This is the fourth in a series of blog posts aimed at documenting the development of an XCRI-CAP 1.2 validator. The entire series can be found by visiting the validator blog post list. My aim is to post a new blog post every week until the development is complete, then at least once every month to document both the usage of the validator as well as any community-highlighted modifications or issues.

One item that has come up during the development of both the XCRI-CAP 1.2 validator and aggregator is vocabularies.  Using vocabularies for elements such as subject (optionally along with an xsi:type attribute) allows consumers of the feeds to understand the context of the information when it's imported.  Whilst vocabularies vary according to target audience, some vocabularies such as JACS are highly-used within the UK educational sector.  It is highly likely that groups involved in the latest - and any future - JISC-funded activity around XCRI will use vocabularies such as JACS in their feeds.

In order to ensure that the validator can handle vocabularies, it has been decided to write a module enabling validation of content using IMS VDEX files.  To achieve this, a VDEXValidator class has been created that can be used to select elements from the XCRI-CAP 1.2 document and validate them against a specific VDEX file.  If any of the information doesn't match the expected vocabulary, feedback can be highlighted to the user in the standard manner.  [Please note that VDEX files will be used to validate vocabularies using the online validator but VDEX files are not required to use vocabularies within the XCRI-CAP standard itself.]

To test this, the <studyMode> element from the XCRI-CAP 1.2 standard has been converted to VDEX format and the validation rules have been updated to use this VDEX file rather than having the values hard-coded within the validation module itself.  The process has also started for other enumerated values within the XCRI-CAP standard (attendancePattern, attendanceMode, etc), as well as other vocabularies such as JACS.

If you are implementing an XCRI-CAP 1.2 feed on behalf of your institution and would like more information on the recommended vocabularies to use, please contact the working and support groups on the XCRI forum.

The XCRI-CAP 1.2 validation library and an online tool to validate feeds are expected to be completed by the end of February 2012.