Maps metadata and DataHub

I post this message in order to express some needs about the way a peculiar kind of resources, maps for instance, may be used by one of the GeoNetwork-UI apps : DataHub. One of my customers (Région Hauts-de-France) intend to deploy this software as the frontend for its catalogue of maps (digital maps not hard copy maps).

Map is a type of resource that one can reference in GeoNetwork for a long time but in a way that is far from being ideal when ISO19115 is used for the metadata model: this standard assumes a map is just a kind of dataset. The only specific property that may be used to clearly indicate a resource is a map is “presentationForm” with “mapDigital” and “mapHardcopy” values.

The distinction between static and interactive maps is done by GeoNetwork during indexation by analyzing some other properties (distributionFormat and transferOptions for instance): see core-geonetwork/schemas/iso19139/src/main/plugin/iso19139/index-fields/index.xsl at main · geonetwork/core-geonetwork · GitHub. The rules used there are quite outdated, especially the use of OGC:OWS-C and OGC:WMC: they were discussed in 2013 (see #1250 (ISO19139 / Improve support for making metadata on maps) – GeoNetwork opensource Developer website).

As of GeoNetwork 4.4.6 (see Map / Save your map improvements by fxprunayre · Pull Request #8155 · geonetwork/core-geonetwork · GitHub), maps are not treated any more at the same time as datasets and maps (which was the case before this release). They are now indexed as maps even if their hierarchy level is “dataset”. This is fine for me (I imagine a map is not a dataset for most users).

In the first version of the DataHub, only resources tagged as datasets were available in search results. I don’t know if it is still the case. I hope this is not the case anymore or, at least, this will change soon in order to be able to find maps in the DataHub search results (since maps are no longer datasets in the Elasticsearch index).

This would be great if, during the next codesprint, the way maps described using ISO19115 metadata model could be discussed in order that they could be handled properly by the DataHub.

Thank you very much.

[my apologies for the quality of my English - no AI used to produce it]

Hi!

Good news, this is indeed a topic that we will tackle in the code sprint next week. See: geonetwork‐ui codesprint 28‐30 January 2025 · geonetwork/core-geonetwork Wiki · GitHub

IGN is funding the initial effort on this, i.e. supporting both “service” and “reuse” records in the Datahub (maps are included in the “reuse” concept). This also brings many new questions to the Datahub UX which we at Camptocamp are currently actively working on.

One of the things that we will do in the code sprint is also clarify the road map to make apparent upcoming features and save you the trouble of asking such questions.

Hope that helps!

Interesting. Thank you very much.

If the “reuse” concept can be handled by ISO19115 records and indexed by GeoNetwork as maps this would be great.

I know that interactive maps are described quite differently by the Prodige suite: they are described as invoke services due to INSPIRE related reasons.

Have a great codesprint.

I have to say that for now we don’t really plan any specific things for interactive maps. Reuse records will essentially have a title/description/contact and one to many links to anything that relies on datasets in the catalog.

We might later on come up with a system that shows an interactive map right in the Datahub, but for that we need to find a standard more sturdy than what OWS-C has become, so this is still very much an open question.

Thank you for your interest, and stay tuned for more updated during the codesprint!

I did not mean to display the interactive maps in the DataHub. The main needs: display the metadata of the map (if the metadata describes a map) : textual fields, links, pictures… (the usual suspects).

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Hi Benjamin,

Thanks for the inputs.
The Datahub will support other resource type than “dataset”, it will probably be configurable in the settings.

Therefore, it means that the record page should be specific for all kinds of resources. If you contribute the support for map resources, which is much appreciated, it would be great to provide some mockups on how you will represent this page, what informations are you going to put inside (eg. a interactive map or just a link). We have to be strict on the design and be sure that it’s aligned with the Datahub spirit.

To come back to the original discussion about maps, what is a map in your case ? A context ? A link to an application (eg Mapstore) ? Something else ?

Note that I am confused with the informations that you give, looking at some metadata, the hierarchy level was hardcode as maps, there are not dataset (see DataGrandEst example below), therefore we don’t need to do regexp on WMS or WMC things.

Now, I see that there is also an application type, dunno what’s the difference with interactive map though.
:man_shrugging:

Ref

The Datahub will support other resource type than “dataset”, it will probably be configurable in the settings.

Nice.

Therefore, it means that the record page should be specific for all kinds of resources. If you contribute the support for map resources, which is much appreciated, it would be great to provide some mockups on how you will represent this page, what informations are you going to put inside (eg. a interactive map or just a link).

From ISO19115 point of view a map is supposed to be a kind of dataset. At first glance, we do not need something much specific in the DataHub to deal with maps. The same metadata model seems to apply. We just need that the DataHub accepts to display metadata for maps. Knowing the discribed resource is a map is the job of the GeoNetwork index. A second step could be to display map metadata records in a specific way but it does not seem to be necessary.

We have to be strict on the design and be sure that it’s aligned with the Datahub spirit.

Fair enough.

To come back to the original discussion about maps, what is a map in your case ? A context ? A link to an application (eg Mapstore) ? Something else ?

For my customer:

  • static maps are just regular document files containing a map (PNG, PDF files for instance). Their metadata contain links to web pages or links to downloadable resources.
  • interactive maps are web mapping applications (MapStore, mviewer…). Their metadata contain links to the web pages hosting these applications.

Note that I am confused with the informations that you give, looking at some metadata, the hierarchy level was hardcode as maps, there are not dataset (see DataGrandEst example below), therefore we don’t need to do regexp on WMS or WMC things.
. Interactive map
. Static map

These metadata records are from DataGrandEst. They use their own metadata editor which is not GeoNetwork and they do not use the DataHub yet. I have not analysed their stock of map metadata records. I do no want to comment them here and now.

The needs I point out (the way maps are dealt by GeoNetwork and DataHub) comes from another of my customers: Région Hauts-de-France. So, please, do not rely on what is done by DataGrandEst.

therefore we don’t need to do regexp on WMS or WMC things

Hum, today, that’s the way interactive maps are detected by the default indexation process of GeoNetwork (presence of WMC or OWS-C related online resource). This could eventually be changed if it is not appropriate (it is not, in my humble opinion).

there are not dataset

Don’t forget :

  • from ISO19115 point of view: a map is a dataset
  • the template for map metadata available in GeoNetwork do have a “dataset” value for the hierarchyLevel field
  • before GeoNetwork 4.4.6 a map could indexed as a dataset and a map.

Now, I see that there is also an application type, dunno what’s the difference with interactive map though.

We see a lot of ways to describe a map even using a well established international standard. Examples of map metadata records from another catalogue:

I think we do need to think of maps carefully and not introduce to many specific mechanisms to handle them in the DataHub application. Before specifying what a map is from a DataHub perspective it would be great to have a much larger consensus on how to describe them with ISO19115 (or other schemas).

Thank you for this interesting recap!

Map metadata is indeed not a simple subject. A thing to keep in mind is that the Datahub app relies exclusively on the GeoNetwork index when it comes to interpreting metadata. So if the index says “this is a map”, then the Datahub will assume it is.

The topic will become a little bit more involved once we implement reading/writing metadata in XML, because then we’ll have to write some logic in GeoNetwork-UI to decide how to encode a map record.

I agree that we shouldn’t do anything too specific. The direction in GeoNetwork-UI so far has been 1/ support as many versions of GeoNetwork as possible and 2/ stick to the standards as much as possible (i.e. do not reproduce the GeoNetwork historical idiosyncracies).

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