first implementation of OAIPMHReader (inveniosoftware#329)

* first implementation of OAIPMHReader * introduce a simple way to map OAI records to a dict without expecting a special metadata format. * fix installation requirements * fix tests * small fixes to make the tests run * add error handling * renamed oaipmh_scythe package * handle remarks/questions from review. * replaced access to a real OAI server with a mocking implementation. * Update invenio_vocabularies/datastreams/readers.py Co-authored-by: Pablo Tamarit <[email protected]> * Update tests/datastreams/test_datastreams.py Co-authored-by: Pablo Tamarit <[email protected]> * Moved reader tests to testreaders.py * add missing copyright in header --------- Co-authored-by: Pablo Tamarit <[email protected]>
caltechlibrary · Jun 10, 2024 · 87d7553 · 87d7553
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diff --git a/invenio_vocabularies/config.py b/invenio_vocabularies/config.py
@@ -17,6 +17,7 @@
     GzipReader,
     JsonLinesReader,
     JsonReader,
+    OAIPMHReader,
     TarReader,
     XMLReader,
     YamlReader,
@@ -111,6 +112,7 @@
     "yaml": YamlReader,
     "zip": ZipReader,
     "xml": XMLReader,
+    "oai-pmh": OAIPMHReader,
 }
 """Data Streams readers."""
 

diff --git a/invenio_vocabularies/datastreams/readers.py b/invenio_vocabularies/datastreams/readers.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) 2021-2024 CERN.
+# Copyright (C)      2024 University of Münster.
 #
 # Invenio-Vocabularies is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -19,7 +20,11 @@
 
 import requests
 import yaml
+from lxml import etree
 from lxml.html import parse as html_parse
+from oaipmh_scythe import Scythe
+from oaipmh_scythe.exceptions import NoRecordsMatch
+from oaipmh_scythe.models import Record
 
 from .errors import ReaderError
 from .xml import etree_to_dict
@@ -226,3 +231,81 @@ def _iter(self, fp, *args, **kwargs):
             raise ReaderError(f"Record not found in XML entry.")
 
         yield record
+
+
+class OAIPMHReader(BaseReader):
+    """OAIPMH reader."""
+
+    def __init__(
+        self,
+        *args,
+        base_url=None,
+        metadata_prefix=None,
+        set=None,
+        from_date=None,
+        until_date=None,
+        verb=None,
+        **kwargs,
+    ):
+        """Constructor."""
+        self._base_url = base_url
+        self._metadata_prefix = metadata_prefix if not None else "oai_dc"
+        self._set = set
+        self._until = until_date
+        self._from = from_date
+        self._verb = verb if not None else "ListRecords"
+        super().__init__(*args, **kwargs)
+
+    def _iter(self, scythe, *args, **kwargs):
+        """Read and parse an OAIPMH stream to dict."""
+        scythe.class_mapping["ListRecords"] = self.OAIRecord
+        try:
+            records = scythe.list_records(
+                from_=self._from,
+                until=self._until,
+                metadata_prefix=self._metadata_prefix,
+                set_=self._set,
+                ignore_deleted=True,
+            )
+            for record in records:
+                yield {"record": record}
+        except NoRecordsMatch:
+            raise ReaderError(f"No records found in OAI-PMH request.")
+
+    def read(self, item=None, *args, **kwargs):
+        """Reads from item or opens the file descriptor from origin."""
+        if item:
+            raise NotImplementedError(
+                "OAIPMHReader does not support being chained after another reader"
+            )
+        else:
+            with Scythe(self._base_url) as scythe:
+                yield from self._iter(scythe=scythe, *args, **kwargs)
+
+    class OAIRecord(Record):
+        """An XML unpacking implementation for more complicated formats."""
+
+        def get_metadata(self):
+            """Extract and return the record's metadata as a dictionary."""
+            return xml_to_dict(
+                self.xml.find(".//" + self._oai_namespace + "metadata").getchildren()[
+                    0
+                ],
+            )
+
+
+def xml_to_dict(tree: etree._Element):
+    """Convert an XML tree to a dictionary.
+
+    This function takes an XML element tree and converts it into a dictionary.
+
+    Args:
+        tree: The root element of the XML tree to be converted.
+
+    Returns:
+        A dictionary with the key "record".
+    """
+    dict_obj = dict()
+    dict_obj["record"] = etree.tostring(tree)
+
+    return dict_obj
diff --git a/setup.cfg b/setup.cfg
@@ -31,12 +31,14 @@ install_requires =
     invenio-records-resources>=6.0.0,<7.0.0
     lxml>=4.5.0
     PyYAML>=5.4.1
+    oaipmh-scythe @ git+https://github.com/ulbmuenster/invenio-oaipmh-scythe.git
 
 [options.extras_require]
 tests =
     pytest-black-ng>=0.4.0
     invenio-app>=1.4.0,<2.0.0
     invenio-db[postgresql,mysql]>=1.0.14,<2.0.0
+    pytest_httpserver>=1.0.10
     pytest-invenio>=2.1.0,<3.0.0
     Sphinx>=4.5
 elasticsearch7 =

diff --git a/tests/datastreams/test_readers.py b/tests/datastreams/test_readers.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) 2021-2024 CERN.
+# Copyright (C)      2024 University of Münster.
 #
 # Invenio-Vocabularies is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -16,8 +17,10 @@
 import pytest
 import yaml
 
+from invenio_vocabularies.datastreams.errors import ReaderError
 from invenio_vocabularies.datastreams.readers import (
     JsonReader,
+    OAIPMHReader,
     TarReader,
     YamlReader,
     ZipReader,
@@ -185,4 +188,134 @@ def test_json_element_reader(json_element_file, json_element):
     assert count == 1
 
 
+@pytest.fixture(scope="module")
+def oai_response_match():
+    response_data = """
+        <?xml version = "1.0" encoding = "UTF-8"?>
+        <OAI-PMH xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd" xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+            <responseDate>2024-05-29T13:20:04Z</responseDate>
+            <request metadataPrefix="MARC21plus-1-xml" set="authorities:sachbegriff" verb="ListRecords" from="2024-01-01T09:00:00Z" until="2024-01-01T17:00:00Z">https://services.dnb.de/oai/repository</request>
+            <ListRecords xsi:schemaLocation="http://www.loc.gov/MARC21/slim http://www.loc.gov/standards/marcxml/schema/MARC21slim.xsd">
+                <record>
+                    <header>
+                        <identifier>oai:dnb.de/authorities:sachbegriff/1074025261</identifier>
+                        <datestamp>2024-01-01T16:51:21Z</datestamp>
+                        <setSpec>authorities:sachbegriff</setSpec>
+                    </header>
+                    <metadata>
+                        <record type="Authority" xmlns="http://www.loc.gov/MARC21/slim">
+                            <leader>00000nz  a2200000nc 4500</leader>
+                            <controlfield tag="001">1074025261</controlfield>
+                            <controlfield tag="003">DE-101</controlfield>
+                            <controlfield tag="005">20240101175121.0</controlfield>
+                            <controlfield tag="008">150717n||azznnbabn           | ana    |c</controlfield>
+                            <datafield tag="024" ind1="7" ind2=" ">
+                                <subfield code="a">1074025261</subfield>
+                                <subfield code="0">http://d-nb.info/gnd/1074025261</subfield>
+                                <subfield code="2">gnd</subfield>
+                            </datafield>
+                            <datafield tag="035" ind1=" " ind2=" ">
+                                <subfield code="a">(DE-101)1074025261</subfield>
+                            </datafield>
+                            <datafield tag="035" ind1=" " ind2=" ">
+                                <subfield code="a">(DE-588)1074025261</subfield>
+                            </datafield>
+                            <datafield tag="040" ind1=" " ind2=" ">
+                                <subfield code="a">DE-12</subfield>
+                                <subfield code="c">DE-12</subfield>
+                                <subfield code="9">r:DE-384</subfield>
+                                <subfield code="b">ger</subfield>
+                                <subfield code="d">1210</subfield>
+                                <subfield code="f">rswk</subfield>
+                            </datafield>
+                            <datafield tag="042" ind1=" " ind2=" ">
+                                <subfield code="a">gnd1</subfield>
+                            </datafield>
+                            <datafield tag="065" ind1=" " ind2=" ">
+                                <subfield code="a">31.3b</subfield>
+                                <subfield code="2">sswd</subfield>
+                            </datafield>
+                            <datafield tag="075" ind1=" " ind2=" ">
+                                <subfield code="b">s</subfield>
+                                <subfield code="2">gndgen</subfield>
+                            </datafield>
+                            <datafield tag="075" ind1=" " ind2=" ">
+                                <subfield code="b">saz</subfield>
+                                <subfield code="2">gndspec</subfield>
+                            </datafield>
+                            <datafield tag="079" ind1=" " ind2=" ">
+                                <subfield code="a">g</subfield>
+                                <subfield code="q">s</subfield>
+                            </datafield>
+                            <datafield tag="150" ind1=" " ind2=" ">
+                                <subfield code="a">Rundbogenhalle</subfield>
+                            </datafield>
+                            <datafield tag="450" ind1=" " ind2=" ">
+                                <subfield code="a">Bogenhalle</subfield>
+                            </datafield>
+                            <datafield tag="550" ind1=" " ind2=" ">
+                                <subfield code="0">(DE-101)040230236</subfield>
+                                <subfield code="0">(DE-588)4023023-5</subfield>
+                                <subfield code="0">https://d-nb.info/gnd/4023023-5</subfield>
+                                <subfield code="a">Halle</subfield>
+                                <subfield code="4">obge</subfield>
+                                <subfield code="4">https://d-nb.info/standards/elementset/gnd#broaderTermGeneric</subfield>
+                                <subfield code="w">r</subfield>
+                                <subfield code="i">Oberbegriff generisch</subfield>
+                            </datafield>
+                            <datafield tag="670" ind1=" " ind2=" ">
+                                <subfield code="a">Stahlbetonbauwerke mit großer Spannweite, eingesetzt im Industriebau, z.b.Paketposthalle München; teilweise heute unter Denkmalschutz</subfield>
+                            </datafield>
+                        </record>
+                    </metadata>
+                </record>
+            </ ListRecords>
+        </OAI-PMH>
+    """
+    return response_data
+
+
+def test_oaipmh_reader(app, httpserver, oai_response_match):
+    httpserver.expect_request("/oai/repository").respond_with_data(
+        response_data=oai_response_match, mimetype="application/xml"
+    )
+    reader = OAIPMHReader(
+        base_url=httpserver.url_for("/oai/repository"),
+        metadata_prefix="MARC21plus-1-xml",
+        set="authorities:sachbegriff",
+        from_date="2024-01-01T09:00:00Z",
+        until_date="2024-01-31T10:00:00Z",
+    )
+    result = reader.read()
+    assert "record" in next(result)
+
+
+@pytest.fixture(scope="module")
+def oai_response_no_match():
+    response_data = """
+        <OAI-PMH xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd" xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+            <responseDate>2024-05-29T13:09:44Z</responseDate>
+            <request metadataPrefix="MARC21plus-1-xml" set="authorities:sachbegriff" verb="ListRecords" from="2024-01-01T09:00:00Z" until="2024-01-01T10:00:00Z">https://services.dnb.de/oai/repository</request>
+            <error code="noRecordsMatch"/>
+        </OAI-PMH>
+    """
+    return response_data
+
+
+def test_oaipmh_reader_no_records_match(httpserver, oai_response_no_match):
+    httpserver.expect_request("/oai/repository").respond_with_data(
+        response_data=oai_response_no_match, mimetype="application/xml"
+    )
+    reader = OAIPMHReader(
+        base_url=httpserver.url_for("/oai/repository"),
+        metadata_prefix="MARC21plus-1-xml",
+        set="authorities:sachbegriff",
+        from_date="2024-01-01T09:00:00Z",
+        until_date="2024-01-01T10:00:00Z",
+    )
+    result = reader.read()
+    with pytest.raises(ReaderError):
+        next(result)
+
+
 # FIXME: add test for csv reader