@startuml Requirements

/'
Diagram:     Requirements
DateCreate:  2019-03-06
Description: This diagram presents the model used to capture requirements, for use both in standards document markup,
and as standalone machine-readable artefacts.

History of changes:
> 2019-03-19: Added RequirementType/filename
> 2019-0-19: Added subsequence
> 2020-06-16: Added number
> 2020-06-16: Added keep-with-next
'/


'******* CLASS DEFINITION *********************************************

together {
class Requirement {
  + obligation: "requirement"
}

class Recommendation {
  + obligation: "recommendation"
}

class Permission {
  + obligation: "permission"
}
}

class RequirementType {
  + obligation: ObligationType[1..*],
  + id: String,
  + unnumbered: Boolean[0..1],
  + number: String[0..1],
  + subsequence: String[0..1],
  + keep-with-next: Boolean[0..1],
  + keep-lines-together: Boolean[0..1],
  + filename: String[0..1],
  + title: FormattedString[0..1],
  + label: String[0..1],
  + subject: String[0..1],
  + inherit: String[0..*],
  + model: String[0..1],
  + type: String[0..1],
  + classification: ClassificationType[0..*],
  + measurement-target: RequirementSubpart[0..*],
  + specification: RequirementSubpart[0..*],
  + verification: RequirementSubpart[0..*],
  + import: RequirementSubpart[0..*],
  + description: RequirementSubpart[0..*],
  + references: BibliographicItem[0..1],
  + subrequirement: RequirementType[0..*]
}

class RequirementSubpart {
  + type: String[0..1],
  + exclude: Boolean[0..1],
  + content: Block[1..*]
  + keep-with-next: Boolean[0..1],
  + keep-lines-together: Boolean[0..1],
}

class ClassificationType {
  + tag: String,
  + value: String
}

enum ObligationType <<enumeration>> {
  requirement
  recommendation
  permission
}

class BibliographicItem <<Bibliography>> {
}

class Block <<BasicDoc>> {
}

'******* NOTES ********************************************************
note left of RequirementType: RequirementType is a generic category,\nwhich is agnostic as to obligation.\nRequirement, Recommendation, Permission\nset a specific obligation, although this\ncan be overridden
note right of RequirementType: description, import, verification,\nmeasurement-target, references\ncan appear in any order.

'******* CLASS RELATIONS **********************************************
Requirement --down-|> RequirementType
Recommendation --down-|> RequirementType
Permission --down-|> RequirementType

RequirementType <-- ObligationType
RequirementType <-- ClassificationType
RequirementType <-- BibliographicItem
RequirementType <-- Block
RequirementType <-- RequirementSubpart

@enduml