--- title: SAIF.NetCore.Common overview summary: High-level purpose, scope, and responsibilities for this library. status: draft owner: Framework.NCore maintainers last_reviewed: 2026-10-02 library: SAIF.NetCore.Common reference_type: package --- # SAIF.NetCore.Common overview > **Documentation context:** Packaged Component (NuGet) `SAIF.NetCore.Common` is a foundation-layer, general-purpose utility library for the Framework.NCore mono-repo: it provides stateless string, date, date-range, collection, byte, URI, and identity extension methods, argument-guard helpers, a validation-result model, MVC-oriented context exception types, and sequence-generator value types, with zero SAIF package dependencies and zero third-party package dependencies. ## Purpose - Provide reusable, dependency-free BCL-type extensions and helpers that any SAIF application or library can call for string manipulation, date/date-range evaluation, byte-array search, dictionary merging, enumerable operations, numeric parsing, URI parsing, and Windows identity parsing. - Provide a small set of value and exception types — `DateRange`/`NullableDateRange`, a `ValidationResult`/`ValidationFailure`/`SaifValidationException` validation model, `ContextException` and its four subclasses, and a `SequenceGenerator` hierarchy (`LongSequence`, `Sequence`) — for consumers that need these shared shapes without a heavier dependency. - Sit at the very bottom of the dependency graph: the `.csproj` has no `` and no `` elements, and no library currently present in this repository references it.* ## Responsibilities - Declare extension methods for `string`, `bool`, `DateTime`, `DateRange`, `IDictionary`, `Exception`, `Expression`, `Stream`, generic `T`, `IComparable`, `IEnumerable`, numeric types, `IIdentity`, `byte[]`, and `Uri` (`Extensions` namespace). - Provide static helper classes: `DateMaker` (EDI-style date strings), `Enforce` (argument guard clauses), `Julian` (Julian-date conversions), and `Reflector` (property-info reflection) (`Helpers` namespace). - Provide a validation-result model (`ValidationResult`, `ValidationFailure`) and `SaifValidationException` for surfacing validation failures to callers. - Provide MVC-oriented context exception types (`ContextException` and its four subclasses) whose `TargetView` values imply ASP.NET MVC view-routing intent in consuming applications.* - Provide shared enums (`ContiguousOptions`, `DateRangeOverlapResult`, `IncludeComparisons`, `LogType`, `OverlappingDateOptions`), several of which duplicate nested enums declared on the extension classes themselves. ## Key components - `Extensions`: 15 static extension classes, each scoped to one BCL type or concern. - `Helpers`: `DateMaker`, `Enforce`, `Julian`, and `Reflector` — 4 public static helper classes, plus the internal marker attribute `ValidatedNotNullAttribute` used only as a code-analysis hint on `Enforce.ArgumentNotNull`. - `InternalUtility.TitleCase`: an `internal` engine class that backs `StringExtensions.ToTitleCase`; it is not part of the public surface. - `Types`: 14 public types covering exception hierarchies, date-range value types, an empty placeholder (`EntityBase`), and the sequence-generator hierarchy. - `Enums`: 5 top-level enums, three of which (`ContiguousOptions`, `IncludeComparisons`, `OverlappingDateOptions`) are shadowed by functionally identical enums declared elsewhere in the assembly and are not bound by the library's own call sites.* - The library's own README (`src/SAIF.NetCore.Common/README.md`) states this package "should never be a dependency of the NetCore.Services packages", but the repository's `Architecture.md` describes implementation libraries as referencing "`ServiceContracts` (and sometimes `Common`)". No `.csproj` under `src/` in this repository currently references `SAIF.NetCore.Common`, so the observed state matches the README, and the "sometimes" wording in `Architecture.md` could not be confirmed against any concrete consumer in this repository.** - No project references between libraries in this repository touch `SAIF.NetCore.Common`; it takes zero package references of any kind, SAIF or third-party, consistent with its foundation-layer, zero-dependency position in [`Architecture.md`](../../../Architecture.md). - Nearly every helper and extension class is `static` and stateless, with one documented exception: `DateRange.Empty` is a shared static instance whose `BeginDate`/`EndDate` have public setters, so any consumer that mutates it changes the value process-wide.* - Several members read `DateTime.Now`/`DateTime.Today` or the current thread culture directly, so their results depend on server clock, time zone, and locale (see [Architecture](architecture.md)). ## Related documentation - [Index](index.md) - [Architecture](architecture.md) - [Dependencies](dependencies.md) - [Operations and processes](operations-processes.md) - [Business rules](business-rules.md) - [API reference](api/index.md) > **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 - `src/SAIF.NetCore.Common/SAIF.NetCore.Common/SAIF.NetCore.Common/SAIF.NetCore.Common.csproj` - `src/SAIF.NetCore.Common/README.md` - `Architecture.md`