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EncDotNet.S100.Datasets.S124

Library for reading and portraying IHO S-124 (Navigational Warnings) datasets.

S-124 provides a standard data model for distributing navigational warnings (NAVAREA, coastal, local) as GML-encoded datasets conforming to the S-100 framework.

Features

  • Parse S-124 GML datasets (S-100 Part 10b encoding)
  • Extract navigational warning features (NavwarnPart, NavwarnAreaAffected, TextPlacement)
  • Convert to S-100 Part 9 FeatureXML for portrayal pipeline consumption
  • XSLT-based portrayal via the S-124 Portrayal Catalogue

Overview

Key types include:

  • S124Dataset — root model containing parsed features, information types, and dataset identification. ReadMetadata() (plus static ReadMetadata(path) / ReadMetadata(stream)) is the phased-loading "peek" path (issue #460): it returns a DatasetMetadata with the declared spec and the raw WGS-84 extent folded from feature geometry (null when the dataset carries only geometry-less container features), skipping the XSLT portrayal pipeline.
  • S124Feature — a geographic feature with type code, geometry, simple attributes, complex attributes, and xlink:href references (GmlReference).
  • S124InformationType — a non-geographic information type instance (e.g. NavwarnPreamble).
  • S124ComplexAttribute — a complex attribute instance containing sub-attribute values.
  • S100GeometryType — shared enum (from EncDotNet.S100.Core) describing the geometry primitive type of a feature.
  • FeatureXML projection — there is no S-124-specific source type: the S-124 dataset processor in EncDotNet.S100.Datasets.Pipelines projects an S124Dataset into S-100 Part 9 FeatureXML for the XSLT portrayal rules with the shared GmlFeatureXmlSource<TFeature> from EncDotNet.S100.Core.
  • S124PortrayalCatalogue — IVectorPortrayalCatalogue implementation that loads XSLT rules, symbols, line styles, area fills, and color palettes.

Strongly-typed data model

The types above expose the dataset as a feature bag — schema-agnostic, well suited for the portrayal pipeline, but inconvenient when client code wants to inspect a warning's preamble, parts, or references directly. The EncDotNet.S100.Datasets.S124.DataModel namespace layers a strongly-typed projection on top:

  • S124NavigationalWarning.From(dataset, out diagnostics) — projects an S124Dataset into a typed object graph rooted at the navigational warning, resolving xlink:href cross-references and parsing primitive values.
  • S124NavwarnPreamble with a typed MessageSeriesIdentifier (warning number / year / agency), general area, locality, classification.
  • S124NavwarnPart with restriction code, warning information text, geometry, and resolved AffectedAreas / TextPlacements.
  • S124AffectedArea, S124TextPlacement — features resolved through the FC associations areaAffected and TextAssociation respectively.
  • S124WarningReference with reference category and message reference.
  • S124SpatialQuality with quality-of-position code.
  • Anything the typed model does not understand is preserved on each object's ExtraAttributes dictionary, so extension and future-edition attributes round-trip verbatim.
  • Projection failures (unresolved xlinks, unparseable values, duplicate preambles) surface as ProjectionDiagnostic entries (from EncDotNet.S100.DataModel) rather than exceptions. Only a fully empty dataset throws.

Installation

dotnet add package EncDotNet.S100.Datasets.S124

Quick start (typed model)

using EncDotNet.S100.DataModel;
using EncDotNet.S100.Datasets.S124;
using EncDotNet.S100.Datasets.S124.DataModel;

var dataset = S124Dataset.Open("navwarn.gml");
var warning = S124NavigationalWarning.From(dataset, out var diagnostics);

var msi = warning.Preamble?.MessageSeriesIdentifier;
Console.WriteLine($"Warning {msi?.WarningNumber}/{msi?.Year} ({msi?.ProductionAgency})");
Console.WriteLine($"  Area: {warning.Preamble?.GeneralArea}");

foreach (var part in warning.Parts)
{
    Console.WriteLine($"  Part {part.Id}: restriction {part.Restriction}");
    Console.WriteLine($"    {part.WarningInformation}");
    foreach (var area in part.AffectedAreas)
        Console.WriteLine($"    affected area {area.Id} ({area.GeometryKind})");
}

foreach (var d in diagnostics) Console.WriteLine(d);

Validation

The EncDotNet.S100.Datasets.S124.Validation namespace provides a pack of normative rules built on the EncDotNet.S100.Validation framework. Rule identifiers follow the convention S124-R-{clause}, traceable back to the S-124 (Edition 1.0.0) Feature Catalogue or to S-100 Part 10b for shared encoding constraints.

using EncDotNet.S100.Datasets.S124;
using EncDotNet.S100.Datasets.S124.DataModel;
using EncDotNet.S100.Datasets.S124.Validation;

var dataset = S124Dataset.Open("navwarn.gml");
var warning = S124NavigationalWarning.From(dataset, out _);

var report = S124NavigationalWarningRules.Validate(warning);
foreach (var finding in report.Findings)
    Console.WriteLine($"[{finding.Severity}] {finding.RuleId}: {finding.Message}");

The default rule set covers eight Tier-1/Tier-2 rules:

Rule Description
S124-R-1.1 A navigational warning must contain at least one NavwarnPart.
S124-R-2.1 Every navigational warning must include a NavwarnPreamble.
S124-R-2.2 messageSeriesIdentifier must carry a positive warning number and a plausible year.
S124-R-3.1 NAVAREA must be one of the IMO NAVAREA codes (I…XXI).
S124-R-4.1 All coordinates must lie within the WGS-84 lat/lon ranges.
S124-R-4.2 Surface exterior rings must be closed and contain at least four positions.
S124-R-5.1 Each NavwarnPart must carry non-empty warning text.
S124-R-6.1 A References information type that sets referenceCategory must include messageReference.

Tier-3 cross-dataset rules (e.g. resolving the referenced warning of a cancellation against a sibling catalogue) are out of scope for this pack.

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