[ckan-dev] dcat_to_ckan

[Friedrich Lindenberg]

Hi Adria,

the mapper is using a subclass of Graph (also called Graph, kill me)
that you will get by importing from dcat.core. As a very simple
example, see https://bitbucket.org/okfn/dcat-tools/src/0ec5012bf12a/dcat/tests/mapper.py
for basic usage.

The second parameter is the dataset URI, so the typical usage for the
script would be to run in a look over all dcat:Datasets in the given
graph.

- Friedrich

2011/5/25 Adrià Mercader <amercadero at gmail.com>:
> Hi Friedrich,
> Two questions regardind the dcat_to_ckan mapper:
> * What is the second parameter (dataset) supposed to be?
> * I got an exception when I try to execute it (full traceback at the end):
> AttributeError: 'Graph' object has no attribute 'bound_query'
>
> Here is the code I'm using
>
>         from ckanext.pdeu.dcat.core.mapper import dcat_to_ckan
>         from rdflib.graph import Graph
>         try: from cStringIO import StringIO
>         except ImportError: from StringIO import StringIO
>
>         # harvest_object.content is the content from
> http://www.opengov.se/data/1/rdf/, stored in the database
>         graph = Graph()
>         graph.parse(StringIO(harvest_object.content)
>         dcat_to_ckan(graph,'http://test/')
>
> Any clues of what might be happening?
>
> Thanks,
> Adrià
>
>
>
> Traceback (most recent call last):
>  File "/home/adria/dev/envs/ckan/bin/paster", line 8, in <module>
>    load_entry_point('PasteScript==1.7.3', 'console_scripts', 'paster')()
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/paste/script/command.py",
> line 84, in run
>    invoke(command, command_name, options, args[1:])
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/paste/script/command.py",
> line 123, in invoke
>    exit_code = runner.run(args)
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/paste/script/command.py",
> line 218, in run
>    result = self.command()
>  File "/home/adria/dev/envs/ckan/src/ckanext-harvest/ckanext/harvest/commands/harvester.py",
> line 89, in command
>    consumer.wait()
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/carrot/messaging.py",
> line 446, in wait
>    it.next()
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/carrot/backends/pyamqplib.py",
> line 300, in consume
>    self.channel.wait()
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/amqplib/client_0_8/abstract_channel.py",
> line 107, in wait
>    return amqp_method(self, args, content)
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/amqplib/client_0_8/channel.py",
> line 1973, in _basic_deliver
>    func(msg)
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/carrot/messaging.py",
> line 291, in _receive_callback
>    self.receive(message.payload, message)
>  File "/home/adria/dev/envs/ckan/lib/python2.6/site-packages/carrot/messaging.py",
> line 344, in receive
>    callback(message_data, message)
>  File "/home/adria/dev/envs/ckan/src/ckanext-harvest/ckanext/harvest/queue.py",
> line 136, in fetch_callback
>    harvester.import_stage(obj)
>  File "/home/adria/dev/envs/ckan/src/ckanext-pdeu/ckanext/pdeu/harvesters.py",
> line 371, in import_stage
>    dcat_to_ckan(graph,'http://test/234234')
>  File "/home/adria/dev/envs/ckan/src/ckanext-pdeu/ckanext/pdeu/dcat/core/mapper.py",
> line 52, in dcat_to_ckan
>    data['name'] = first(_query("?dataset dc:identifier ?out"))
>  File "/home/adria/dev/envs/ckan/src/ckanext-pdeu/ckanext/pdeu/dcat/core/mapper.py",
> line 27, in first
>    for x in _q:
>  File "/home/adria/dev/envs/ckan/src/ckanext-pdeu/ckanext/pdeu/dcat/core/mapper.py",
> line 17, in _query
>    for row in graph.bound_query("SELECT DISTINCT ?out WHERE {%s}" % fragment,
> AttributeError: 'Graph' object has no attribute 'bound_query'
>