Constraints in the Information Model

Discussion of current Constraints

See also the discussion of Constraints in the ODRL Vocabulary

Legend:

• Text highlighted in green: the current specification in http://w3c.github.io/poe/model/#infoModel
• Text highlighted in amber: proposed new specification/definition/comment ...
• (? : an internal issue to be solved

Constraint related definitions in the Information Model

• 3.4 Permission
  • Constraint: the Permission MAY refer to one or more Constraints which affect the validity of the Permission, e.g. if the Action play is only permitted for a certain period of time (OPTIONAL)
  • Constraint: the Permission MAY refer to one or more Constraints which affect the validity of the Permission: it only becomes effective if all of the referred Constraints are true.(OPTIONAL) Example: the Action play is only permitted for a certain period of time

• 3.5 Prohibition
  • Constraint: the Prohibition MAY refer to one or more Constraint entities (OPTIONAL)
  • Constraint: the Prohibition MAY refer to one or more Constraints which affect the validity of the Prohibition: it only becomes effective if all of the referred Constraints are true.(OPTIONAL) Example: the Action display is only prohibited for a certain country.

• 3.6 Duty
  • Constraint: a Duty MAY link to one or more Constraints (OPTIONAL)
  • Constraint: the Duty MAY refer to one or more Constraints which affect the fulfillment of the Duty: it is only fulfilled if all of the referred Constraints are true.(OPTIONAL) Example: the Duty Action payAmount is only fulfilled if a specific amount is paid.

• 3.8 Constraint
  • The Constraint entity indicates limits and restrictions to the Permission, the Prohibition and the Duty entity. Constraints express mathematical terms with two operands and one operator.
  • The Constraint entity indicates limits and restrictions to the Permission, the Prohibition and the Duty entity. Constraints express a rule for comparing two operands by one operator. If the two operands match the result of the constraint is TRUE.
  • The name identifies the left operand of the mathematical operation for the Constraint such as “Number of Usages” and “Expiration Date” etc.
  • The name identifies the left operand of the logic operation for the Constraint, it SHOULD include the entity it constrains and how its value for a comparison has to be retrieved/generated. It MAY include the data type of the value and it MAY include references to resources for retrieving/generating the value.
  • The section “When processing …” may be turned into an example or be omitted.
  • (? is there a chance to put the left operand identifier into a property named accordingly? The use of “name” is misleading and may cause confusion by people not familiar with ODRL. //michaelS)