Changes between Version 4 and Version 5 of CMDI 1.2/Cues/Derived values

Timestamp:

12/02/13 14:40:29 (11 years ago)

Author:

twagoo

Comment:

--

CMDI 1.2/Cues/Derived values

@@ -9 +9 @@
 Most metadata needs to be created manually but in some cases parts of it can be derived: either from the described resource (e.g. a lot of technical metadata: file size, encoding, bit rate, ...) or from other metadata values (e.g. language code -> language name), sometimes in combination with external data (age can be derived from the combination of date of birth (metadata) and the current date (external information)).
 
-The actual derivation of values has to be carried out by the tool (i.e. the editor), obviously, but the logic will be largely profile or component specific. Therefore a unified method of specifying relations between metadata fields and resources, other metadata fields or 'environmental' values is needed, not unlike the display rules described in [[CMDI 1.2/Cues/Display information|Extended display information]]. An obvious way of representing these rules would be by means of something ''like'' RDF triples to indicate that the value of (element/resource/...) X provides a value for element Y if transformed in way T. The editor would then interpret these rules and apply them where applicable.
+The actual derivation of values has to be carried out by the tool (i.e. the editor), obviously, but the logic will be largely profile or component specific. Therefore a unified method of specifying relations between metadata fields and resources, other metadata fields or 'environmental' values is needed, not unlike the display rules proposed for [[CMDI 1.2/Cues/Display information|extended display information]]. 
+An obvious way of representing these rules would be by means of something ''like'' RDF triples to indicate that the value of (element/resource/...) X provides a value for element Y if transformed in way T. The editor would then interpret these rules and apply them where applicable.
 
 Examples of rules that might be supported:
 * !CreationDate gets populated with the current date (format yyyy-mm-dd)
 * !FileSize gets populated with the file size in bytes of the referenced resource
-* !LanguageName gets filled in based on the value of LanguageCode and an external lookup table
-* The value of Actor.Age becomes the difference between the current data and the value of Actor.DateOfBirth in years (floored)
+* !LanguageName gets filled in based on the value of !LanguageCode and an external lookup table
+* The value of Actor.Age becomes the difference between the current data and the value of Actor.!DateOfBirth in years (floored)
 * ....
 These examples illustrate the possibilities but also the potential complexity of such a rule based system.