Closed ajnelson-nist closed 2 years ago
When @eoghanscasey and I were discussing how to name these two properties, we had agreed between us to use the name found in the PDF specification. He had shown me PDF v1.7.
Per that specification, the name we should use is pdfCreationDate
, not pdfCreatedDate
. See e.g. Table 317 of this document:
https://opensource.adobe.com/dc-acrobat-sdk-docs/standards/pdfstandards/pdf/PDF32000_2008.pdf
found via the Library of Congress format page for PDF, Version 1.7, ISO 32000-1:2008.
CreationDate
appears in the PDF specification, not CreatedDate
. The implementation of the UCO property will use CreationDate
.
Background
UCO has the ability to represent certain timestamps based on sources like file systems or other metadata fields (e.g. from email). (See #420.) PDFs contain their own specialized timestamp fields, but UCO has no way of representing them yet.
The PDF specification provides for these time stamps:
Requirements
Requirement 1
UCO must be able to represent the internally embedded creation time of a PDF file.
Requirement 2
UCO must be able to represent the internally embedded modification time of a PDF file.
Requirement 3
UCO must be able to represent the internally embedded access time of a PDF file.
Risk / Benefit analysis
Benefits
UCO would improve its timeline capabilities by representing these times.
Risks
There is a name pattern discrepancy between UCO's current
observable:modifiedTime
andobservable:createdTime
, versus the names in the specification. One name pattern must be selected, or the PDF specification should be deferred to.Otherwise, this is an additive proposal.
Competencies demonstrated
Competency 1
Suppose a PDF is found to have both a creation and modification timestamp embedded.
Competency Question 1.1
Do the creation and modification time follow a sensible temporal ordering - modification occurs at or after creation time?
Ask for all PDF files in our knowledge base that have a creation time that comes definitively after the modification time.
Result 1.1
Solution suggestion
To the
observable:PDFFileFacet
observable:pdfCreatedDate
, cardinality 0..1, typexsd:dateTime
.observable:pdfModDate
, cardinality 0..1, typexsd:dateTime
.Coordination
develop