Changes to Catalog version 1.0
last update: Jan 10, 2006
Changes for version 1.0.1
- The version attribute is "1.0.1" .
- The schema can be found here.
However, you should tell your parser to resolve to a local copy of it,
both for performance and to decouple with Unidata's web server.
Catalog base attribute
The optional attribute base can be added to the
catalog element to define a base URL. All relative URLs in the document
are interpreted against base URL. This follows the XML Base specification, which in turn references the specification of URIs.
DatasetType type
The dataset definition is now made in the DatasetType type, and catalogRef and datasetScan extend from it and are in the same substitution group. This means that you can use a catalogRef and datasetScan wherever a dataset is allowed. This simplifies the schema slightly. There are a few important effects of this:
- catalogRef now is-a dataset, and can have any and all metadata that a dataset can have.
- catalogRef must have a name attribute, since that is required on a dataset. The name is ignored, in favor of the xlink:title attribute. This is the only (slightly) backward incompatible change, and only affects validation.
metadata element
- process other namespaces with "lax" attribute, meaning validate if a schema can be found
timeCoverageType type
- some technical corrections to simplify the schema, no semantic changes.
variables element
- vocabulary attribute is now optional on a variables element
- vocabulary_name attribute is now optional on a variable element
- the variable element is now mixed content, meaning you can add text content, which is interpreted as a description of the variable.
Enumeration changes
All enumeration values should be tested case-insensitive.
- collectionTypes: add ForecastModelRuns
- dataTypes: add Point, Radial
- dataFormatTypes: add NEXRAD2, NIDS, GINI
- dateEnumTypes: add metadataCreated
Thredds Data Server
There are a number of changes and additions that are used only on the server.
dataset
- A dataset element can have a resourceControl attribute, that indicates that only users with permission for that resource can have access to the dataset.
- A datasetScan is a kind of dataset which contain other datasets which are found dynamically, e.g. by scanning directories. A datasetScan element looks like a catalogRef element on the client.
datasetRoot
- A datasetRoot element associates a URL path with a file directory on the server.
- A service element can have nested datasetRoot elements.
For tutorials on using these elements in the THREDDS Data Server see:
Other requests
- Allow a variable element to map to more than one vocabulary (Luca)
- Add last update time of the catalog, for caching. Could use HTTP headers. (Benno, LEAD).
- Extended inheritance across catalog references (Michael Burek)
Comments to THREDDS mailgroup or THREDDS support (put "THREDDS" in subject line)
Go to: THREDDS Tech Page or THREDDS Home Page 
