorAttribute : specifies the internal execution

behavior of a service contract implementation

property InstanceContextMode=InstanceContextMode.Single
indicates one single instance, automatically created
property ConcurrencyMode=ConcurrencyMode.Multiple
indicates automatic multi-threading (CAVEAT: potential race

conditions!)

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HelloWorld PingPong DataEF DataAD

Server side implementation

ServiceBehaviorAttribute : specifies the internal execution

behavior of a service contract implementation

property InstanceContextMode=InstanceContextMode.Single
indicates one single instance, automatically created
property ConcurrencyMode=ConcurrencyMode.Multiple
indicates automatic multi-threading (CAVEAT: potential race

conditions!)

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HelloWorld PingPong DataEF DataAD

Server side hosting

External host: IIS, IISExpress, ...
Self-hosted (sketch)

1 Uri baseAddress = 2 new Uri ( ” http :// l o c a l h o s t :8081/ h e l l o ” ) ; 3 4 WebServiceHost host = 5 new WebServiceHost ( 6 typeof ( HelloWorldService ) , baseAddress ) ; 7 8 ServiceEndpoint ep = 9 host . AddServiceEndpoint ( 10 typeof ( I H e l l o W o r l d S e r v i c e ) , 11 new WebHttpBinding () , ”” ) ; 12 13 host . Open ( ) ;

Service endpoint: actual access to the service functionality

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HelloWorld PingPong DataEF DataAD

Server side hosting

External host: IIS, IISExpress, ...
Self-hosted (sketch)

1 Uri baseAddress = 2 new Uri ( ” http :// l o c a l h o s t :8081/ h e l l o ” ) ; 3 4 WebServiceHost host = 5 new WebServiceHost ( 6 typeof ( HelloWorldService ) , baseAddress ) ; 7 8 ServiceEndpoint ep = 9 host . AddServiceEndpoint ( 10 typeof ( I H e l l o W o r l d S e r v i c e ) , 11 new WebHttpBinding () , ”” ) ; 12 13 host . Open ( ) ;

Service endpoint: actual access to the service functionality

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HelloWorld PingPong DataEF DataAD

Server side hosting

External host: IIS, IISExpress, ...
Self-hosted (sketch)

1 Uri baseAddress = 2 new Uri ( ” http :// l o c a l h o s t :8081/ h e l l o ” ) ; 3 4 WebServiceHost host = 5 new WebServiceHost ( 6 typeof ( HelloWorldService ) , baseAddress ) ; 7 8 ServiceEndpoint ep = 9 host . AddServiceEndpoint ( 10 typeof ( I H e l l o W o r l d S e r v i c e ) , 11 new WebHttpBinding () , ”” ) ; 12 13 host . Open ( ) ;

Service endpoint: actual access to the service functionality

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HelloWorld PingPong DataEF DataAD

Server side hosting

Further
How to terminate the service
How to dispose of used system resources
How to deal with errors/exceptions

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HelloWorld PingPong DataEF DataAD

Client side

Using the same interface, if available
Using a reconstructed interface, from the service metadata

endpoint

Tools, wizards: VS, Linqpad, SvcUtil.exe, ...
Using URLs directly

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HelloWorld PingPong DataEF DataAD

Testing

Additional service methods, to also test service behaviour

(multi-threading)

1 public s t a t i c Func<int> Tid = 2 () = > Thread . CurrentThread . ManagedThreadId ; 3 4 public s t a t i c Func<double> M i l l i s = 5 () = > DateTime .Now. TimeOfDay . T o t a l M i l l i s e c o n d s ;

Tid: Thread ID
Milliseconds since start of the day

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HelloWorld PingPong DataEF DataAD

Testing

Sample output for several concurrent clients

1 . . . 2 [ 5 ] [46800192.5668] SayHello r e c e i v e d : mano6 3 [ 3 ] [46800195.5665] Hello r e c e i v e d : xinfeng1 4 [ 8 ] [46800204.5683] Hello r e c e i v e d : xinfeng2 5 [ 3 ] [46800208.5662] Hello r e c e i v e d : xinfeng3 6 [ 8 ] [46800209.5664] SayHello r e c e i v e d : mano7 7 [ 3 ] [46800209.5664] SayHello r e c e i v e d : xinfeng1 8 [ 8 ] [46800272.564] Hello r e c e i v e d : xinfeng5 9 . . .

First column: Thread ID
Second columns: Milliseconds since start of the day

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HelloWorld PingPong DataEF DataAD

Outline

1 WCF Hello World 2 WCF Ping Pong 3 WCF Data Service EF 4 WCF Data Service A#4R Demo

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HelloWorld PingPong DataEF DataAD

Ping Pong Interfaces

Two nodes, mutual client/servers, that exchange one-way

Ping/Pong messages

1 [ S e r v i c e C o n t r a c t ( ) ] 2 public interface I P i n g S e r v i c e { 3 [ OperationContract ( IsOneWay=true ) ] 4 [ WebGet ( ) ] 5 void Ping ( int t t l ) ; 6 } 7 [ S e r v i c e C o n t r a c t ( ) ] 8 public interface IPongService { 9 [ OperationContract ( IsOneWay=true ) ] 10 [ WebGet ( ) ] 11 void Pong ( int t t l ) ; 12 }

Ttl: time to live = number of hops before the message

exchange stops

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HelloWorld PingPong DataEF DataAD

Outline

1 WCF Hello World 2 WCF Ping Pong 3 WCF Data Service EF 4 WCF Data Service A#4R Demo

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HelloWorld PingPong DataEF DataAD

Data Service EF

Specialised API for exposing Entity Model objects (tables,

associations) over HTTP REST OData

Simple scenario: (almost) all code auto-generated (VS)

1 namespace WebApplication1 { 2 public class WcfDataService1 : 3 EntityFrameworkDataService <NorthwindEntities > { 4 public s t a t i c void I n i t i a l i z e S e r v i c e ( 5 D a t a S e r v i c e C o n f i g u r a t i o n c o n f i g ) { 6 c o n f i g . SetEntitySetAccessRule ( ”∗” , 7 E n t i t y S e t R i g h t s . AllRead ) ; 8 c o n f i g . DataServiceBehavior . MaxProtocolVersion = 9 DataServiceProtocolVersion . V3 ; 10 c o n f i g . UseVerboseErrors = true ; 11 } 12 } 13 }

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HelloWorld PingPong DataEF DataAD

Data Service EF models

NorthwindEntities: auto-generated model for the Northwind

database (selected objects)

Model1.Context.cs: database model
Customer.cs, Order.cs: C# classes for tables Customers,

Orders metadata

Model1.csdl, Model1.ssdl, Model1.msl: conceptual models,

storage models, mappings

SetEntitySetAccessRule(”∗”, EntitySetRights .AllRead): allow

read-access to all model items (here Customers and Orders)

MaxProtocolVersion: protocol version (we use the more

common V3)

UseVerboseErrors = true: to get more detailed error message
n the returned HTML page (own addition)

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HelloWorld PingPong DataEF DataAD

Data Service EF models

NorthwindEntities: auto-generated model for the Northwind

database (selected objects)

Model1.Context.cs: database model
Customer.cs, Order.cs: C# classes for tables Customers,

Orders metadata

Model1.csdl, Model1.ssdl, Model1.msl: conceptual models,

storage models, mappings

SetEntitySetAccessRule(”∗”, EntitySetRights .AllRead): allow

read-access to all model items (here Customers and Orders)

MaxProtocolVersion: protocol version (we use the more

common V3)

UseVerboseErrors = true: to get more detailed error message
n the returned HTML page (own addition)

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HelloWorld PingPong DataEF DataAD

Data Service EF models

NorthwindEntities: auto-generated model for the Northwind

database (selected objects)

Model1.Context.cs: database model
Customer.cs, Order.cs: C# classes for tables Customers,

Orders metadata

Model1.csdl, Model1.ssdl, Model1.msl: conceptual models,

storage models, mappings

SetEntitySetAccessRule(”∗”, EntitySetRights .AllRead): allow

read-access to all model items (here Customers and Orders)

MaxProtocolVersion: protocol version (we use the more

common V3)

UseVerboseErrors = true: to get more detailed error message
n the returned HTML page (own addition)

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HelloWorld PingPong DataEF DataAD

Data Service EF models

NorthwindEntities: auto-generated model for the Northwind

database (selected objects)

Model1.Context.cs: database model
Customer.cs, Order.cs: C# classes for tables Customers,

Orders metadata

Model1.csdl, Model1.ssdl, Model1.msl: conceptual models,

storage models, mappings

SetEntitySetAccessRule(”∗”, EntitySetRights .AllRead): allow

read-access to all model items (here Customers and Orders)

MaxProtocolVersion: protocol version (we use the more

common V3)

UseVerboseErrors = true: to get more detailed error message
n the returned HTML page (own addition)

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HelloWorld PingPong DataEF DataAD

Data Service EF – how does it work

The service is hosted under IISExpress ⇒ base URL

http://localhost:8181/

An HTTP GET request arrives at the base service URL

http://localhost:8181/WcfDataService1.svc/...

WcfDataService1.svc is a text file, indicating a namespace and

a class name, that will actually offer the service

1 . . . S e r v i c e=” WebApplication1 . WcfDataService1 ”

The runtime looks for this class through the bin DLLs ...
Summary: URL ⇒ SQL SELECT ...

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HelloWorld PingPong DataEF DataAD

Data Service EF – how does it work

The service is hosted under IISExpress ⇒ base URL

http://localhost:8181/

An HTTP GET request arrives at the base service URL

http://localhost:8181/WcfDataService1.svc/...

WcfDataService1.svc is a text file, indicating a namespace and

a class name, that will actually offer the service

1 . . . S e r v i c e=” WebApplication1 . WcfDataService1 ”

The runtime looks for this class through the bin DLLs ...
Summary: URL ⇒ SQL SELECT ...

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HelloWorld PingPong DataEF DataAD

Data Service EF – how does it work

The service is hosted under IISExpress ⇒ base URL

http://localhost:8181/

An HTTP GET request arrives at the base service URL

http://localhost:8181/WcfDataService1.svc/...

WcfDataService1.svc is a text file, indicating a namespace and

a class name, that will actually offer the service

1 . . . S e r v i c e=” WebApplication1 . WcfDataService1 ”

The runtime looks for this class through the bin DLLs ...
Summary: URL ⇒ SQL SELECT ...

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HelloWorld PingPong DataEF DataAD

Data Service EF – how does it work

The service is hosted under IISExpress ⇒ base URL

http://localhost:8181/

An HTTP GET request arrives at the base service URL

http://localhost:8181/WcfDataService1.svc/...

WcfDataService1.svc is a text file, indicating a namespace and

a class name, that will actually offer the service

1 . . . S e r v i c e=” WebApplication1 . WcfDataService1 ”

The runtime looks for this class through the bin DLLs ...
Summary: URL ⇒ SQL SELECT ...

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HelloWorld PingPong DataEF DataAD

Data Service EF – how does it work

The service is hosted under IISExpress ⇒ base URL

http://localhost:8181/

An HTTP GET request arrives at the base service URL

http://localhost:8181/WcfDataService1.svc/...

WcfDataService1.svc is a text file, indicating a namespace and

a class name, that will actually offer the service

1 . . . S e r v i c e=” WebApplication1 . WcfDataService1 ”

The runtime looks for this class through the bin DLLs ...
Summary: URL ⇒ SQL SELECT ...

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SLIDE 32

HelloWorld PingPong DataEF DataAD

Outline

1 WCF Hello World 2 WCF Ping Pong 3 WCF Data Service EF 4 WCF Data Service A#4R Demo

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HelloWorld PingPong DataEF DataAD

Data Service A#4R Demo

Simulate a simple EF model!
Create C# classes for your ”table” metadata, with attributes

indicating the primary keys

1 [ DataServiceKey ( ”CustomerID” ) ] 2 public class MyCustomer { 3 public string CustomerID { get ; set ; } 4 public string Name { get ; set ; } 5 . . . 6 }

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HelloWorld PingPong DataEF DataAD

Data Service A#4R Demo

Build IQueryable sequences ≈ SQL tables

1 public IQueryable <MyCustomer> MyCustomers { 2 get { 3 Console . WriteLine ( ” . . . MyCustomers” ) ; 4 return MyCustomers . AsQueryable ( ) ; 5 } 6 }

Build associations MyCustomers ⇔ MyOrders

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