ViewPageBase¶

ViewPageBase is the base ASP.NET Page code-behind — the real core of this library's "MVC-style" retrofit onto WebForms. It owns every page lifecycle event (Page_Init, Page_Load, Page_PreRender, Page_Unload, Page_Error), delegates all non-rendering behavior to a clsControllerBase instance, manages ViewState-in-session persistence (BR-MVC-007), and drives centralized error routing via ProcessError (see Error handling).

Purpose¶

Wires each concrete page to its clsFactoryBase/clsControllerBase pair and drives the shared initialization/retrieval/error pipeline from ASP.NET's page lifecycle events.
Implements session-based ViewState persistence for external or explicitly flagged users, reducing ViewState payload size at the cost of server-side session memory (BR-MVC-007).
Supports multiple concurrent model instances per session via a generated ViewID (__SAIFPID), enabling the multi-model navigation pattern used by clsControllerBase.Navigate2.
Generates Infragistics-control-aware client-focus JavaScript via its nested NavigationManager class, using reflection rather than a compile-time Infragistics.* reference.

Context¶

Namespace: SAIF.Presentation.Web.MVC
Assembly/package: SAIF.BOF.Presentation.Web.Infragistics103 (source-bundled)

Public members¶

Member	Signature	Purpose
`PageModeEnum`	`Public Enum PageModeEnum`	Enumerates the page's display mode (e.g., add/edit/view).
`VIEWSTATE_CTRL_ENUM`	`Public Enum VIEWSTATE_CTRL_ENUM`	Enumerates ViewState-in-session behavior options (e.g., `ALL_USERS`, `EXTERNAL_USERS`, likely a default/off value) consumed by BR-MVC-007.
`MessageControl`	`Public Property MessageControl() As Label`	The page's designated label control for displaying status/error messages to the user.
`PageMode`	`Public Property PageMode() As PageModeEnum`	The page's current display mode.
`ViewStateInSession`	`Public Property ViewStateInSession() As VIEWSTATE_CTRL_ENUM`	Configures which users get server-side (session-based) ViewState persistence rather than the default page-embedded ViewState; see BR-MVC-007.
`PageStatePersister`	`Protected Overrides ReadOnly Property PageStatePersister() As System.Web.UI.PageStatePersister`	Overrides the base ASP.NET behavior to return a session-based persister when `ViewStateInSession = ALL_USERS`, or `EXTERNAL_USERS` (or the `EXT_VIEWSTATE_SESSION` AppSettings flag) combined with a non-internal (`10.*`) host address; enforces BR-MVC-007.
`ViewID`	`Public Property ViewID() As String`	The GUID identifying this page's model/view-data instance in session, seeded from the `__SAIFPID` query string/hidden field/session value when multi-model support is in play.
`HandleApplicationError`	`Protected Friend Overridable Function HandleApplicationError(ByVal ex As Exception) As Boolean`	Overridable hook giving the concrete page a chance to fully handle an unhandled exception itself; if it returns `True`, `ProcessError` takes no further action — see Error handling.

Nested types¶

Type	Kind	Purpose
`NavigationManager`	`Protected Class NavigationManager`	Generates client-side focus-management JavaScript for a bound control, with Infragistics-control-aware branching (`WebCombo`, `WebDataInput`, `WebSchedule.WebDateChooser`, including a v4.3-specific branch) and `SAIF.UIControls.SAIFWebMaskEdit`/`SAIFWebDateTimeEdit` detection, all via reflection on `GetType.FullName` rather than compile-time `Infragistics.*` references.

NavigationManager members¶

Member	Signature	Purpose
`SelectText`	`Public Property SelectText() As Boolean`	Whether the generated focus script should also select the bound control's text content.
`BoundControlId`	`Public WriteOnly Property BoundControlId() As System.Web.UI.Control`	Sets the control whose client-side focus script will be generated.
`BoundControlName`	`Public ReadOnly Property BoundControlName() As String`	The resolved client-side name/ID used in the generated focus script for the bound control.
`GenerateScripts`	`Public Sub GenerateScripts()`	Emits the client-focus JavaScript for the bound control during `Page_PreRender`.

Inherited public members¶

Members in this section are inherited from System.Web.UI.Page (and its base System.Web.UI.TemplateControl/System.Web.UI.Control). They are available on this type through inheritance and are commonly used by consumers of ViewPageBase-derived pages.

Member	Signature	Purpose	Origin
`IsPostBack`	`Public ReadOnly Property IsPostBack() As Boolean`	Read by `ViewPageBase.Page_Init`/`Page_Load` to decide whether to run the controller's initial-retrieval logic (fresh request) or its postback/input-processing logic, driving the shared MVC-style pipeline's branching.	`System.Web.UI.Page`
`Session`	`Public ReadOnly Property Session() As HttpSessionState`	Backs both the multi-model `ViewID` lookup and the session-based ViewState store that `PageStatePersister` writes to for external or flagged users (BR-MVC-007).	`System.Web.UI.Page`
`Request`	`Public ReadOnly Property Request() As HttpRequest`	Supplies the `__SAIFPID` query string/hidden-field value `ViewID` reads to select the correct model instance, and the host address `PageStatePersister` inspects to decide whether session-based ViewState applies.	`System.Web.UI.Page`
`Response`	`Public ReadOnly Property Response() As HttpResponse`	Used by controller-driven navigation (for example `clsControllerBase.Navigate2`) to redirect between pages while carrying the `ViewID` needed to resume the correct model instance.	`System.Web.UI.Page`
`Server`	`Public ReadOnly Property Server() As HttpServerUtility`	Provides server-side utility operations (such as error transfer) available to `ProcessError` and other controller-driven error-handling code.	`System.Web.UI.Page`
`Cache`	`Public ReadOnly Property Cache() As Cache`	Standard ASP.NET application-wide `Cache` accessor exposed on the page; no library-specific caching usage by `ViewPageBase` or `clsControllerBase` is established in source.**	`System.Web.UI.Page`
`ClientScript`	`Public ReadOnly Property ClientScript() As ClientScriptManager`	Used by `Navigate` to register the client-side script that opens popup windows as part of the page's navigation behavior.	`System.Web.UI.Page`
`User`	`Public ReadOnly Property User() As IPrincipal`	Standard ASP.NET authenticated-principal accessor exposed on the page; the internal/external classification `PageStatePersister` actually applies for BR-MVC-007 is derived from `Request.UserHostAddress`, not from `User`, so no library-specific use of this property is established in source.**	`System.Web.UI.Page`
`Controls`	`Public ReadOnly Property Controls() As ControlCollection`	Exposes the page's top-level control tree so `NavigationManager` and `FindControl` can locate the specific bound Infragistics/SAIF input control targeted by `BoundControlId`.	`System.Web.UI.Control`
`Visible`	`Public Property Visible() As Boolean`	Lets `PageMode`-driven controller logic hide or show the page's rendered content as a unit (for example while an error is being handled).	`System.Web.UI.Control`
`ViewState`	`Protected ReadOnly Property ViewState() As StateBag`	Holds the page's postback state; `ViewPageBase.PageStatePersister` governs whether this is physically stored in the page (default) or in session, per BR-MVC-007.	`System.Web.UI.Control`
`DataBind`	`Public Overridable Sub DataBind()`	Standard ASP.NET data-binding entry point on the page; no call site in `ViewPageBase` or `NavigationManager` is established in source, so any invocation by a derived page's own code-behind is outside this library's traced behavior.**	`System.Web.UI.Control`
`FindControl`	`Public Function FindControl(ByVal id As String) As Control`	Used by `NavigationManager` to resolve the specific input control identified by `BoundControlId` before generating its client-focus script.	`System.Web.UI.Control`
`OnInit`	`Protected Overridable Sub OnInit(ByVal e As EventArgs)`	Raises the `Init` event; `ViewPageBase.Page_Init` builds on this lifecycle stage to construct the page's `clsFactoryBase`/`clsControllerBase` pair.	`System.Web.UI.Control`
`OnLoad`	`Protected Overridable Sub OnLoad(ByVal e As EventArgs)`	Raises the `Load` event; `ViewPageBase.Page_Load` builds on this lifecycle stage to trigger the controller's initial-retrieval or postback-processing logic based on `IsPostBack`.	`System.Web.UI.Control`

Behavioral notes¶

ViewPageBase.aspx (the markup partner file) declares Inherits="SAIF.ViewPageBase" — a namespace (SAIF) inconsistent with the project's actual root namespace (SAIF.Presentation.Web.MVC), suggesting this markup file is legacy scaffolding not served directly; real markup for consuming pages lives in each downstream application project.*
PageStatePersister's decision to use session-based ViewState combines a page-level ViewStateInSession enum setting with the EXT_VIEWSTATE_SESSION AppSettings flag and a runtime host-address check — three independent inputs converging on one persistence decision (BR-MVC-007).
ProcessError (invoked from Page_Error, not itself a listed public member above since it is triggered by the ASP.NET event pipeline rather than called directly) dispatches to HandleApplicationError, then SAIF-exception-type-specific handling, then clsControllerBase.HandleErrors — see Error handling for the full sequence.

Constraints and usage notes¶

HandleApplicationError returning True fully suppresses the remaining SAIF-exception dispatch and clsControllerBase.HandleErrors call — concrete pages must ensure they have genuinely handled the error (e.g., displayed a message) before returning True.

Note: Statements marked with * were inferred from code structure, naming conventions, or contextual evidence where direct confirmation was not available in source artifacts. Statements marked with ** could not be confirmed; treat as unknown until verified.

Sources¶

SAIF.Presentation.Web.MVC\ViewPageBase.aspx.vb
SAIF.Presentation.Web.MVC\ViewPageBase.aspx