Metadata source map

This page explains how to read NGB.Metadata even when you start from runtime consumers rather than from every metadata type definition file.

Confirmed source anchors

NGB.Metadata/NGB.Metadata.csproj
NGB.Runtime/Documents/DocumentService.cs

What the project boundary tells you first

NGB.Metadata/NGB.Metadata.csproj is intentionally small.

It depends on:

• NGB.Tools
• NGB.Core

and nothing heavier.

That is a strong design signal: Metadata is a foundational descriptive model, not a runtime engine and not an infrastructure provider.

Why DocumentService is the best consumer-side anchor

NGB.Runtime/Documents/DocumentService.cs imports and uses metadata types from namespaces such as:

• NGB.Metadata.Base
• NGB.Metadata.Documents.Hybrid
• NGB.Metadata.Documents.Storage

The file consumes metadata types such as:

• document type metadata;
• table metadata;
• column metadata;
• list filter metadata;
• lookup-source metadata;
• mirrored document relationship metadata.

That makes DocumentService.cs the fastest way to understand what metadata is for.

What Metadata is responsible for

The module describes the shape of business artifacts without executing them.

In practical terms, metadata is where the platform models things like:

• which tables belong to a document or catalog;
• which columns exist and what types they have;
• which fields are required;
• which lookups a field uses;
• what the UI label/presentation hints are;
• which relationships are mirrored or special;
• which filters a list exposes.

What Metadata is not responsible for

Metadata should not:

• run posting logic;
• execute SQL;
• own runtime workflow decisions;
• materialize HTTP controllers;
• hide vertical business logic.

It describes. Other modules execute.

How to read Metadata through Runtime

In DocumentService.cs, watch these moments carefully:

• GetModel(...) — runtime resolves a document model from metadata;
• list query building — metadata-driven filters become runtime queries;
• payload parsing and validation — metadata drives required fields and type conversion;
• DTO/form/list shaping — metadata becomes UI-ready contract shape.

That is the clearest proof that metadata is the platform’s descriptive backbone.

Recommended reading order

1. NGB.Metadata/NGB.Metadata.csproj
2. NGB.Runtime/Documents/DocumentService.cs

Then, in your local checkout, continue directly into the metadata type definitions referenced by DocumentService.

Safe change rules for Metadata

Keep metadata declarative

Do not move orchestration or SQL behavior into metadata classes.

Keep metadata reusable across verticals

Avoid hard-wiring Property Management or Trade semantics into shared metadata types.

Favor explicit field/table descriptors

If Runtime needs to reason about a document or catalog shape, express that in metadata rather than in scattered special cases.