{"id":7,"date":"2008-07-22T10:14:00","date_gmt":"2008-07-22T14:14:00","guid":{"rendered":"http:\/\/everysport.net\/GamePlan3\/Default.aspx?tabid=489&EntryID=11"},"modified":"2008-10-17T12:10:57","modified_gmt":"2008-10-17T16:10:57","slug":"configuring-custom-inavigationservice-in-wcsf-contrib-library-updated","status":"publish","type":"post","link":"https:\/\/archive.blogs.harvard.edu\/brandonhaynes\/2008\/07\/22\/configuring-custom-inavigationservice-in-wcsf-contrib-library-updated\/","title":{"rendered":"Configuring custom INavigationService in WCSF Contrib library (Updated)"},"content":{"rendered":"

I recently wrote<\/span><\/a> about implementing a custom PageFlow navigation provider in the WCSF library.\u00a0 Since then, the patterns team has broken out the PageFlow block into a separate package (formally the “Patterns & Practices: Web Client Software Factory Contrib<\/span><\/a>“).<\/p>\n

Since my existing PageFlow navigation provider-related modifications became obsolete with this change, I thought I’d spend a few minutes porting my changes to the new block.\u00a0 I actually completed this task a couple of months ago, but have just now found the time to post it publicly.\u00a0 Thanks to those who persevered in prodding me to put it online!<\/p>\n

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WCSF Changes<\/h3>\n

The web.config setting is identical to the original setting, marked up as:<\/p>\n

<<\/span>pageFlowProvider<\/span> providerType<\/span>=\"WCSFContrib.PageFlow.Xml.XmlPageFlowProvider, WCSFContrib.PageFlow.Xml\"<\/span> navigationType<\/span>=\"[Fully Qualified Assembly Name]<\/strong>\"<\/span> \/><\/span><\/pre>\n
This change is picked up through an addition to Configuration\/PageFlowProviderSection.cs, as:<\/pre>\n
        \/\/\/ <summary><\/span>\r\n        \/\/\/ Defines the concrete type of the INavigator.<\/span>\r\n        \/\/\/ <\/summary><\/span>\r\n        [ConfigurationProperty(\"navigationType\"<\/span>, DefaultValue = \"WCSFContrib.PageFlow.Services.NavigationService\"<\/span>, IsRequired = false<\/span>)]\r\n        public<\/span> string<\/span> NavigationType\r\n            {\r\n            get { return<\/span> (string<\/span>)base<\/span>[\"navigationType\"<\/span>]; }\r\n            }<\/pre>\n
\u00a0<\/p>\n
Next, the BuildProvider method of PageFlowDirectory (PageFlowDirectory.cs) must be augmented to pick up the specified provider and load it (changes in bold):<\/p>\n
        private<\/span> static<\/span> IPageFlowProvider BuildProvider()\r\n        {\r\n            PageFlowProviderSection configSection =\r\n                (PageFlowProviderSection) ConfigurationManager.GetSection(\"pageFlow\/pageFlowProvider\"<\/span>);\r\n            PageFlowInstanceStoreProviderSection storeSection =\r\n                (PageFlowInstanceStoreProviderSection) ConfigurationManager.GetSection(\"pageFlow\/pageFlowInstanceStoreProvider\"<\/span>);\r\n            PageFlowInstanceCorrelationTokenProviderSection tokenProviderSection =\r\n                (PageFlowInstanceCorrelationTokenProviderSection)ConfigurationManager.GetSection(\"pageFlow\/pageFlowInstanceCorrelationTokenProvider\"<\/span>);\r\n            Type providerType = Type.GetType(configSection.ProviderType);\r\n            Type navigationType = Type.GetType(configSection.NavigationType);\r\n<\/strong>\r\n            if<\/span> (navigationType == null<\/span>)\r\n                throw<\/span> new<\/span> InvalidOperationException(\"Invalid navigationType specified: \"<\/span> + configSection.NavigationType);\r\n\r\n            Services.INavigationService navigationService = (Services.INavigationService)Activator.CreateInstance(navigationType);\r\n<\/strong>            _provider = (IPageFlowProvider)Activator.CreateInstance(providerType,\r\n                                                                    BindingFlags.CreateInstance,\r\n                                                                    null<\/span>,\r\n                                                                    new<\/span> object<\/span>[] { navigationService, storeSection, tokenProviderSection },\r\n<\/strong>                                                                    CultureInfo.CurrentCulture);\r\n            return<\/span> _provider;\r\n        }<\/pre>\n
Finally, each concrete provider must be modified to accept the appropriate navigationService as a constructor parameter. In the case of the XmlPageFlowProvider, this would result in the following changes (highlighted in bold):<\/p>\n
        public<\/span> XmlPageFlowProvider(INavigationService navigationService, ...)\r\n        {\r\n            if<\/span> (pageFlowInstanceStoreProviderSection == null<\/span>)\r\n                throw<\/span> new<\/span> ArgumentNullException(\"pageFlowInstanceStoreProviderSection\"<\/span>);\r\n\r\n            if<\/span> (pageFlowCorrelationTokenProviderSection == null<\/span>)\r\n                throw<\/span> new<\/span> ArgumentNullException(\"pageFlowCorrelationTokenProviderSection\"<\/span>);\r\n\r\n            IDictionary<string<\/span>, NavigationGraph> navigationGraphs = new<\/span> WebConfigStore().GetXmlPageFlowNavigationGraphs();\r\n\r\n            _pageFlowFactory = new<\/span> XmlPageFlowFactory(navigationGraphs, navigationService);\r\n  <\/strong>          \/\/_pageFlowFactory = new XmlPageFlowFactory(navigationGraphs, new NavigationService());<\/span>\r\n\r\n            Type tokenProviderType = Type.GetType(pageFlowCorrelationTokenProviderSection.ProviderType, true<\/span>, true<\/span>);\r\n            IPageFlowCorrelationTokenProvider _tokenProvider =\r\n                (IPageFlowCorrelationTokenProvider)Activator.CreateInstance(tokenProviderType);\r\n\r\n            Type storeType = Type.GetType(pageFlowInstanceStoreProviderSection.ProviderType, true<\/span>, true<\/span>);\r\n            _store =\r\n                (IPageFlowInstanceStore)Activator.CreateInstance(storeType, BindingFlags.CreateInstance, null<\/span>,\r\n                                                                  new<\/span> object<\/span>[]\r\n                                                                      {\r\n                                                                          pageFlowInstanceStoreProviderSection.ConnectionStringName,\r\n                                                                        _tokenProvider\r\n                                                                      },\r\n                                                                  CultureInfo.CurrentCulture);\r\n            PopulateDirectory(navigationGraphs);\r\n         }<\/pre>\n
As a footnote, I did consider modifying the NavigationService directly to instantiate and decorate an underlying custom NavigationProvider. While this might have resulted in one less code change, I do not feel that it is of optimal design. Concrete PageFlow providers should not be responsible for instantiation of their navigationProviders; these objects should be injected, for maximum flexibility.\u00a0<\/p>\n
Downloads<\/h3>\n