diff --git a/README.md b/README.md index b8d9cce5..02a0aa13 100644 --- a/README.md +++ b/README.md @@ -5,1242 +5,37 @@ [![Code Coverage](http://codecov.io/github/ckan/ckanext-dcat/coverage.svg?branch=master)](http://codecov.io/github/ckan/ckanext-dcat?branch=master) -This extension provides plugins that allow CKAN to expose its metadata and consume metadata from other catalogs using RDF documents serialized using DCAT. The Data Catalog Vocabulary (DCAT) is "an RDF vocabulary designed to facilitate interoperability between data catalogs published on the Web". More information can be found on the following W3C page: +Ckanext-dcat is a [CKAN](https://github.com/ckan/ckan) extension that helps data publishers expose and consume metadata as serialized RDF documents using [DCAT](https://github.com/ckan/ckan). -[http://www.w3.org/TR/vocab-dcat](http://www.w3.org/TR/vocab-dcat) -It also offers other features related to Semantic Data like exposing the necessary markup to get your datasets indexed in [Google Dataset Search](https://toolbox.google.com/datasetsearch). +> [!IMPORTANT] +> Read the documentation for a full user guide: +> https://docs.ckan.org/projects/ckanext-dcat -Check the [overview](#overview) section for a summary of the available features. - - -## Contents - - - -- [Overview](#overview) -- [Installation](#installation) -- [Schemas](#schemas) - * [Compatibility with existing profiles](#compatibility-with-existing-profiles) -- [RDF DCAT endpoints](#rdf-dcat-endpoints) - * [Dataset endpoints](#dataset-endpoints) - * [Catalog endpoint](#catalog-endpoint) - * [URIs](#uris) - * [Content negotiation](#content-negotiation) -- [RDF DCAT harvester](#rdf-dcat-harvester) - * [Maximum file size](#maximum-file-size) - * [Transitive harvesting](#transitive-harvesting) - * [Extending the RDF harvester](#extending-the-rdf-harvester) -- [JSON DCAT harvester](#json-dcat-harvester) -- [RDF DCAT to CKAN dataset mapping](#rdf-dcat-to-ckan-dataset-mapping) - * [Custom fields](#custom-fields) - * [URIs](#uris-1) - * [Lists](#lists) - * [Contact points and Publisher](#contact-points-and-publisher) - * [Spatial coverage](#spatial-coverage) - * [Licenses](#licenses) -- [RDF DCAT Parser](#rdf-dcat-parser) -- [RDF DCAT Serializer](#rdf-dcat-serializer) - * [Inherit license from the dataset as fallback in distributions](#inherit-license-from-the-dataset-as-fallback-in-distributions) -- [Profiles](#profiles) - * [Writing custom profiles](#writing-custom-profiles) - * [Command line interface](#command-line-interface) - * [Compatibility mode](#compatibility-mode) -- [XML DCAT harvester (deprecated)](#xml-dcat-harvester-deprecated) -- [Translation of fields](#translation-of-fields) -- [Structured data and Google Dataset Search indexing](#structured-data-and-google-dataset-search-indexing) -- [CLI](#cli) -- [Configuration reference](#configuration-reference) -- [Running the Tests](#running-the-tests) -- [Releases](#releases) -- [Acknowledgements](#acknowledgements) -- [Copying and License](#copying-and-license) - - ## Overview -[DCAT](http://www.w3.org/TR/vocab-dcat) has become the basis for many metadata sharing standards, like DCAT-AP and DCAT-US for data portals in Europe and the USA respectively. This extension aims to provide tools and guidance to allow publishers to publish and share DCAT based metadata easily. - In terms of CKAN features, this extension offers: -* [Pre-built CKAN schemas](#schemas) for common Application Profiles that can be adapted to each site requirement to provide out-of-the -box DCAT support in data portals. +* [Pre-built CKAN schemas](https://docs.ckan.org/projects/ckanext-dcat/en/latest/getting-started#schemas) for common Application Profiles that can be adapted to each site requirements to provide out-of-the-box DCAT support in data portals, including tailored form fields, validation etc. (currently supporting DCAT AP v1, v2, and v3). -* [RDF DCAT Endpoints](#rdf-dcat-endpoints) that expose the catalog's datasets in different RDF serializations (`dcat` plugin). +* [DCAT Endpoints](https://docs.ckan.org/projects/ckanext-dcat/en/latest/endpoints) that expose the catalog datasets in different RDF serializations (`dcat` plugin). -* An [RDF Harvester](#rdf-dcat-harvester) that allows importing RDF serializations from other catalogs to create CKAN datasets (`dcat_rdf_harvester` plugin). +* An [RDF Harvester](https://docs.ckan.org/projects/ckanext-dcat/en/latest/harvester) that allows importing RDF serializations from other catalogs to create CKAN datasets (`dcat_rdf_harvester` plugin). -* An [JSON DCAT Harvester](#json-dcat-harvester) that allows importing JSON objects that are based on DCAT terms but are not defined as JSON-LD, using the serialization described in the [spec.dataportals.org](http://spec.dataportals.org/#datasets-serialization-format) site (`dcat_json_harvester` plugin).. +* Other features like [Command Line Interface](https://docs.ckan.org/projects/ckanext-dcat/en/latest/cli) or support for indexing in [Google Dataset Search](https://docs.ckan.org/projects/ckanext-dcat/en/latest/google-dataset-search). These are implemented internally using: -* A base [mapping](#rdf-dcat-to-ckan-dataset-mapping) between DCAT and CKAN datasets and viceversa (compatible with [DCAT-AP v1.1](https://joinup.ec.europa.eu/asset/dcat_application_profile/asset_release/dcat-ap-v11) and [DCAT-AP v2.1](https://joinup.ec.europa.eu/collection/semantic-interoperability-community-semic/solution/dcat-application-profile-data-portals-europe/release/210)). - -* An [RDF Parser](#rdf-dcat-parser) that allows to read RDF serializations in different formats and extract CKAN dataset dicts, using customizable [profiles](#profiles). - -* An [RDF Serializer](#rdf-dcat-serializer) that allows to transform CKAN datasets metadata to different semantic formats, also allowing customizable [profiles](#profiles). - - - -## Installation - - -1. Install the extension on your virtualenv: - - (pyenv) $ pip install -e git+https://github.com/ckan/ckanext-dcat.git#egg=ckanext-dcat - -2. Install the extension requirements: - - (pyenv) $ pip install -r ckanext-dcat/requirements.txt - -3. Enable the required plugins in your ini file: - - ckan.plugins = dcat dcat_rdf_harvester structured_data - -4. To use the pre-built schemas, install [ckanext-scheming](https://github.com/ckan/ckanext-scheming): - - pip install -e "git+https://github.com/ckan/ckanext-scheming.git#egg=ckanext-scheming" - -Check the [Schemas](#schemas) section for extra configuration needed. - -Optionally, if you want to use the RDF harvester, install ckanext-harvest as well ([https://github.com/ckan/ckanext-harvest#installation](https://github.com/ckan/ckanext-harvest#installation)). - -For further configuration options available, see [Configuration reference](#configuration-reference). - - - - -## Schemas - -The extension includes ready to use [ckanext-scheming](https://github.com/ckan/ckanext-scheming) schemas that enable DCAT support. These include a schema definition file (located in `ckanext/dcat/schemas`) plus extra validators and other custom logic that integrates the metadata modifications with the RDF DCAT [Parsers](#rdf-dcat-parser) and [Serializers](#rdf-dcat-serializer) and other CKAN features and extensions. - -There are the following schemas currently included with the extension: - -* *dcat_ap_recommended.yaml*: Includes the recommended properties for `dcat:Dataset` and `dcat:Distribution` according to the DCAT AP specification. You can use this schema with the `euro_dcat_ap_2` (+ `euro_dcat_ap_scheming`) and `euro_dcat_ap_3` profiles. -* *dcat_ap_full.yaml*: Includes most of the properties defined for `dcat:Dataset` and `dcat:Distribution` in the [DCAT AP 2.1](https://semiceu.github.io/DCAT-AP/releases/2.1.1/) and [DCAT AP v3](https://semiceu.github.io/DCAT-AP/releases/3.0.0/) specification. You can use this schema with the `euro_dcat_ap_2` (+ `euro_dcat_ap_scheming`) and `euro_dcat_ap_3` profiles. - -Most sites will want to use these as a base to create their own custom schema to address their own requirements, perhaps alongside a [custom profile](#writing-custom-profiles). Of course site maintainers can add or remove schema fields, as well as change the existing validators. - -In any case, the schema file used should be defined in the configuration file, alongside these configuration options: - - # Make sure to add scheming_datasets after the dcat plugin - ckan.plugins = activity dcat [...] scheming_datasets - - # Point to one of the defaults or your own version of the schema file - scheming.dataset_schemas = ckanext.dcat.schemas:dcat_ap_2.1_recommended.yaml - - # Include the dcat presets as well as the standard scheming ones - scheming.presets = ckanext.scheming:presets.json ckanext.dcat.schemas:presets.yaml - - # Sites using the euro_dcat_ap and euro_dcat_ap_2 profiles must add the - # euro_dcat_ap_scheming profile if they want to use ckanext-scheming schemas (see next section) - ckanext.dcat.rdf.profiles = euro_dcat_ap_2 euro_dcat_ap_scheming - -### Compatibility with existing profiles - -Sites using the existing `euro_dcat_ap` and `euro_dcat_ap_2` profiles should not see any change in their -current parsing and serialization functionalities and these profiles will not change their outputs going -forward (unless a bug is being fixed). Sites willing to migrate to a scheming based metadata schema can do -so by adding the `euro_dcat_ap_scheming` profile at the end of their profile chain (e.g. -`ckanext.dcat.rdf.profiles = euro_dcat_ap_2 euro_dcat_ap_scheming`), which will modify the existing profile -outputs to the expected format by the scheming validators. - -Note that the scheming profile will only affect fields defined in the schema definition file, so sites can start migrating gradually different metadata fields. - - - -## RDF DCAT endpoints - -By default when the `dcat` plugin is enabled, the following RDF endpoints are available on your CKAN instance. The schema used on the serializations can be customized using [profiles](#profiles). - -To disable the RDF endpoints, you can set the following config in your ini file: - - ckanext.dcat.enable_rdf_endpoints = False - - -### Dataset endpoints - -RDF representations of a particular dataset can accessed using the following endpoint: - - https://{ckan-instance-host}/dataset/{dataset-id}.{format} - -The extension will determine the RDF serialization format returned. The currently supported values are: - -| Extension | Format | Media Type | -|-----------|-------------------------------------------------------------|---------------------| -| `xml` | [RDF/XML](https://en.wikipedia.org/wiki/RDF/XML) | application/rdf+xml | -| `ttl` | [Turtle](https://en.wikipedia.org/wiki/Turtle_%28syntax%29) | text/turtle | -| `n3` | [Notation3](https://en.wikipedia.org/wiki/Notation3) | text/n3 | -| `jsonld` | [JSON-LD](http://json-ld.org/) | application/ld+json | - -The fallback `rdf` format defaults to RDF/XML. - -Here's an example of the different formats: - -* https://opendata.swiss/en/dataset/verbreitung-der-steinbockkolonien.rdf -* https://opendata.swiss/en/dataset/verbreitung-der-steinbockkolonien.xml -* https://opendata.swiss/en/dataset/verbreitung-der-steinbockkolonien.ttl -* https://opendata.swiss/en/dataset/verbreitung-der-steinbockkolonien.n3 -* https://opendata.swiss/en/dataset/verbreitung-der-steinbockkolonien.jsonld - -RDF representations will be advertised using `` tags on the `` sectionon the dataset page source code, eg: - - - - - - - - - - -Check the [RDF DCAT Serializer](#rdf-dcat-serializer) section for more details about how these are generated and how to customize the output using [profiles](#profiles). - - -You can specify the profile by using the `profiles=,` query parameter on the dataset endpoint (as a comma-separated list): - -* https://opendata.swiss/en/dataset/verbreitung-der-steinbockkolonien.xml?profiles=euro_dcat_ap -* https://opendata.swiss/en/dataset/verbreitung-der-steinbockkolonien.jsonld?profiles=schemaorg - -*Note*: When using this plugin, the above endpoints will replace the old deprecated ones that were part of CKAN core. - - -### Catalog endpoint - -Additionally to the individual dataset representations, the extension also offers a catalog-wide endpoint for retrieving multiple datasets at the same time (the datasets are paginated, see below for details): - - https://{ckan-instance-host}/catalog.{format}?[page={page}]&[modified_since={date}]&[profiles={profile1},{profile2}]&[q={query}]&[fq={filter query}] - -This endpoint can be customized if necessary using the `ckanext.dcat.catalog_endpoint` configuration option, eg: - - ckanext.dcat.catalog_endpoint = /dcat/catalog/{_format} - -The custom endpoint **must** start with a forward slash (`/`) and contain the `{_format}` placeholder. - -As described previously, the extension will determine the RDF serialization format returned. - -* http://demo.ckan.org/catalog.rdf -* http://demo.ckan.org/catalog.xml -* http://demo.ckan.org/catalog.ttl - -RDF representations will be advertised using `` tags on the `` sectionon the homepage and the dataset search page source code, eg: - - - - - - - - - - - -The number of datasets returned is limited. The response will include paging info, serialized using the [Hydra](http://www.w3.org/ns/hydra/spec/latest/core/) vocabulary. The different terms are self-explanatory, and can be used by clients to iterate the catalog: - - @prefix hydra: . - - a hydra:PagedCollection ; - hydra:first "http://example.com/catalog.ttl?page=1" ; - hydra:last "http://example.com/catalog.ttl?page=3" ; - hydra:next "http://example.com/catalog.ttl?page=2" ; - hydra:totalItems 283 . - -The default number of datasets returned (100) can be modified by CKAN site maintainers using the following configuration option on your ini file: - - ckanext.dcat.datasets_per_page = 20 - -The catalog endpoint also supports a `modified_since` parameter to restrict datasets to those modified from a certain date. The parameter value should be a valid ISO-8601 date: - -http://demo.ckan.org/catalog.xml?modified_since=2015-07-24 - -It's possible to specify the profile(s) to use for the serialization using the `profiles` parameter: - -http://demo.ckan.org/catalog.xml?profiles=euro_dcat_ap,sweden_dcat_ap - -To filter the output, the catalog endpoint supports the `q` and `fq` parameters to specify a [search query](https://lucene.apache.org/solr/guide/6_6/the-dismax-query-parser.html#TheDisMaxQueryParser-TheqParameter) or [filter query](https://lucene.apache.org/solr/guide/6_6/common-query-parameters.html#CommonQueryParameters-Thefq_FilterQuery_Parameter): - -http://demo.ckan.org/catalog.xml?q=budget -http://demo.ckan.org/catalog.xml?fq=tags:economy - - - -### URIs - -Whenever possible, URIs are generated for the relevant entities. To try to generate them, the extension will use the first found of the following for each entity: - -* Catalog: - - `ckanext.dcat.base_uri` configuration option value. This is the recommended approach. Value should be a valid URI - - `ckan.site_url` configuration option value. - - 'http://' + `app_instance_uuid` configuration option value. This is not recommended, and a warning log message will be shown. - -* Dataset: - - The value of the `uri` field (note that this is not included in the default CKAN schema) - - The value of an extra with key `uri` - - Catalog URI (see above) + '/dataset/' + `id` field - -* Resource: - - The value of the `uri` field (note that this is not included in the default CKAN schema) - - Catalog URI (see above) + '/dataset/' + `package_id` field + '/resource/ + `id` field - -Note that if you are using the [RDF DCAT harvester](#rdf-dcat-harvester) to import datasets from other catalogs and these define a proper URI for each dataset or resource, these will be stored as `uri` fields in your instance, and thus used when generating serializations for them. - - -### Content negotiation - -The extension supports returning different representations of the datasets based on the value of the `Accept` header ([Content negotiation](https://en.wikipedia.org/wiki/Content_negotiation)). - -When enabled, client applications can request a particular format via the `Accept` header on requests to the main dataset page, eg: - - curl https://{ckan-instance-host}/dataset/{dataset-id} -H Accept:text/turtle - - curl https://{ckan-instance-host}/dataset/{dataset-id} -H Accept:"application/rdf+xml; q=1.0, application/ld+json; q=0.6" - -This is also supported on the [catalog endpoint](#catalog-endpoint), in this case when making a request to the CKAN root URL (home page). This won't support the pagination and filter parameters: - - curl https://{ckan-instance-host} -H Accept:text/turtle - -Note that this feature overrides the CKAN core home page and dataset page controllers, so you probably don't want to enable it if your own extension is also doing it. - -To enable content negotiation, set the following configuration option on your ini file: - - ckanext.dcat.enable_content_negotiation = True - - -## RDF DCAT harvester - -The RDF parser described in the previous section has been integrated into a harvester, -to allow automatic import of datasets from remote sources. To enable the RDF harvester, add the `dcat_rdf_harvester` plugin to your CKAN configuration file: - - ckan.plugins = ... dcat_rdf_harvester - -The harvester will download the remote file, extract all datasets using the parser and create or update actual CKAN datasets based on that. -It will also handle deletions, ie if a dataset is not present any more in the DCAT dump anymore it will get deleted from CKAN. - -The harvester will look at the `content-type` HTTP header field to determine the used RDF format. Any format understood by the [RDFLib](https://rdflib.readthedocs.org/en/stable/plugin_parsers.html) library can be parsed. It is possible to override this functionality and provide a specific format using the harvester configuration. This is useful when the server does not return the correct `content-type` or when harvesting a file on the local file system without a proper extension. The harvester configuration is a JSON object that you fill into the harvester configuration form field. - - {"rdf_format":"text/turtle"} - -*TODO*: configure profiles. - -### Maximum file size - -The default max size of the file (for each HTTP response) to harvest is actually 50 MB. The size can be customised by setting the configuration option `ckanext.dcat.max_file_size` to your CKAN configuration file. -Here‘s an example of setting the max file size to 100 MB: - -`ckanext.dcat.max_file_size = 100` - -### Transitive harvesting - -In transitive harvesting (i.e., when you harvest a catalog A, and a catalog X harvests your catalog), you may want to provide the original catalog info for each harvested dataset. - -By setting the configuration option `ckanext.dcat.expose_subcatalogs = True` in your ini file, you'll enable the storing and publication of the source catalog for each harvested dataset. - -The information contained in the harvested `dcat:Catalog` node will be stored as extras into the harvested datasets. -When serializing, your Catalog will expose the harvested Catalog using the `dct:hasPart` relation. This means that your catalog will have this structure: -- `dcat:Catalog` (represents your current catalog) - - `dcat:dataset` (1..n, the dataset created withing your catalog) - - `dct:hasPart` - - `dcat:Catalog` (info of one of the harvested catalogs) - - `dcat:dataset` (dataset in the harvested catalog) - - `dct:hasPart` - - `dcat:Catalog` (info of one of another harvester catalog) - ... - - -### Extending the RDF harvester - -The DCAT RDF harvester has extension points that allow to modify its behaviour from other extensions. These can be used by extensions implementing -the `IDCATRDFHarvester` interface. Right now it provides the following methods: - -* `before_download` and `after_download`: called just before and after retrieving the remote file, and can be used for instance to validate the contents. -* `update_session`: called before making the remote requests to update the `requests` session object, useful to add additional headers or for setting client certificates. Check the [`requests` documentation](http://docs.python-requests.org/en/master/user/advanced/#session-objects) for details. -* `before_create` / `after_create`: called before and after the `package_create` action has been performed -* `before_update` / `after_update`: called before and after the `package_update` action has been performed -* `after_parsing`: Called just after the content from the remote RDF file has been parsed - -To know more about these methods, please check the source of [`ckanext-dcat/ckanext/dcat/interfaces.py`](https://github.com/ckan/ckanext-dcat/blob/master/ckanext/dcat/interfaces.py). - -## JSON DCAT harvester - -The DCAT JSON harvester supports importing JSON objects that are based on DCAT terms but are not defined as JSON-LD. The exact format for these JSON files -is the one described in the [spec.dataportals.org](http://spec.dataportals.org/#datasets-serialization-format) site. There are [example files](https://github.com/ckan/ckanext-dcat/blob/master/examples/dataset.json) in the `examples` folder. - -To enable the JSON harvester, add the `dcat_json_harvester` plugin to your CKAN configuration file: - - ckan.plugins = ... dcat_json_harvester - -*TODO*: align the fields created by this harvester with the base mapping (ie the ones created by the RDF harvester). - -## RDF DCAT to CKAN dataset mapping - -The following table provides a generic mapping between the fields of the `dcat:Dataset` and `dcat:Distribution` classes and -their equivalents in the CKAN model. In most cases this mapping is deliberately a loose one. For instance, it does not try to link -the DCAT publisher property with a CKAN dataset author, maintainer or organization, as the link between them is not straight-forward -and may depend on a particular instance needs. When mapping from CKAN metadata to DCAT though, there are in some cases fallback fields -that are used if the default field is not present (see [RDF Serializer](#rdf-dcat-serializer) for more details on this. - -This mapping is compatible with the [DCAT-AP v1.1](https://joinup.ec.europa.eu/asset/dcat_application_profile/asset_release/dcat-ap-v11) and [DCAT-AP v2.1](https://joinup.ec.europa.eu/collection/semantic-interoperability-community-semic/solution/dcat-application-profile-data-portals-europe/release/210). It depends on the active profile(s) (see [Profiles](#profiles)) which DCAT properties are mapped. - -Sites are encouraged to use ckanext-scheming to manage their metadata schema (see [Schemas](#schemas) for all details). This changes in -some cases the way metadata is stored internally and presented at the CKAN API level, but should not affect the RDF DCAT output. - -| DCAT class | DCAT property | CKAN dataset field | CKAN fallback fields | Stored as | | -|-------------------|------------------------|-------------------------------------------|--------------------------------|-----------|---------------------------------------------------------------------------------------------------------------------------------------------------------------| -| dcat:Dataset | - | extra:uri | | text | See [URIs](#uris-1) | -| dcat:Dataset | dct:title | title | | text | | -| dcat:Dataset | dct:description | notes | | text | | -| dcat:Dataset | dcat:keyword | tags | | text | | -| dcat:Dataset | dcat:theme | extra:theme | | list | See [Lists](#lists) | -| dcat:Dataset | dct:identifier | extra:identifier | extra:guid, id | text | | -| dcat:Dataset | adms:identifier | extra:alternate_identifier | | text | | -| dcat:Dataset | dct:issued | extra:issued | metadata_created | text | | -| dcat:Dataset | dct:modified | extra:modified | metadata_modified | text | | -| dcat:Dataset | owl:versionInfo | version | extra:dcat_version | text | | -| dcat:Dataset | adms:versionNotes | extra:version_notes | | text | | -| dcat:Dataset | dct:language | extra:language | | list | See [Lists](#lists) | -| dcat:Dataset | dcat:landingPage | url | | text | | -| dcat:Dataset | dct:accrualPeriodicity | extra:frequency | | text | | -| dcat:Dataset | dct:conformsTo | extra:conforms_to | | list | See [Lists](#lists) | -| dcat:Dataset | dct:accessRights | extra:access_rights | | text | | -| dcat:Dataset | foaf:page | extra:documentation | | list | See [Lists](#lists) | -| dcat:Dataset | dct:provenance | extra:provenance | | text | | -| dcat:Dataset | dct:type | extra:dcat_type | | text | As of DCAT-AP v1.1 there's no controlled vocabulary for this field | -| dcat:Dataset | dct:hasVersion | extra:has_version | | list | See [Lists](#lists). It is assumed that these are one or more URIs referring to another dcat:Dataset | -| dcat:Dataset | dct:isVersionOf | extra:is_version_of | | list | See [Lists](#lists). It is assumed that these are one or more URIs referring to another dcat:Dataset | -| dcat:Dataset | dct:source | extra:source | | list | See [Lists](#lists). It is assumed that these are one or more URIs referring to another dcat:Dataset | -| dcat:Dataset | adms:sample | extra:sample | | list | See [Lists](#lists). It is assumed that these are one or more URIs referring to dcat:Distribution instances | -| dcat:Dataset | dct:spatial | extra:spatial_uri | | text | See [Spatial coverage](#spatial-coverage) | -| dcat:Dataset | dct:temporal | extra:temporal_start + extra:temporal_end | | text | None, one or both extras can be present | -| dcat:Dataset | dcat:temporalResolution| extra:temporal_resolution | | list | | -| dcat:Dataset | dcat:spatialResolutionInMeters| extra:spatial_resolution_in_meters | | list | | -| dcat:Dataset | dct:isReferencedBy | extra:is_referenced_by | | list | | -| dcat:Dataset | dct:publisher | extra:publisher_uri | | text | See [URIs](#uris-1) and [Publisher](#contact-points-and-publisher) | -| foaf:Agent | foaf:name | extra:publisher_name | | text | | -| foaf:Agent | foaf:mbox | extra:publisher_email | organization:title | text | | -| foaf:Agent | foaf:homepage | extra:publisher_url | | text | | -| foaf:Agent | dct:type | extra:publisher_type | | text | | -| dcat:Dataset | dcat:contactPoint | extra:contact_uri | | text | See [URIs](#uris-1) and [Contact points](#contact-points-and-publisher) | -| vcard:Kind | vcard:fn | extra:contact_name | maintainer, author | text | | -| vcard:Kind | vcard:hasEmail | extra:contact_email | maintainer_email, author_email | text | | -| dcat:Dataset | dcat:distribution | resources | | text | | -| dcat:Distribution | - | resource:uri | | text | See [URIs](#uris-1) | -| dcat:Distribution | dct:title | resource:name | | text | | -| dcat:Distribution | dcat:accessURL | resource:access_url | resource:url | text | If downloadURL is not present, accessURL will be used as resource url | -| dcat:Distribution | dcat:downloadURL | resource:download_url | | text | If present, downloadURL will be used as resource url | -| dcat:Distribution | dct:description | resource:description | | text | | -| dcat:Distribution | dcat:mediaType | resource:mimetype | | text | | -| dcat:Distribution | dct:format | resource:format | | text | | -| dcat:Distribution | dct:license | resource:license | | text | See [Licenses](#licenses) | -| dcat:Distribution | adms:status | resource:status | | text | | -| dcat:Distribution | dcat:byteSize | resource:size | | number | | -| dcat:Distribution | dct:issued | resource:issued | created | text | | -| dcat:Distribution | dct:modified | resource:modified | metadata_modified | text | | -| dcat:Distribution | dct:rights | resource:rights | | text | | -| dcat:Distribution | foaf:page | resource:documentation | | list | See [Lists](#lists) | -| dcat:Distribution | dct:language | resource:language | | list | See [Lists](#lists) | -| dcat:Distribution | dct:conformsTo | resource:conforms_to | | list | See [Lists](#lists) | -| dcat:Distribution | dcatap:availability | resource:availability | | text | | -| dcat:Distribution | dcat:compressFormat | resource:compress_format | | text | | -| dcat:Distribution | dcat:packageFormat | resource:package_format | | text | | -| dcat:Distribution | dcat:accessService | resource:access_services | | text | | -| dcat:DataService | dct:title | access_service:title | | text | | -| dcat:DataService | dcat:endpointURL | access_service:endpoint_url | | list | | -| dcat:DataService | dcat:endpointDescription| access_service:endpoint_description | | text | | -| dcat:DataService | dcatap:availability | access_service:availability | | text | | -| dcat:DataService | dcat:servesDataset | access_service:serves_dataset | | list | | -| dcat:DataService | dct:description | access_service:description | | text | | -| dcat:DataService | dct:license | access_service:license | | text | | -| dcat:DataService | dct:accessRights | access_service:access_rights | | text | | -| spdx:Checksum | spdx:checksumValue | resource:hash | | text | | -| spdx:Checksum | spdx:algorithm | resource:hash_algorithm | | text | | - -*Notes* - -### Custom fields - -Fields marked as `extra:` are stored as free form extras in the `euro_dcat_ap` and `euro_dcat_ap_2` profiles, -but stored as first level custom fields when using the scheming based profile (`euro_dcat_ap_scheming`), i.e: - - ```json - { - "name": "test_dataset_dcat", - "extras": [ - {"key": "version_notes", "value": "Some version notes"} - ] - } - ``` - - vs: - - ```json - { - "name": "test_dataset_dcat", - "version_notes": "Some version notes" - } - ``` - -### URIs - -Whenever possible, URIs are extracted and stored so there is a clear reference to the original RDF resource. -For instance: - - ```xml - - - - - Dataset 1 - - - Publishing Organization for dataset 1 - - - - - - ``` - - ```json - { - "title": "Dataset 1", - "extras": [ - {"key": "uri", "value": "http://data.some.org/catalog/datasets/1"}, - {"key": "publisher_uri", "value": "http://orgs.vocab.org/some-org"}, - {"key": "publisher_name", "value": "Publishing Organization for dataset 1"} - ] - } - ``` - - Another example: - - ``` - @prefix dcat: . - @prefix dct: . - @prefix rdf: . - - - a dcat:Dataset ; - dct:title "Dataset 1" ; - dcat:distribution - . - - - - a dcat:Distribution ; - dct:title "Distribution for dataset 1" ; - dcat:accessURL . - ``` - - ```json - { - "title": "Dataset 1", - "extras": [ - {"key": "uri", "value": "http://data.some.org/catalog/datasets/1"} - ], - "resources": [{ - "name": "Distribution for dataset 1", - "url": "http://data.some.org/catalog/datasets/1/downloads/1.csv", - "uri": "http://data.some.org/catalog/datasets/1/d/1" - }] - } - ``` - -### Lists - -On the legacy profiles, lists are stored as a JSON string, eg: - - ``` - @prefix dcat: . - @prefix dct: . - @prefix rdf: . - - - a dcat:Dataset ; - dct:title "Dataset 1" ; - dct:language "ca" , "en" , "es" ; - dcat:theme "http://eurovoc.europa.eu/100142" , "http://eurovoc.europa.eu/209065", "Earth Sciences" ; - ``` - - ```json - { - "title": "Dataset 1", - "extras": [ - {"key": "uri", "value": "http://data.some.org/catalog/datasets/1"} - {"key": "language", "value": "[\"ca\", \"en\", \"es\"]"} - {"key": "theme", "value": "[\"Earth Sciences\", \"http://eurovoc.europa.eu/209065\", \"http://eurovoc.europa.eu/100142\"]"} - ], - } - ``` - -On the scheming-based ones, these are shown as actual lists: - - ```json - { - "title": "Dataset 1", - "uri": "http://data.some.org/catalog/datasets/1"}, - "language": ["ca", "en", "es"] - "theme": ["Earth Sciences", "http://eurovoc.europa.eu/209065", "http://eurovoc.europa.eu/100142"] - } - ``` -### Contact points and Publisher - -Properties for `dcat:contactPoint` and `dct:publisher` are stored as namespaced extras in the legacy profiles. When using -a scheming-based profile, these are stored as proper objects (and multiple instances are allowed for contact point): - -```json -{ - "name": "test_dataset_dcat", - "title": "Test dataset DCAT", - "extras": [ - {"key":"contact_name","value":"PointofContact"}, - {"key":"contact_email","value":"contact@some.org"} - ], -} -``` - -vs: - -```json -{ - "name": "test_dataset_dcat", - "title": "Test dataset DCAT", - "contact": [ - { - "name": "Point of Contact 1", - "email": "contact1@some.org" - }, - { - "name": "Point of Contact 2", - "email": "contact2@some.org" - }, - ] -} -``` - -If no `publisher` or `publisher_*` fields are found, the serializers will fall back to getting the publisher properties from the organization the CKAN dataset belongs to. The organization schema can be customized with the schema located in `ckanext/dcat/schemas/publisher_organization.yaml` to provide the extra properties supported (this will additionally require loading the `scheming_organizations` plugin in `ckan.plugins`). - - -### Spatial coverage - - -The following formats for `dct:spatial` are supported by the default [parser](#rdf-dcat-parser). Note that the default [serializer](#rdf-dcat-serializer) will return the single `dct:spatial` instance form by default. - - - One `dct:spatial` instance, URI only - - ```xml - - ``` - - - One `dct:spatial` instance with text (this should not be used anyway) - - ```xml - Newark - ``` - - - One `dct:spatial` instance with label and/or geometry - - ```xml - - - - {"type": "Polygon", "coordinates": [[[175.0, 17.5], [-65.5, 17.5], [-65.5, 72.0], [175.0, 72.0], [175.0, 17.5]]]} - - - POLYGON ((175.0000 17.5000, -65.5000 17.5000, -65.5000 72.0000, 175.0000 72.0000, 175.0000 17.5000)) - - Newark - - - ``` - - - Multiple `dct:spatial` instances (as in GeoDCAT-AP) - - ```xml - - - - - {"type": "Polygon", "coordinates": [[[175.0, 17.5], [-65.5, 17.5], [-65.5, 72.0], [175.0, 72.0], [175.0, 17.5]]]} - - - POLYGON ((175.0000 17.5000, -65.5000 17.5000, -65.5000 72.0000, 175.0000 72.0000, 175.0000 17.5000)) - - - - - - Newark - - - ``` -If the RDF provides them, profiles should store the textual and geometric representation of the location in: - -* For legacy profiles in `spatial_text`, `spatial_bbox`, `spatial_centroid` or `spatial` (for any other geometries) extra fields -* For scheming-based profiles in objects in the `spatial_coverage` field, for instance: - -```json -{ - "name": "test_dataset_dcat", - "title": "Test dataset DCAT", - "spatial_coverage": [ - { - "geom": { - "type": "Polygon", - "coordinates": [...] - }, - "text": "Tarragona", - "uri": "https://sws.geonames.org/6361390/", - "bbox": { - "type": "Polygon", - "coordinates": [ - [ - [-2.1604, 42.7611], - [-2.0938, 42.7611], - [-2.0938, 42.7931], - [-2.1604, 42.7931], - [-2.1604, 42.7611], - ] - ], - }, - "centroid": {"type": "Point", "coordinates": [1.26639, 41.12386]}, - } - ] -} -``` - - -### Licenses - -On the CKAN model, license is at the dataset level whereas in DCAT model it - is at distributions level. By default the RDF parser will try to find a - distribution with a license that matches one of those registered in CKAN - and attach this license to the dataset. The first matching distribution's - license is used, meaning that any discrepancy accross distributions license - will not be accounted for. This behavior can be customized by overridding the - `_license` method on a custom profile. - - -## RDF DCAT Parser - -The `ckanext.dcat.processors.RDFParser` class allows to read RDF serializations in different -formats and extract CKAN dataset dicts. It will look for DCAT datasets and distributions -and create CKAN datasets and resources, as dictionaries that can be passed to [`package_create`](http://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.create.package_create) or [`package_update`](http://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.update.package_update). - -Here is a quick overview of how it works: - -```python - - from ckanext.dcat.processors import RDFParser, RDFParserException - - parser = RDFParser() - - # Parsing a local RDF/XML file - - with open('datasets.rdf', 'r') as f: - try: - parser.parse(f.read()) - - for dataset in parser.datasets(): - print('Got dataset with title {0}'.format(dataset['title']) - - except RDFParserException, e: - print ('Error parsing the RDF file: {0}'.format(e)) - - # Parsing a remote JSON-LD file - - import requests - - parser = RDFParser() - - content = requests.get('https://some.catalog.org/datasets.jsonld').content - - try: - parser.parse(content, _format='json-ld') - - for dataset in parser.datasets(): - print('Got dataset with title {0}'.format(dataset['title']) - - except RDFParserException, e: - print ('Error parsing the RDF file: {0}'.format(e)) - -``` - -The parser is implemented using [RDFLib](https://rdflib.readthedocs.org/), a Python library for working with RDF. Any -RDF serialization format supported by RDFLib can be parsed into CKAN datasets. The `examples` folder contains -serializations in different formats including RDF/XML, Turtle or JSON-LD. - -## RDF DCAT Serializer - -The `ckanext.dcat.processors.RDFSerializer` class generates RDF serializations in different -formats from CKAN dataset dicts, like the ones returned by [`package_show`](http://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.get.package_show) or [`package_search`](http://docs.ckan.org/en/latest/api/index.html#ckan.logic.action.get.package_search). - -Here is an example of how to use it: - -```python - - from ckanext.dcat.processors import RDFSerializer - - # Serializing a single dataset - - dataset = get_action('package_show')({}, {'id': 'my-dataset'}) - - serializer = RDFserializer() - - dataset_ttl = serializer.serialize_dataset(dataset, _format='turtle') - - - # Serializing the whole catalog (or rather part of it) - - datasets = get_action('package_search')({}, {'q': '*:*', 'rows': 50}) - - serializer = RDFserializer() - - catalog_xml = serializer.serialize_catalog({'title': 'My catalog'}, - dataset_dicts=datasets, - _format='xml') - - # Creating and RDFLib graph from a single dataset - - dataset = get_action('package_show')({}, {'id': 'my-dataset'}) - - serializer = RDFserializer() - - dataset_reference = serializer.graph_from_dataset(dataset) - - # serializer.g now contains the full dataset graph, an RDFLib Graph class - -``` - -The serializer uses customizable [profiles](#profiles) to generate an RDF graph (an [RDFLib Graph class](https://rdflib.readthedocs.org/en/latest/apidocs/rdflib.html#rdflib.graph.Graph)). -By default these use the [mapping](#rdf-dcat-to-ckan-dataset-mapping) described in the previous section. - -In some cases, if the default CKAN field that maps to a DCAT property is not present, some other fallback -values will be used instead. For instance, if the `contact_email` field is not found, `maintainer_email` -and `author_email` will be used (if present) for the email property of the `adms:contactPoint` property. - -Note that the serializer will look both for a first level field or an extra field with the same key, ie both -the following values will be used for `dct:accrualPeriodicity`: - - { - "name": "my-dataset", - "frequency": "monthly", - ... - } - - { - "name": "my-dataset", - "extras": [ - {"key": "frequency", "value": "monthly"}, - ] - ... - } - -Once the dataset graph has been obtained, this is serialized into a text format using [RDFLib](https://rdflib.readthedocs.org/), -so any format it supports can be obtained (common formats are 'xml', 'turtle' or 'json-ld'). - -### Inherit license from the dataset as fallback in distributions -It is possible to inherit the license from the dataset to the distributions, but only if there is no license defined in the resource yet. By default the license is not inherited from the dataset. This can be activated by setting the following parameter in the CKAN config file: - - ckanext.dcat.resource.inherit.license = True - - -## Profiles - -Both the parser and the serializer use profiles to allow customization of how the values defined in the RDF graph are mapped to CKAN and viceversa. - -Profiles define : - -* How the RDF graph values map into CKAN fields, ie how the RDF is parsed into CKAN datasets -* How CKAN fields map to an RDF graph, which can be then serialized -* How the CKAN catalog metadata maps to an RDF graph, which can be then serialized - -They essentially define the mapping between DCAT and CKAN. - -In most cases the default profile will provide a good mapping that will cover most properties described in the DCAT standard. If you want to extract extra fields defined in the RDF, are using a custom schema or -need custom logic, you can write a custom to profile that extends or replaces the default one. - -The profiles currently shipped with the extension are mostly based in the -[DCAT application profile for data portals in Europe](https://joinup.ec.europa.eu/asset/dcat_application_profile/description). As mentioned before though, they should be generic enough for most DCAT based representations. - -Sites that want to support a particular version of the DCAT-AP can enable a specific profile using one of the profiles below: - -* [DCAT-AP v3](https://semiceu.github.io/DCAT-AP/releases/3.0.0) (default): `euro_dcat_ap_3` -* [DCAT-AP v2.1.0](https://joinup.ec.europa.eu/collection/semantic-interoperability-community-semic/solution/dcat-application-profile-data-portals-europe/release/210): `euro_dcat_ap_2` -* [DCAT-AP v1.1.1](https://joinup.ec.europa.eu/asset/dcat_application_profile/asset_release/dcat-ap-v11): `euro_dcat_ap` - -This plugin also contains a profile to serialize a CKAN dataset to a [schema.org Dataset](http://schema.org/Dataset) called `schemaorg`. This is especially useful to provide [JSON-LD structured data](#structured-data). - -To define which profiles to use you can: - -1. Set the [`ckanext.dcat.rdf.profiles`](configuration.md#ckanextdcatrdfprofiles) configuration option on your CKAN configuration file: - - ckanext.dcat.rdf.profiles = euro_dcat_ap sweden_dcat_ap - -2. When initializing a parser or serializer class, pass the profiles to be used as a parameter, eg: - -```python - - parser = RDFParser(profiles=['euro_dcat_ap', 'sweden_dcat_ap']) - - serializer = RDFSerializer(profiles=['euro_dcat_ap', 'sweden_dcat_ap']) -``` - -Note that in both cases the order in which you define them is important, as it will be the one that the profiles will be run on. - - -### Writing custom profiles - -Internally, profiles are classes that define a particular set of methods called during the parsing process. -For instance, the `parse_dataset` method is called on each DCAT dataset found when parsing an RDF file, and should return a CKAN dataset. -Conversely, the `graph_from_dataset` will be called when requesting an RDF representation for a dataset, and will need to generate the necessary RDF graph. - -Custom profiles should always extend the `ckanext.dcat.profiles.RDFProfile` class. This class has several helper -functions to make getting metadata from the RDF graph easier. These include helpers for getting fields for FOAF and VCard entities like the ones -used to define publishers or contact points. Check the source code of `ckanex.dcat.profiles.py` to see what is available. - -Profiles can extend other profiles to avoid repeating rules, or can be completely independent. - -The following example shows a complete example of a profile built on top of the European DCAT-AP profile (`euro_dcat_ap`): - -```python - - from rdflib.namespace import Namespace - from ckanext.dcat.profiles import RDFProfile - - DCT = Namespace("http://purl.org/dc/terms/") - - - class SwedishDCATAPProfile(RDFProfile): - ''' - An RDF profile for the Swedish DCAT-AP recommendation for data portals - - It requires the European DCAT-AP profile (`euro_dcat_ap`) - ''' - - def parse_dataset(self, dataset_dict, dataset_ref): - - # Spatial label - spatial = self._object(dataset_ref, DCT.spatial) - if spatial: - spatial_label = self.g.label(spatial) - if spatial_label: - dataset_dict['extras'].append({'key': 'spatial_text', - 'value': str(spatial_label)}) - - return dataset_dict - - def graph_from_dataset(self, dataset_dict, dataset_ref): - - g = self.g - - spatial_uri = self._get_dataset_value(dataset_dict, 'spatial_uri') - spatial_text = self._get_dataset_value(dataset_dict, 'spatial_text') - - if spatial_uri: - spatial_ref = URIRef(spatial_uri) - else: - spatial_ref = BNode() - - if spatial_text: - g.add((dataset_ref, DCT.spatial, spatial_ref)) - g.add((spatial_ref, RDF.type, DCT.Location)) - g.add((spatial_ref, RDFS.label, Literal(spatial_text))) -``` - -Note how the dataset dict is passed between profiles so it can be further tweaked. - -Extensions define their available profiles using the `ckan.rdf.profiles` in the `setup.py` file, as in this [example](https://github.com/ckan/ckanext-dcat/blob/cc5fcc7be0be62491301db719ce597aec7c684b0/setup.py#L37:L38) from this same extension: - - [ckan.rdf.profiles] - euro_dcat_ap=ckanext.dcat.profiles:EuropeanDCATAPProfile - euro_dcat_ap_2=ckanext.dcat.profiles:EuropeanDCATAP2Profile - schemaorg=ckanext.dcat.profiles:SchemaOrgProfile - -## XML DCAT harvester (deprecated) - -The old DCAT XML harvester (`dcat_xml_harvester`) is now deprecated, in favour of the [RDF harvester](#rdf-dcat-harvester). -Loading it on the ini file will result in an exception on startup. - -The XML serialization described in the [spec.datacatalogs.org](http://spec.datacatalogs.org/#datasets_serialization_format) site is a valid RDF/XML one, so changing the harvester should have no effect. There might be slight differences in the way CKAN fields are created though, check [Compatibility mode](#compatibility-mode) for more details. - -## Translation of fields - -The `dcat` plugin automatically translates the keys of the dcat fields used in the frontend. -This makes it very easy to display the fields in the current language. - -To disable this behavior, you can set the following config value in your ini file (default: True): - - ckanext.dcat.translate_keys = False - - -## Structured data and Google Dataset Search indexing - -There are plugins available to add [structured data](https://developers.google.com/search/docs/guides/intro-structured-data) to dataset pages to provide richer metadata for search engines crawling your site. One of the most well known is [Google Dataset Search](https://toolbox.google.com/datasetsearch). The `structured_data` plugin will add the necessary markup in order to get your datasets indexed by Google Dataset Search. This markup is a JSON-LD snippet that uses the [schema.org](https://schema.org) vocabulary to describe the dataset. - -To add [structured data](https://developers.google.com/search/docs/guides/intro-structured-data) to dataset pages, activate the `structured_data` and `dcat` plugins in your ini file: - - ckan.plugins = dcat structured_data - -By default this uses the `schemaorg` profile (see [profiles](#profiles)) to serialize the dataset to JSON-LD, which is then added to the dataset detail page. -To change the schema, you have to override the Jinja template block called `structured_data` in [`templates/package/read_base.html`](https://github.com/ckan/ckanext-dcat/blob/master/ckanext/dcat/templates/package/read_base.html) and call the template helper function with different parameters: - - {% block structured_data %} - - {% endblock %} - -Example output of structured data in JSON-LD: - - < ... > - - - - - -## CLI - -The `ckan dcat` command offers utilites to transform between DCAT RDF Serializations and CKAN datasets (`ckan dcat consume`) and -viceversa (`ckan dcat produce`). In both cases the input can be provided as a path to a file: - - ckan dcat consume -f ttl examples/dcat/dataset.ttl - - ckan dcat produce -f jsonld examples/ckan/ckan_datasets.json - -or be read from stdin: - - ckan dcat consume - - -The latter form allows chaininig commands for more complex metadata processing, e.g.: - - curl https://demo.ckan.org/api/action/package_search | jq .result.results | ckan dcat produce -f jsonld - - -For the full list of options check `ckan dcat consume --help` and `ckan dcat produce --help`. - -## Configuration reference - - - -### General settings - -#### ckanext.dcat.rdf.profiles - -Example: - -``` -ckanext.dcat.rdf.profiles = euro_dcat_ap_2 my_local_ap -``` - -Default value: `euro_dcat_ap_2` - -RDF profiles to use when parsing and serializing. See https://github.com/ckan/ckanext-dcat#profiles -for more details. - - -#### ckanext.dcat.translate_keys - -Default value: `True` - -If set to True, the plugin will automatically translate the keys of the DCAT -fields used in the frontend (at least those present in the `ckanext/dcat/i18n` -po files). - - -### Parsers / Serializers settings - -#### ckanext.dcat.output_spatial_format - -Default value: `wkt` - -Format to use for geometries when serializing RDF documents. The default is -recommended as is the format expected by GeoDCAT, alternatively you can -use `geojson` (or both, which will make SHACL validation fail) - - -#### ckanext.dcat.resource.inherit.license - -Default value: `False` - -If there is no license defined for a resource / distribution, inherit it from -the dataset. - - -#### ckanext.dcat.normalize_ckan_format - -Default value: `True` - -When true, the resource label will be tried to match against the standard -list of CKAN formats (https://github.com/ckan/ckan/blob/master/ckan/config/resource_formats.json) -This allows for instance to populate the CKAN resource format field -with a value that view plugins, etc will understand (`csv`, `xml`, etc.) - - -#### ckanext.dcat.clean_tags - -Default value: `False` - -Remove special characters from keywords (use the old munge_tag() CKAN function). -This is generally not needed. - - -### Endpoints settings - -#### ckanext.dcat.enable_rdf_endpoints - -Default value: `True` - -Whether to expose the catalog and dataset endpoints with the RDF DCAT -serializations. - -#### ckanext.dcat.base_uri - -Example: - -``` -https://my-site.org/uris/ -``` - -Base URI to use when generating URIs for all entities. It needs to be a valid URI value. - -#### ckanext.dcat.catalog_endpoint - -Example: - -``` -ckanext.dcat.catalog_endpoint = /dcat/catalog/{_format} -``` - -Default value: `/catalog.{_format}` - -Custom route for the catalog endpoint. It should start with `/` and include the -`{_format}` placeholder. - - -#### ckanext.dcat.datasets_per_page - -Default value: `100` - -Default number of datasets returned by the catalog endpoint. - - -#### ckanext.dcat.enable_content_negotiation - -Default value: `False` - -Enable content negotiation in the main catalog and dataset endpoints. Note that -setting this to True overrides the core `home.index` and `dataset.read` endpoints. - - -### Harvester settings - -#### ckanext.dcat.max_file_size - -Default value: `50` - -Maximum file size that will be downloaded for parsing by the harvesters - - -#### ckanext.dcat.expose_subcatalogs - -Default value: `False` - -Store information about the origin catalog when harvesting datasets. -See https://github.com/ckan/ckanext-dcat#transitive-harvesting for more details. - - -### Deprecated options (will be removed in future versions) - -#### ckanext.dcat.compatibility_mode - -Default value: `False` - -Whether to modify some fields to maintain compatibility with previous versions -of the ckanext-dcat parsers. - - -#### ckanext.dcat.json_endpoint +* A base [mapping](https://docs.ckan.org/projects/ckanext-dcat/en/latest/mapping) between DCAT and CKAN datasets and viceversa (compatible with [DCAT-AP v1.1](https://joinup.ec.europa.eu/asset/dcat_application_profile/asset_release/dcat-ap-v11), [DCAT-AP v2.1](https://joinup.ec.europa.eu/collection/semantic-interoperability-community-semic/solution/dcat-application-profile-data-portals-europe/release/210) and [DCAT-AP v3](https://semiceu.github.io/DCAT-AP/releases/3.0.0/)). -Default value: `/dcat.json` +* An [RDF Parser](https://docs.ckan.org/projects/ckanext-dcat/en/latest/profiles#rdf-dcat-parser) that allows to read RDF serializations in different formats and extract CKAN dataset dicts, using customizable [profiles](https://docs.ckan.org/projects/ckanext-dcat/en/latest/profiles#profiles). -Custom route to expose the legacy JSON endpoint +* An [RDF Serializer](https://docs.ckan.org/projects/ckanext-dcat/en/latest/profiles#rdf-dcat-serializer) that allows to transform CKAN datasets metadata to different semantic formats, also allowing customizable [profiles](https://docs.ckan.org/projects/ckanext-dcat/en/latest/profiles#profiles). - ## Running the Tests @@ -1259,7 +54,7 @@ To create a new release, follow these steps: ## Acknowledgements -Work on ckanext-dcat has been made possible by: +Work on ckanext-dcat has been made possible in part by: * the Government of Sweden and Vinnova, as part of work on [Öppnadata.se](http://oppnadata.se), the Swedish Open Data Portal. * [FIWARE](https://www.fiware.org), a project funded by the European Commission to integrate different technologies to offer connected cloud services from a single platform.