clsModelBase¶

clsModelBase is the abstract Model-layer contract of this library's WebForms MVC retrofit. It owns a clsContext (cross-application state) and a clsPreferences (user/application preference lookup, from SAIF.Presentation), defines the ValidateData/WriteData template method behind BR-MVC-006, and provides shared input-validation helper methods used by concrete models across the SAIF web application suite.

Purpose¶

Guarantees that persistence (WriteData) never runs without a prior successful validation (ValidateData) via the Write() template method (BR-MVC-006).
Lazily initializes the concrete model exactly once per session (Pre_Init) and loads the current user's clsPreferences for the model's application.
Supplies reusable string/number/date/future-date validation helpers so concrete models do not need to reimplement basic input checks.

Context¶

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

Public members¶

Member	Signature	Purpose
`Context`	`Public Property Context() As clsContext`	The cross-application context bag for this model instance; initialized to a new `clsContext` in the constructor.
`LastError`	`Public Property LastError() As String`	Holds the most recent error message set by the concrete model, e.g., during validation failures.
`Preferences`	`Public ReadOnly Property Preferences() As clsPreferences`	The current user's preferences for this model's application, populated during `Pre_Init()`; `Nothing` until `Pre_Init()` has run.
`SecurityPrincipal`	`Public Property SecurityPrincipal() As clsSecurityPrincipal` (marked `Obsolete`)	Forwards to `Context.SecurityPrincipal`; deprecated in favor of accessing `Context.SecurityPrincipal` directly.
`ValidateData`	`Protected Friend MustOverride Function ValidateData() As Boolean`	Abstract hook the concrete model implements to validate its current in-memory state before a write; gates whether `WriteData()` runs (BR-MVC-006).
`WriteData`	`Protected Friend MustOverride Function WriteData() As Boolean`	Abstract hook the concrete model implements to persist its current in-memory state; only invoked by `Write()` when `ValidateData()` returns `True`.
`Initialize`	`Protected Friend Overridable Sub Initialize()`	Overridable hook for one-time concrete-model setup, invoked exactly once per model instance from `Pre_Init()`; no-op by default.
`UnInitialize`	`Protected Friend Overridable Sub UnInitialize()`	Overridable hook for concrete-model teardown; no-op by default.
`New()`	`Public Sub New()`	Initializes `Context` to a new `clsContext` instance.
`Write`	`Protected Friend Function Write() As Boolean`	Template method: calls `ValidateData()`, and only if it returns `True`, calls `WriteData()`; returns the eventual result or `False` if validation failed (BR-MVC-006).
`IsValidString`	`Protected Function IsValidString(ByVal Value As String) As Boolean`	Returns `False` if `Value` is `Nothing` or, after trimming, an empty string; otherwise `True`.
`IsValidNumber`	`Protected Function IsValidNumber(ByVal Value As String) As Boolean`	Returns `True` only if `Value` passes `IsValidString` and `IsNumeric(Value)`.
`IsValidDate`	`Protected Function IsValidDate(ByVal Value As String) As Boolean`	Returns `True` only if `Value` passes `IsValidString` and `IsDate(Value)`.
`IsValidFutureDate` (String overload)	`Protected Function IsValidFutureDate(ByVal Value As String) As Boolean`	Returns `True` only if `Value` is a valid, non-empty date strictly later than today's date (compared by short-date string).
`IsValidFutureDate` (Date overload)	`Protected Function IsValidFutureDate(ByVal Value As Date) As Boolean`	Returns `True` only if `Value` is strictly later than today's date (compared by short-date string).

Behavioral notes¶

Pre_Init() is Friend-scoped and marked <DebuggerStepThrough()>; it is invoked by clsControllerBase.Initialize() and Navigate2, not called directly by consuming pages.
Preferences is constructed using Context.SecurityPrincipal.UserName() and Context.ApplicationName — if Pre_Init() runs before SecurityCheck() has populated SecurityPrincipal, this would raise a null-reference error; in practice clsControllerBase.Initialize() always calls SecurityCheck() before Model.Pre_Init().*

Constraints and usage notes¶

ValidateData/WriteData/Retrieve-style concrete behavior is entirely defined by consuming applications; this library provides only the ordering contract and validation helpers.
IsValidFutureDate compares dates using ToShortDateString, meaning time-of-day components are ignored — "today" itself is not considered a future date.

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\clsModelBase.vb