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Daniel Holloway wrote: > > John Caron wrote: > > > heres another strawman, incorporating our latest discussions: > > > > http://www.unidata.ucar.edu/projects/THREDDS/xml/InvCatalog.0.6d.dtd > > > > Recent changes: > > > > .... > > I've used the DTD listed above to create two examples of what > I believe I could return in an XML-based dods-dir response. The > catalogs represent simple directory representations of dods-accessible > data; level1.xml is a higher-level directory containing only subdirs > and level2.xml is one of the subdirs containing the dods-accessible > datafiles. > > Both of these files validate, I get some warnings but mostly > due to style issues, there are no errors. These examples represent > the minimum information that I could provide, there are ways I > could augment this service to provide some of the additional fields > represented in the DTD but this example is meant to illustrate a > minimum set. > > Points to note: > > 1: I'd need to provide 2 service elements, one for > type = DODS, and one for type = Other, where Other represents > the dods-dir service. In many cases there will be both datafiles > and subdirectories in a file system. Do I need to have two > service elements? If so, in the 'Level2.xml' example how do > I indicate which service to use without adding an explicit > access element for each dataset element? In each dataset element you can indicate the service it uses with the serviceName attribute; its value would be the same as the value of the service elements name attribute. > 2: I use 'collection' as a simple filesystem collection, there > may not be any meaningful relation between the files contained > in the directory other than they're accessible via the DODS DAP. > > 3: Am I using 'catalogRef' correctly? The intention is to > indicate another collection level that should only be traversed > at the user's request. catalogRef should reference a THREDDS catalog. Yours is referencing a dods-dir page. I've reworked and attached your examples (with fewer years in level1.xml and fewer example datasets in level2.1985.xml). 1) I changed the catalogRefs in level1.xml to point to the level2.*.xml files. 2) I added datasets in level1.xml that give access to the dods-dir pages. 3) I added a serviceName attribute in the dataset elements in the level2.*.xml files. A few alternatives: 1) You could have just one level. Each year could be a collection that contains the individual datasets. 2) Again, just one level. Each year is a dataset with the dods-dir access and contains sub-datasets for each individual dataset. I'm working on the THREDDS catalog generator tool. Currently I'm working on expanding DODS file servers into THREDDS catalogs. After I get that working I'd like to work on crawling dods-dir pages. So, I'll be wanting to pick your brains on this stuff. Ethan > Dan > > > > > 1) Collections as datasets. Ethan and I think the cleanest way to allow > > "collections as datasets" is to allow nested datasets. Collections remain > > just groups of datasets. A Collection as a dataset is done as a dataset with > > nested datasets. Nested dataset elements (Joe's meaning #2) should imply (in > > some way we need to clarify better) nested datasets (Joe's meaning #1 and > > #3). > > > > 2) allow compound services again. I have talked myself into that these will > > be often useful. > > > > 3) services are now contained within any collection, rather than having to > > be all in the top catalog element. They are scoped by the collection they > > are in (so we no longer use ID, since those are global). This makes a > > catalogRef have (almost) the same semantics as a collection. > > > > 4) a catalog now only has exactly one collection element. (i considered > > eliminating catalog but i think its better this way). > > > > 5) "attribute" changed to "property" (tired of saying "the attribute > > attribute") > > > > 6) access element can specify an absolute URL with a serverType -or- a > > reletive URL with a serverID. > > > > Unless I get a barrage of objections, I will document this in more detail > > ASAP. I will be gone for a week starting next Tuesdy, so Ethan will continue > > the conversation as needed. Hopefully, we can converge soon and take a > > break! I think I have incorporated all the good ideas i have heard in this > > discussion. Have I left out something, or do you think any feature is not > > worth the complexity? -- Ethan R. Davis Telephone: (303) 497-8155 Software Engineer Fax: (303) 497-8690 UCAR Unidata Program Center E-mail: edavis@xxxxxxxx P.O. Box 3000 Boulder, CO 80307-3000 http://www.unidata.ucar.edu/
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE catalog SYSTEM "http://www.unidata.ucar.edu/projects/THREDDS/xml/InvCatalog.0.6d.dtd";> <catalog name="htn_sst_decloud" version="0.6d"> <collection name="htn_sst_decloud/"> <service name="URI-DODS" serviceType="DODS" base="http://dods.gso.uri.edu/dods-3.2/nph-dods/"/> <service name="DODSdirectory" serviceType="Other" base="http://dods.gso.uri.edu/dods-3.2/nph-dods/"/> <dataset name="DODS_dir of htn_sst_decloud/1985/" serviceName="DODSdirectory"/> <catalogRef xlink:title="htn_sst_decloud/1985/" xlink:href="./level2.1985.xml"/> <dataset name="DODS_dir of htn_sst_decloud/1986/" serviceName="DODSdirectory"/> <catalogRef xlink:title="htn_sst_decloud/1986/" xlink:href="./level2.1986.xml"/> </collection> </catalog>
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE catalog SYSTEM "http://www.unidata.ucar.edu/projects/THREDDS/xml/InvCatalog.0.6d.dtd";> <catalog name="htn_sst_decloud/1985" version="0.6d"> <collection name="htn_sst_decloud/1985"> <service name="URI-DODS" serviceType="DODS" base="http://dods.gso.uri.edu/dods-3.2/nph-dods/"/> <service name="DODSDirectory" serviceType="Other" base="http://dods.gso.uri.edu/dods-3.2/nph-dods/"/> <dataset name="k85001182828.htn_d" serviceName="URI-DODS" urlPath="htn_sst_decloud/1985/k85001182828.htn_d.Z"/> <dataset name="k85001182828.htn_d" serviceName="URI-DODS" urlPath="htn_sst_decloud/1985/k85002181750.htn_d.Z"/> </collection> </catalog>
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