Spring's ASP.NET AJAX integration allows for a plain CLR object (POCO), that is one that doesn't have any attributes or special base classes, to be exported as a web service, configured via dependency injection, 'decorated' by applying AOP, and then exposed to client side JavaScript.
Spring.NET, and particularly Spring.Web, improved support
for web services in .NET with the
WebServiceExporter
. Exporting of an ordinary plain
.NET object as a web service is achieved by registering a custom
implementation of the WebServiceHandlerFactory
class as the HTTP handler for *.asmx
requests.
Microsoft
ASP.NET AJAX introduced a new HTTP handler
System.Web.Script.Services.ScriptHandlerFactory
to
allow a Web Service to be invoked from the browser by using
JavaScript.
Spring's integration allows for both Spring.Web and ASP.NET AJAX functionality to be used together by creating a new HTTP handler.
The WebServiceExporter
combined with the
new HTTP handler exposes POCOs as Web Services in your ASP.NET AJAX
application.
In order for a Web service to be accessed from script, the
WebServiceExporter
should decorate the Web
Service class with the ScriptServiceAttribute
.
The code below is taken from the sample application
Spring.Web.Extensions.Sample, aka the 'AJAX' shortcut in the
installation. :
<object id="ContactWebService" type="Spring.Web.Services.WebServiceExporter, Spring.Web"> <property name="TargetName" value="ContactService"/> <property name="Namespace" value="http://Spring.Examples.Atlas/ContactService"/> <property name="Description" value="Contact Web Services"/> <property name="TypeAttributes"> <list> <object type="System.Web.Script.Services.ScriptServiceAttribute, System.Web.Extensions"/> </list> </property> </object>
All that one needs to do in order to use the
WebServiceExporter
is:
1. Configure the Web.config file of your ASP.NET AJAX application as a Spring.Web application.
<sectionGroup name="spring"> <section name="context" type="Spring.Context.Support.WebContextHandler, Spring.Web"/> </sectionGroup>
<spring> <context> <resource uri="~/Spring.config"/> </context> </spring>
2. Register the HTTP handler and the Spring HttpModule
under the system.web
section.
<httpHandlers> <remove verb="*" path="*.asmx"/> <add verb="*" path="*.asmx" validate="false" type="Spring.Web.Script.Services.ScriptHandlerFactory, Spring.Web.Extensions"/> <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/> </httpHandlers> <httpModules> <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="SpringModule" type="Spring.Context.Support.WebSupportModule, Spring.Web"/> </httpModules>
3. Register the HTTP handler and the Spring HttpModule
under system.webServer
section.
<modules> <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="SpringModule" type="Spring.Context.Support.WebSupportModule, Spring.Web"/> </modules> <handlers> <remove name="WebServiceHandlerFactory-Integrated" /> <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="Spring.Web.Script.Services.ScriptHandlerFactory, Spring.Web.Extensions"/> <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> </handlers>
You can find a full Web.config file in the example that comes with this integration.
A proxy class is generated for each Web Service. Calls to Web
Services methods are made by using this proxy class. When using the
WebServiceExporter
, the name of the proxy class
is equal to the WebServiceExporter
's id.
// This function calls the Contact Web service method // passing simple type parameters and the callback function function GetEmails(prefix, count) { ContactWebService.GetEmails(prefix, count, GetEmailsOnSucceeded); }