SAIF.Presentation.Web.MVC architecture¶

SAIF.Presentation.Web.MVC is the SAIF in-house Model-View-Controller framework layered on ASP.NET WebForms. It supplies the abstract base types every SAIF WebForms screen derives from — ViewPageBase, ViewControlBase, clsControllerBase, clsModelBase, clsFactoryBase — plus clsContext/clsOnlineContext for cross-application context hand-off persisted in a SQL Server Context table, and NavigationContext for menu-driven page authorization backed by Oracle. It is the only library in this batch that reads configuration, performs data access, and enforces authorization.

Responsibilities¶

Orchestrate the per-request lifecycle for every SAIF WebForms screen: session-timeout handling, authentication/security establishment, per-page menu authorization, model initialization, query-string and cross-application context processing, control-value harvesting, navigation, and centralized error handling.
Provide the abstract base contracts (clsControllerBase, clsModelBase, clsFactoryBase) that consuming applications implement per screen.
Persist and retrieve cross-application context hand-off values in a SQL Server Context table so state can travel with a user navigating between SAIF web applications.
Cache and evaluate a user's authorized menu items (via SAIF.Business.Menu, a project reference within this repository) to answer "may this user reach this app/page?" on every request.
Restore client-side input focus and render diagnostic script markers as part of the WebForms page lifecycle.

Component boundaries¶

View layer — ViewPageBase (extends System.Web.UI.Page) / ViewControlBase (extends System.Web.UI.UserControl): own the ASP.NET lifecycle, view identity (ViewID), view-state persistence strategy, message display, and error surfacing. Contain no business logic.
Controller layer — clsControllerBase: converts raw HTTP into framework actions (initialize → security → menu authorization → model init → query string → context → retrieve → uninitialize); owns navigation and error routing.
Model layer — clsModelBase: holds screen state, user preferences, and the validate-then-write contract (ValidateData/WriteData). Concrete models live in consuming applications.
Construction — clsFactoryBase: each screen supplies a factory returning its controller and model, decoupling the base page from concrete types.
Context layer — clsContext (+ clsOnlineContext): a named key/value bag with well-known typed keys (claimId, policyNum, SAIFClaimNum, ProviderLocationSeqNum) and a private nested SQL Server repository (clsContextRepository) that transfers those values between applications within a session.
Authorization layer — NavigationContext: caches the user's authorized menu items (loaded over Oracle through SAIF.Business.Menu) and answers page-authorization queries.

Interaction model¶

Every derived .aspx page's Page_Init obtains its controller from clsFactoryBase and calls clsControllerBase.Initialize, which runs the fixed sequence: session-timeout check → SecurityCheck (establish clsSecurityPrincipal, emit STYPE cookie, or 401/deny) → lazy NavigationContext construction into Session("navdata") → RedirectUnauthorizedUsers (menu authorization) → Model.Pre_Init/Load → query-string and cross-application context processing.
Cross-application navigation (clsControllerBase.Navigate) persists context key/value rows to the SQL Server Context table before redirecting; the receiving application's Initialize → CheckContext retrieves and deletes those rows, making the hand-off single-use.*
Page authorization is entirely menu-data-driven: NavigationContext loads the user's authorized (applicationCode, pageLink) set from Oracle via SAIF.Business.Menu, cached in session for the duration of the session.*
Consuming applications derive concrete pages/controls/controllers/models from the five base types; there is no runtime plugin or reflection-based discovery — wiring is by inheritance and a per-screen factory.

Architecture diagram¶

The following diagram shows the lifecycle a request follows through the MVC base classes and their downstream collaborators.

flowchart TD
    A["Browser request<br>derived .aspx"] --> B["ViewPageBase.Page_Init"]
    B --> C["clsFactoryBase.GetController"]
    C --> D["clsControllerBase.Initialize"]
    D --> E["SecurityCheck<br>clsSecurityPrincipal"]
    E --> F["NavigationContext<br>Session(navdata)"]
    F --> G["SAIF.Business.Menu<br>authorized menu items (Oracle)"]
    F --> H["RedirectUnauthorizedUsers"]
    H --> I["Model.Pre_Init + Load<br>clsModelBase"]
    I --> J["CheckContext<br>clsContext / SQL Server Context table"]
    J --> K["Derived Retrieve<br>control values"]
    K --> L["UnInitialize<br>persist model + viewdata"]

Sequence diagram¶

The following diagram shows cross-application context hand-off, the primary inter-application interaction owned by this library.

sequenceDiagram
    participant A as App A controller
    participant DB as SQL Server Context table
    participant B as App B controller
    A->>A: Navigate(TargetApp, TargetView)
    A->>DB: SaveContext(SessionID) - delete then insert rows
    A->>B: Response.Redirect(/TargetApp/TargetView)
    B->>B: Initialize -> CheckContext(referrer path)
    B->>DB: RetrieveContext(SourceApp, CurrentApp, SessionID)
    DB-->>B: context rows
    B->>DB: Delete(SourceApp, SessionID)
    B->>B: HandleContext(values) - derived class applies them

Design constraints¶

No class in this library inherits from clsBusinessBase, IBusinessCriteria, or any other BOF business-object base type; this library is a screen/request-orchestration framework, not a business-object library.
Menu-based authorization is session-cached: a revoked grant persists in Session("navdata") until the session ends or is explicitly cleared, so authorization changes are not immediately effective.*
Two database engines are used directly by consumers of this library: SQL Server (Context hand-off table, database APPM, application tag NETFRAMEWORK) and Oracle (menu authorization data, schema/user MENU, delegated to SAIF.Business.Menu); both are hard-coded literals, not configuration-driven.
Nine runtime configuration keys must be supplied by the hosting application's web.config — this library ships no defaults for any of them (see Dependencies and Configuration).
Environment/network-zone trust decisions (IsInsideClient, clsEnvironment.InternalAddress) hard-code IP address patterns (10.*, 131.131.*.*, 127.0.0.1), coupling error routing and session-timeout behavior to the current network addressing scheme.
Behavior branches on Infragistics control-type names (WEBCURRENCYEDIT, WEBDATETIMEEDIT, WEBMASKEDIT, etc.) and SAIF control names using reflection and string matching, without a direct assembly reference to the Infragistics vendor library.*

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/clsControllerBase.vb
SAIF.Presentation.Web.MVC/clsModelBase.vb
SAIF.Presentation.Web.MVC/clsFactoryBase.vb
SAIF.Presentation.Web.MVC/clsContext.vb
SAIF.Presentation.Web.MVC/clsOnlineContext.vb
SAIF.Presentation.Web.MVC/NavigationContext.vb
SAIF.Presentation.Web.MVC/ViewPageBase.aspx.vb
SAIF.Presentation.Web.MVC/ViewControlBase.ascx.vb