Hi Antonio, thanks for answering!
The easiest thing for me would be using a python script that reads the data
from the database and modifies the xml (ex. using lxml library,
https://lxml.de/).
Would namespaces be used similarly to this simple example? I just added a
test node 'mycustomfield' to a thredds catalog dataset entry.
<catalog version="1.0.1><service ..... />
<dataset name="WRF Domain-03 2018-03-23T00:00:00"
ID="testWRF/2018/20180319_00/wrfout_d03_2018-03-23_00:00:00"
urlPath="WRF/2018/20180319_00/wrfout_d03_2018-03-23_00:00:00"><dataSize
units="Mbytes">137.2</dataSize><date type="modified">2018-06-28T10:
27:07Z</date><timeCoverage><start>2018-03-23T00:00:00</start><duration>6
hours</duration></timeCoverage><myns:mycustomfield xmlns:myns="myurl">My
custom stuff</myns:mycustomfield></dataset>
</catalog>
Regarding the catalog: I can't modify single datasets in the catalog.xml
because it only contains the datasetscan. Some metadata can be added for
all entries at the datasetscan level, but others are specific (ex. if the
specific file was archived or not, and when). Is it possible to enable
something that writes the catalog in a temp file of some kind? What do you
mean by: "catalog entries generated by datasetScan are created in-memory
and they are cached/persisted (???) In specific storage format."? If it's
cached, I should be able to retrieve it somehow.
As for the dynamic catalog, the documentation says *'Dynamic catalogs are
generated by DatasetScan
<https://www.unidata.ucar.edu/software/thredds/current/tds/reference/DatasetScan.html>
elements, at the time the user request is made. These catalogs are not
cached'* so, it I understood correctly, I can't create a text file out of
it and modify it.
Thanks,
Chiara
On 19 July 2018 at 14:47, Antonio S. Cofino <cofinoa@xxxxxxxxx> wrote:
> Hola Chiara,
>
> To "enrich" the TDS catalog you can use XML namespaces [1]. That allows to
> use more than one XML schema.
>
> In fact the TDS already uses it for the datasetScan to point using XLink
> schema to the directories been scanned.
>
> With respect to the datasetScan feature to create a proxy of an absolute
> latest atomic dataset, it would require to create an new datasetScan
> element.
>
> Meanwhile you can create/modify the catalogs using an external tool.
>
> I would recommend use a tool/library which is XML "aware" to guarantee
> well formed and semantically correct XML documents, but using other tool
> would fit your purpose.
>
> Take into account that catalog entries generated by datasetScan are
> created in-memory and they are cached/persisted (???) In specific storage
> format.
>
> One interesting feature in the TDS5.0 version are the dynamic catalogs,
> similar to a catalogScan. But it has not been officially released but the
> current beta version already implements it.
>
> Antonio S. Cofino
>
>
> [1] https://www.w3schools.com/xml/xml_namespaces.asp
>
>
>
> On 19 Jul 2018 12:37, "Chiara Scaini" <saetachiara@xxxxxxxxx> wrote:
>
> Hi all, I'm setting up a thredds catalog to be used by Geonetwork.
>
> The catalog contains meteorological data, but will be enriched by other
> data sources (ex. a table containing the list of records that were moved to
> a backup facility and are no longer available on disk, or a table
> containing pictures related to the files).
>
> Is it possible to enrich the xml file with other data (ex. inserting xml
> nodes directly into the file) without breaking thredds functionalities?
> What strategy do you recommend (ex. a bash script to modify the xml,
> or...?).
>
> Note that I'm using a <datasetScan> to recursively get all items in a
> nested folder structure, so I would like to modify the 'real' xml catalog
> that contains all the nodes (some information should to be inserted at the
> container level, others at the data level).
>
> Many thanks,
> Chiara
>
>
>
> --
> Chiara Scaini
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--
Chiara Scaini
