Laurent Guérin / V / 2009 June. ( for Telosys and + )

Transcription

1 s Laurent Guérin / V / 2009 June ( for Telosys and + ) What is a Telosys service? A Telosys service is a Java method ( "execute " ) that can be called from the client side with an HTTP request ( GET or POST ) input : Http request parameters environment : User screen session gives access to : all screen contexts standard http session Application level objects output : XML response or full page A service is not linked with a particular Context ( to work in a specific Context use an exec action ) Telosys framework - s ( Laurent Guérin / ver 1.3 ) 2 Telosys 1

2 What is a Telosys service? The service ( Java method ) is called from the client-side ( via AJAX call, link, ) The JavaScript framework provides a object and object A new instance of the service is created for each call => a service is thread safe Client Javascript AJAX framework 1 3 request response The service response contains the appropriate HTTP headers to avoid browser caching effects 2 Server processing Session Telosys framework - s ( Laurent Guérin / ver 1.3 ) 3 Different kinds of services AJAX services ( RPC services ) Return : XML response Without renderer no view in the response (only values) With renderer(s) view(s) in the XML response Usage : Remote Procedure Call ( to retrieve and use the result in the same page ) Navigation services : Return : full HTML page ( Map, any page, ) Usage : classical page navigation ( to replace the current page or open a new window ) Telosys framework - s ( Laurent Guérin / ver 1.3 ) 4 Telosys 2

3 AJAX (RPC) services Telosys service : Request & Request : Http GET/POST request with the service name and a query string (parameters). Example : ( class ) : 0..N Values 0..1 Result object ( Object ) 0..1 View ( produced by a "renderer" ) Client Call name.svc Via URL with query string ret code Params XML Values Result name Server Result? View Telosys framework - s ( Laurent Guérin / ver 1.3 ) 6 Telosys 3

4 How to create & use a service 1 Create the service ( = create a Java Class ) interface << interface >>. init(). execute(). getrenderer(). getname(). getsessionkey() Standard << abstract >>. init(). getrenderer(). getname(). getsessionkey() Standard base class to build services The service My. execute() return null; XML response (AJAX) return view; HTML response (navigation) Only one method execute Parameters :. Session. Request. Return type : View Telosys framework - s ( Laurent Guérin / ver 1.3 ) 7 How to create & use a service Example : Only one method to implement public class My extends Standard public View execute ( Session screensession, Request servicerequest, service ) throws TelosysException System.out.println("Test : execute()"); //--- Processing... User Session Input parameters to build //--- Set response message service.addmessage( new Message("Test message.", Message.INFORMATION)); //--- Set response result service.setresult("result object (here a String)"); //--- Set response values service.setvalue("resultv1", "V1"); service.setvalue("resultv2", "V2"); //--- Return : null = no navigation return null ; // return null for AJAX call ( generate an XML response ) Return Type of response :. return null : for AJAX call (response in XML). return View : for navigation (forward to the view) Telosys framework - s ( Laurent Guérin / ver 1.3 ) 8 Telosys 4

5 How to create & use a service 2 Register (declare) the service in the Registry Symbolic name Implementation class Renderer (optional) Session key (optional) Example : «name» class Optional : A service can be called by its class name if the class is in a predefined package Registry // Parameters : // Name, Class, Renderer, SessionKey register("myserv", My.class, null, null ); register("l002", L002.class, "renderer/l001.jsp", Const.SVC_L002_RESULT ); register("l003", L003.class, "renderer/l001.jsp", null ); register("l002bis", L002.class, null, null ); register("t001", T001.class, "renderer/t001.jsp", null ); registerpackage ( "org.samples.service" ); registerpackage ( "org.samples.other" ) ; default packages location (for invocation by class name) Telosys framework - s ( Laurent Guérin / ver 1.3 ) 9 How to create & use a service 3 Test the service directly from the browser A service is called by its "symbolic name" ( or class name ) + ".svc" Call ( http request ) XML Telosys framework - s ( Laurent Guérin / ver 1.3 ) 10 Telosys 5

6 How to create & use a service 4 Use (call) the service with JavaScript Example : //--- Get a service instance var service = telosys.get( "MyServ", show); function call() Method to call the service var sarg1 = fwkgetvalue("arg1"); var sarg2 = fwkgetvalue("arg2"); service.call(sarg1, sarg2); // Call with generic parameters (p1=..,p2=..) function show(o) // o if ( o.isok() ) var sresult = o.getvalue("result"); alert ( "OK : Result = " + sresult ); fwksetvalue("result", sresult); Put the result else in a field name Callback method alert( "ERREUR : " + o.getreturncode() + " - " + o.getreturnmessage() ); Method to process the service response Get a returned value Telosys framework - s ( Laurent Guérin / ver 1.3 ) 11 How to create & use a service A service can be called with "anonymous parameters" or with "named parameters" : service.call() anonymous parameters service.callwithparams() named parameters Client side ( JavaScript ) Server side ( Java ) function call() var x = "123"; service.call ( x, "abcd", 456, "foo" ); req.getparameter(1); req.getparameter(2); req.getparameter(3); etc... function call() var params = new Object(); params["code"] = "123" ; params["name"] = "Bart"; service.callwithparams( params ); req.getparameter("code"); req.getparameter("name"); Telosys framework - s ( Laurent Guérin / ver 1.3 ) 12 Telosys 6

7 Advanced AJAX (RPC) services How to produce a view A service can produce a page fragment, on the server-side, by generating a view. The view can be directly print in a part of the user screen To build a view after a service call assign a renderer (a JSP) to the service The built view is transported as a part of the XML response it can be used with result values Call name.svc Via URL with query string ret code Params XML Values View include Server Renderer JSP Result Telosys framework - s ( Laurent Guérin / ver 1.3 ) 14 Telosys 7

8 How to use the view on the client side // Parameters : // Name, Class, Renderer, SessionKey register("myserv", My.class, "renderer/l001.jsp", null ); Registry name Callback method //--- Get a service instance var service = telosys.get( MyServ", show); JavaScript function call() Method to call the service var snom = fwkgetvalue("nom"); var sprenom = fwkgetvalue("prenom"); service.call(snom, sprenom); // Call with generic parameters (p1=..,p2=..) function show(o) fwkshowview("containerid",o); Method to process the service response Get the view part of the response ( produced by the service renderer ) and put it in the container widget Telosys framework - s ( Laurent Guérin / ver 1.3 ) 15 stateless or statefull services? By default a service is stateless (the result is not kept after execution) To store a service result assign a session key to the service the result and the renderer are stored in the screen session with that key reusable Processor Session session key Result Holder Renderer JSP Result Telosys framework - s ( Laurent Guérin / ver 1.3 ) 16 Telosys 8

9 How to reuse a service result To reuse a service result previously stored in the Session call the service URL with a single parameter action=get Example : /My.svc?action=get The result and the renderer retrieved in the session are used to produce the view again. XML View Processor Renderer No service execution Session Result session key Result Holder JSP Telosys framework - s ( Laurent Guérin / ver 1.3 ) 17 Navigation services Telosys 9

10 Navigation services To navigate just return the target view : public class My extends Standard public View execute ( Session screensession, Request servicerequest, service ) throws TelosysException System.out.println("Test : execute()"); //--- Processing... //--- Set response message service.addmessage( new Message("Test message.", Message.INFORMATION)); //--- Set response result service.setresult("result object (here a String)"); //--- Set response values service.setvalue("resultv1", "V1"); service.setvalue("resultv2", "V2"); //--- Return View view = new ResourceView ( "/dir/page.jsp" ) ; return view ; Telosys framework - s ( Laurent Guérin / ver 1.3 ) 19 Navigation services ( the views ) Different kinds of views : View << interface >>. gettarget(). generate() Standard web resource (page, jsp, servlet,.. ) ResourceView. ResourceView(String) View v = new ResourceView("/dir/page.jsp"); View. View(String, int). View(String, int, String). getid(). getname(). getaction(). gettype(). getmap() Telosys Map View v = new View( My", 0 ); View v = new View( My", 0, "html" ); View v = new View( My", 0, xul" ); Telosys framework - s ( Laurent Guérin / ver 1.3 ) 20 Telosys 10

11 How to populate Views? If the view (or the renderer) is a JSP (classical JSP or ScreeMap), it can use E.L. ( the standard Expression Language ) Telosys Symbolic Variables To provide the useful objects to the view, the service must "expose" them (std request scope) Example : Employee emp =... ; response.expose("employee", emp); response.expose("result", new Integer(123)); <h3>result = $result</h3> <t:field... value="@employee.name" /> View If the View is a Map associated with a Context, it has access to the Context elements via the Symbolic Variables Telosys framework - s ( Laurent Guérin / ver 1.3 ) 21 How to prepare a Context Example : Server 1 Call Params 2 <t:field value="@e.attr" /> The context can be used for fields initialization ( classical MVC pattern ) 2 Open or Use Context Manager oncreate () onreuse() initialize ContextManager.openContext(..,..,..,..) OR ContextManager.useContext(..,..,..,..) return new View( SCREEN2, 0); oncreate () oncreate () or onreuse() Telosys framework - s ( Laurent Guérin / ver 1.3 ) 22 Telosys 11

12 THE END Telosys 12