Linking website, web services, … using URL¶

This section applies mainly to ISO19139 records and partially to Dublin Core (ie. only documents can be associated in Dublin Core) standards.

Linking a document¶

2 approaches can be used to link documents:

by providing a URL
by uploading a document

To add a new one, click on the + caret button then Add an online resource button or, if alreay one exists, just click on the title of the Online resources.

To link a URL, set the following properties:

Protocol to describe the type of document attached (Web address (URL) is the default)
Linkage to point to the target document. It can be any type of links like http://, ftp://, file:///, …
Name is optional and provides a label for making an hyperlink
Description is optional and provides more details about the link

To upload a document, switch to the Upload tab and choose a document, or drag and drop it in the pop up. In that case, the protocol is hidden and is set to WWW:DOWNLOAD.

Depending on your needs, more specific links could be added and will be associated to different actions and display in the applications.

Linking a WMS layer¶

To be able to view a record on the map viewer, it may be relevant to add a reference to one or more WMS services publishing the dataset. An online resource is encoded using the following in ISO19139:

<gmd:onLine xmlns:gmd="http://www.isotc211.org/2005/gmd"
            xmlns:gco="http://www.isotc211.org/2005/gco">
   <gmd:CI_OnlineResource>
      <gmd:linkage>
         <gmd:URL>https://download.data.grandlyon.com/wms/grandlyon</gmd:URL>
      </gmd:linkage>
      <gmd:protocol>
         <gco:CharacterString>OGC:WMS</gco:CharacterString>
      </gmd:protocol>
      <gmd:name>
         <gco:CharacterString>cad_cadastre.cadsubdivisionsection</gco:CharacterString>
      </gmd:name>
      <gmd:description>
         <gco:CharacterString>Subdivision de section cadastrale (Plan cadastral informatisé du Grand Lyon)(OGC:WMS)</gco:CharacterString>
      </gmd:description>
   </gmd:CI_OnlineResource>
</gmd:onLine>

To add a WMS layer:

choose the protocol OGC:WMS Web Map Service,
set the URL of the service,
then the wizzard query the service to retrieve the list of layers
choose one or more layer in the list or set it manually.

Linking a database table or a GIS file on the network¶

To reference a GIS file or a database table, user can upload or link to a that resource (see Linking a document). The type of protocol depends on the type of resource associated:

Type of resource	Vector file uploaded (eg. zipped Shapefile)
URL	File URL created after upload on the catalog. eg. http://localhost:8080/geonetwork/srv/eng/resources.get?id=1631&fname=CCM.zip&access=private
Protocol	WWW:DOWNLOAD
Name	File name (readonly)

Type of resource	Vector file on the network
URL	File path. eg. file:///shared/geodata/world/hydrology/rivers.shp
Protocol	FILE:GEO or FILE:RASTER
Name	File description

Type of resource	Vector (Table PostGIS)
URL	jdbc:postgresql://localhost:5432/login:password@db
Protocol	DB:POSTGIS
Name	Table name

When having information about the database or file on the local network, it may be relevant to hide those informations for public users (see Restricting information to metadata sections).

Linking data using ATOM feeds¶

If your organisation provides ATOM feeds to facilitate access to the data, metadate records can link to these feeds. Users can link to a service feed in a service record and to a dataset feed in a dataset record.

<gmd:MD_DigitalTransferOptions>
 <gmd:onLine>
  <gmd:CI_OnlineResource>
   <gmd:linkage>
    <gmd:URL>http://www.broinspireservices.nl/atom/awp.atom</gmd:URL>
   </gmd:linkage>
   <gmd:protocol>
    <gco:CharacterString>INSPIRE Atom</gco:CharacterString>
   </gmd:protocol>
   <gmd:name>
    <gco:CharacterString>gdn.Aardwarmtepotentie</gco:CharacterString>
   </gmd:name>
  </gmd:CI_OnlineResource>
 </gmd:onLine>
</gmd:MD_DigitalTransferOptions>

Once registered in the metadata, the ATOM feed will be displayed on the record view:

../../../../_images/atom-choose-feed.png

Users can choose a service, the list of datasets available are retrieved and the download links displayed to the user. A dataset feed can have one or more downloads:

../../../../_images/atom-choose-dataset.png

Examples:

NGR National Georegister, Statistics Netherlands Land Use 2015 ATOM

The catalog also provides the capability to produce ATOM feeds for services and datasets from metadata records. To enable this, check the ATOM API (see OpenSearch and INSPIRE ATOM). A GML dataset can be exposed using the following encoding in order to be published in a dataset ATOM feed:

<gmd:transferOptions>
   <gmd:MD_DigitalTransferOptions>
      <gmd:unitsOfDistribution>
         <gco:CharacterString>B</gco:CharacterString>
      </gmd:unitsOfDistribution>
      <gmd:transferSize>
         <gco:Real>428973180</gco:Real>
      </gmd:transferSize>
      <gmd:onLine>
         <gmd:CI_OnlineResource>
            <gmd:linkage>
               <gmd:URL>https://download.data.public.lu/resources/inspire-annex-i-theme-addresses-addresses/20191118-115245/ad.address.gml</gmd:URL>
            </gmd:linkage>
            <gmd:protocol>
               <gco:CharacterString>WWW:DOWNLOAD-1.0-http--download</gco:CharacterString>
            </gmd:protocol>
            <gmd:applicationProfile>
               <gco:CharacterString>INSPIRE-Download-Atom</gco:CharacterString>
            </gmd:applicationProfile>
            <gmd:name>
               <gmx:MimeFileType type="application/octet-stream">AD.Address.gml</gmx:MimeFileType>
            </gmd:name>
            <gmd:description>
               <gco:CharacterString></gco:CharacterString>
            </gmd:description>
            <gmd:function>
               <gmd:CI_OnLineFunctionCode codeList="http://standards.iso.org/ittf/PubliclyAvailableStandards/ISO_19139_Schemas/resources/codelist/ML_gmxCodelists.xml#CI_OnLineFunctionCode"
                                          codeListValue="download">download</gmd:CI_OnLineFunctionCode>
            </gmd:function>
         </gmd:CI_OnlineResource>
      </gmd:onLine>
   </gmd:MD_DigitalTransferOptions>
</gmd:transferOptions>

Examples:

INSPIRE Portal of the Grand-Duchy of Luxembourg / INSPIRE - Annex I Theme Addresses - Addresses

Reference documents:

INSPIRE technical guidelines for download services.