dependency rules between schema modules

[lzehl]

Essentials: core & controlledTerms
Extensions: all the others

Linking dimensions:

• property: required or optional
• relation: one-to-one or one-to-many
• selection: one type or multiple types (category)
• origin: same module, essential module and extension module

Categories scenarios:

• essential category: composed of schemas from essentials only
• extension category: composed of schemas from extensions only
• mixed category: composed of schemas from essentials and extensions

Dependency types:

• true: link between modules is by all means unavoidable
• soft: link between modules is avoidable
  • i: because property is optional
  • ii: selection from mixed category

Linking scenarios:

• property required, relation one-to-one or one-to-many with one type as selection:
  ✅ schema A truly depends on schema B within the same module
  ✅ schema A in core truly depends on schema B in controlledTerms
  ❌ schema A in core or controlledTerms truly depends on schema B in extension module
  ✅ schema A in extension truly depends on schema B in essential module
  ✅ schema A in extension 1 truly depends on schema B in extension 2 (okay but we need to define extension dependency tree)

• property required, relation one-to-one or one-to-many with category as selection:
  ✅ schema A truly depends on schemas B or C within the same module
  ✅ schema A in core truly depends on schemas B or C in controlledTerms
  ✅ schema A in extension truly depends on schema B or C in essential module
  ❌ schema A in core or controlledTerms truly depends on schema B or C in extension module(s)
  ✅ schema A in core or controlledTerms truly depends on schema B in core or controlledTerms and softly depends on schema C in extension module(s)

• property optional, relation one-to-one or one-to-many with one type or category as selection:
  ✅ schema A softly depends on schemas B (or C) within the same module
  ✅ schema A in core softly depends on schemas B (or C) in controlledTerms
  ✅ schema A in extension softly depends on schema B (or C) in essential module
  ⚫ schema A in core or controlledTerms softly depends on schema B (or C) in extension module(s)
  ✅ schema A in core or controlledTerms softly depends on schema B in core or controlledTerms, or schema C in extension module(s)

[lzehl]

Discussion Feedback on this setting:

-> rename true to hard

-> define soft.i (better: medium) and soft.ii (better: soft) with own names

• let's define that medium and hard should be treated in the same way; unless there is a strong justification to break that rule for medium

-> scenarios missing extension to extension rules (helpful to design a dependency tree/graph)

• all core and all extension modules should have at least one hard dependency to controlledTerms
• all extension modules should have at least one hard dependency to core
• if necessary, core can form soft dependencies with extension modules
• in extension modules we can differentiate between two types: activity based and others which might influence the logic of an extension dependency graph

-> mixed category: composed of schemas from essentials and extensions

• okay if extension schemas are in-depth options of the essential schemas as generic option; for example in-depth activity schemas as alternate in-depth option for generic protocol execution