From 5f91984a0f570c20d3b172568190bb40d5f76e40 Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Thu, 13 Nov 2025 13:33:32 -0500
Subject: [PATCH 1/8] Added a json parser method to the Datalink mixins

---
 pyvo/dal/adhoc.py | 168 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 168 insertions(+)

diff --git a/pyvo/dal/adhoc.py b/pyvo/dal/adhoc.py
index 42d7d515..b377f71c 100644
--- a/pyvo/dal/adhoc.py
+++ b/pyvo/dal/adhoc.py
@@ -396,6 +396,48 @@ def iter_datalinks(self, preserve_order=False):
             yield from self._iter_datalinks_from_dlblock(
                 preserve_order=preserve_order)
 
+    def iter_parse_json_params(
+        self,
+        colname: str="cloud_access",
+        key: str="aws",
+        verbose: bool=False,
+        **match_params
+    ):
+
+        for irow, record in enumerate(self):
+            access_points = record.parse_json_params(
+                colname=colname,
+                key=key,
+                verbose=verbose,
+                **match_params
+                )
+            access_points.add_column([irow]*len(access_points), name="record_row", index=0)
+            if irow == 0:
+                new_table = access_points
+            else:
+                for row in access_points.iterrows():
+                    new_table.add_row(row)
+
+        return new_table
+
+    def iter_get_cloud_params(
+        self,
+        colname: str="cloud_access",
+        provider: str="aws",
+        verbose: bool=False,
+        **match_params
+    ):
+        for irow, record in enumerate(self):
+            # do the json parsing
+            cloud_params = record.get_cloud_params(colname, provider, verbose, **match_params)
+            cloud_params.add_column([irow]*len(cloud_params), name="record_row", index=0)
+            if irow == 0:
+                new_table = cloud_params
+            else:
+                for row in cloud_params.iterrows():
+                    new_table.add_row(row)
+
+        return new_table
 
 class DatalinkRecordMixin:
     """
@@ -445,6 +487,110 @@ def getdataset(self, timeout=None):
             # this should go to Record.getdataset()
             return super().getdataset(timeout=timeout)
 
+    def parse_json_params(
+        self,
+        colname: str="cloud_access",
+        key: str="aws",
+        verbose: bool=False,
+        **match_params
+        ):
+        """Parse information stored as JSON by key
+        
+        Parameters
+        ----------
+        colname: str
+            name of column to search in
+        provider: str, optional
+            name of data provider: only 'aws' is presently supported.
+        verbose: bool
+            If True, print progress and debug text.
+            
+        Return
+        ------
+        A dict or a list of dict of parameters for every row in products
+
+        """
+        import json
+
+        # init results table (avoiding adding import of astropy.table.Table)
+        new_table = TableElement(VOTableFile()).to_table()
+        
+        if verbose:
+            print(f'searching for and processing json column {colname}')
+
+        try:
+            jsontxt  = self[colname]
+            jsonDict = json.loads(jsontxt)
+            if key not in jsonDict and verbose:
+                print(f'No key "{key}" found for record'
+                        'in column "{colname}"')
+            else:
+                p_params = jsonDict[key]
+                checks = []
+                for k, value in match_params.items():
+                    checks.append(p_params.getitem(k, value) == value)
+
+                if all(checks):
+                    if not isinstance(p_params, list):
+                        p_params = [p_params]
+                    colnames = list(p_params[0].keys())
+                    colvals = [[] for _ in colnames]
+                    for ppar in p_params:
+                        for idx, val in enumerate(ppar.values()):
+                            colvals[idx].append(val)
+                    new_table.add_columns(cols=colvals, names=colnames)
+
+        except KeyError:
+            # no json column, return empty list
+            if verbose:
+                print(f'No column {colname} found for record.')
+
+        return new_table
+
+    def get_cloud_params(self, colname="cloud_access", provider="aws", verbose=False, **match_params):
+        """Parse information stored as JSON by key
+        
+        Parameters
+        ----------
+        colname: str
+            name of column to search in
+        provider: str, optional
+            name of data provider: only 'aws' is presently supported.
+        verbose: bool
+            If True, print progress and debug text.
+            
+        Return
+        ------
+        An astropy Table with parameters for every row in the datalinks
+
+        """
+        dl_results = self.getdatalink()
+        products = dl_results.bysemantics("#this")
+
+
+        for irow, row in enumerate(products):
+            # if no colname column, there is nothing to do    
+            try:
+                access_points = row.parse_json_params(
+                    colname=colname,
+                    key=provider,
+                    verbose=verbose,
+                    **match_params
+                    )
+                access_points.add_column([irow]*len(access_points), name="datalink_row", index=0)
+                if irow == 0:
+                    new_table = access_points
+                else:
+                    for row in access_points.iterrows():
+                        new_table.add_row(row)
+            except KeyError:
+                # no json column, continue
+                if verbose:
+                    print(f'No column {colname} found for row {irow}')
+                new_table = TableElement(VOTableFile()).to_table()
+                continue
+
+        return new_table
 
 class DatalinkService(DALService, AvailabilityMixin, CapabilityMixin):
     """
@@ -839,6 +985,28 @@ def from_result_url(cls, result_url, *, session=None, original_row=None):
         res.original_row = original_row
         return res
 
+    def get_cloud_params(self, colname="cloud_access", provider="aws", verbose=False, **match_params):
+        products = list(self.bysemantics("#this"))
+        rows_access_points = [[] for i in range(len(products))]
+        
+        for irow, row in enumerate(products):
+                    # if no colname column, there is nothing to do    
+            try:
+                access_points  = row.parse_json_params(
+                    colname=colname,
+                    key=provider,
+                    verbose=verbose,
+                    **match_params
+                    )
+                rows_access_points[irow].append(access_points)
+            except KeyError:
+                # no json column, continue
+                if verbose:
+                    print(f'No column {colname} found for row {irow}')
+                continue
+
+        return rows_access_points
+
 
 class SodaRecordMixin:
     """

From 36370b3c7876f2d643305c91a97a21b9b5202246 Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Fri, 21 Nov 2025 16:43:09 -0500
Subject: [PATCH 2/8] Upated iter method to use iter_datalinks, added
 documentation and tests

---
 docs/dal/index.rst              |   9 +++
 pyvo/dal/adhoc.py               | 102 +++++++++++++++++++++++++++-----
 pyvo/dal/tests/test_datalink.py |  73 +++++++++++++++++++++++
 3 files changed, 170 insertions(+), 14 deletions(-)

diff --git a/docs/dal/index.rst b/docs/dal/index.rst
index 3d2b566b..7f05dd77 100644
--- a/docs/dal/index.rst
+++ b/docs/dal/index.rst
@@ -869,6 +869,15 @@ DatalinkResults using
     >>> next(datalink.bysemantics("#this")).content_type
     'application/fits'
 
+As data becomes available from different cloud providers, some services are
+including cloud access information in the associated Datalink in JSON format.
+The ``get_cloud_params`` and ``iter_get_cloud_params`` fucntions for
+Records and Results respectively return an ``astropy.Table`` with the
+parameters specified to access data via the cloud service provider specified.
+
+More generic functions, ``parse_json_params`` and ``iter_parse_json_params``,
+act directly on the Record or Results object and can parse JSON columns with
+a given column name, key, and optionally parameters to match.
 
 Server-side processing
 ----------------------
diff --git a/pyvo/dal/adhoc.py b/pyvo/dal/adhoc.py
index b377f71c..6dff390d 100644
--- a/pyvo/dal/adhoc.py
+++ b/pyvo/dal/adhoc.py
@@ -403,7 +403,28 @@ def iter_parse_json_params(
         verbose: bool=False,
         **match_params
     ):
+        """
+        Iterate over all Records in a DalResult and return parsed json parameters.
+
+        Parameters
+        ----------
+        colname : str, optional
+            The column containing JSON to be parsed, by default "cloud_access"
+        key : str, optional
+            The key to filter JSON results by, by default "aws"
+        verbose : bool, optional
+            Whether to print progress and errors, by default False
+        **match_params : str, optional
+            Any further parameters to match on.
 
+        Returns
+        -------
+        astropy.Table
+            A table containing the JSON parameters separated into columns, each
+            row corresponding to a matching JSON entry for each DataLinkRecord
+            for each row of the original DalResult.
+
+        """
         for irow, record in enumerate(self):
             access_points = record.parse_json_params(
                 colname=colname,
@@ -427,9 +448,55 @@ def iter_get_cloud_params(
         verbose: bool=False,
         **match_params
     ):
-        for irow, record in enumerate(self):
+        """
+        Iterate over all Records in a DalResult and return parsed cloud parameters.
+
+        Parameters
+        ----------
+        colname : str, optional
+            The column containing JSON to be parsed, by default "cloud_access"
+        provider : str, optional
+            The key to filter JSON results by, by default "aws"
+        verbose : bool, optional
+            Whether to print progress and errors, by default False
+        **match_params : str, optional
+            Any further parameters to match on.
+
+        Returns
+        -------
+        astropy.Table
+            A table containing the JSON parameters separated into columns, each
+            row corresponding to matching JSON entries from each Record.
+
+        """
+        for irow, dl_results in enumerate(self.iter_datalinks()):
+
+            products = dl_results.bysemantics("#this")
+
+            for jrow, row in enumerate(products):
+                # if no colname column, there is nothing to do    
+                try:
+                    access_points = row.parse_json_params(
+                        colname=colname,
+                        key=provider,
+                        verbose=verbose,
+                        **match_params
+                        )
+                    access_points.add_column([jrow]*len(access_points), name="datalink_row", index=0)
+                    if jrow == 0:
+                        new_dl_table = access_points
+                    else:
+                        for row in access_points.iterrows():
+                            new_dl_table.add_row(row)
+                except KeyError:
+                    # no json column, continue
+                    if verbose:
+                        print(f'No column {colname} found for row {irow}, datalink {jrow}')
+                    new_dl_table = TableElement(VOTableFile()).to_table()
+                    continue
+
             # do the json parsing
-            cloud_params = record.get_cloud_params(colname, provider, verbose, **match_params)
+            cloud_params = access_points
             cloud_params.add_column([irow]*len(cloud_params), name="record_row", index=0)
             if irow == 0:
                 new_table = cloud_params
@@ -498,16 +565,20 @@ def parse_json_params(
         
         Parameters
         ----------
-        colname: str
-            name of column to search in
-        provider: str, optional
-            name of data provider: only 'aws' is presently supported.
-        verbose: bool
-            If True, print progress and debug text.
-            
-        Return
-        ------
-        A dict or a list of dict of parameters for every row in products
+        colname : str, optional
+            The column containing JSON to be parsed, by default "cloud_access"
+        key : str, optional
+            The key to filter JSON results by, by default "aws"
+        verbose : bool, optional
+            Whether to print progress and errors, by default False
+        **match_params : str, optional
+            Any further parameters to match on.
+
+        Returns
+        -------
+        astropy.Table
+            A table containing the JSON parameters separated into columns, each
+            row representing a matching JSON entry.
 
         """
         import json
@@ -548,7 +619,7 @@ def parse_json_params(
         return new_table
 
     def get_cloud_params(self, colname="cloud_access", provider="aws", verbose=False, **match_params):
-        """Parse information stored as JSON by key
+        """Parse cloud information stored as JSON by provider
         
         Parameters
         ----------
@@ -558,10 +629,13 @@ def get_cloud_params(self, colname="cloud_access", provider="aws", verbose=False
             name of data provider: only 'aws' is presently supported.
         verbose: bool
             If True, print progress and debug text.
+        **match_params
             
         Return
         ------
-        An astropy Table with parameters for every row in the datalinks
+        astropy.Table
+            A table containing the JSON parameters separated into columns,
+            each row being a unique JSON entry and/or from a different DatalinkRecord.
 
         """
         dl_results = self.getdatalink()
diff --git a/pyvo/dal/tests/test_datalink.py b/pyvo/dal/tests/test_datalink.py
index 559d2c92..14a40b9c 100644
--- a/pyvo/dal/tests/test_datalink.py
+++ b/pyvo/dal/tests/test_datalink.py
@@ -4,10 +4,12 @@
 Tests for pyvo.dal.datalink
 """
 from functools import partial
+from io import BytesIO
 import re
 
 import pytest
 
+from astropy.io.votable import parse, writeto, from_table
 import pyvo as vo
 from pyvo.dal.adhoc import DatalinkResults, DALServiceError
 from pyvo.dal.sia2 import SIA2Results
@@ -74,6 +76,21 @@ def callback(request, context):
     ) as matcher:
         yield matcher
 
+@pytest.fixture()
+def datalink_cloud(mocker):
+    def callback(request, context): 
+        dl_base = parse('pyvo/dal/tests/data/datalink/datalink.xml')
+        dl_base_table = dl_base.get_first_table().to_table()
+        cloud_access_str = '{"aws": {"bucket_name": "test", "key":"path/to/cloudfile.fits", "region": "us-west-2"}}'
+        dl_base_table.add_column([cloud_access_str]*4, name='cloud_access')
+        out = BytesIO()
+        writeto(from_table(dl_base_table), out)
+        return out.getvalue()
+
+    with mocker.register_uri(
+        'GET', 'http://example.com/datalink-cloud.xml', content=callback
+    ) as matcher:
+        yield matcher
 
 @pytest.fixture()
 def obscore_datalink(mocker):
@@ -336,3 +353,59 @@ def test_no_datalink():
     result = results[0]
     with pytest.raises(DALServiceError, match="No datalink found for record."):
         result.getdatalink()
+
+@pytest.mark.filterwarnings("ignore::astropy.io.votable.exceptions.E02")
+@pytest.mark.usefixtures('datalink_cloud')
+class TestJsonColumns:
+    """Tests for producing datalinks from tables containing links to
+    datalink documents.
+    """
+
+    res = testing.create_dalresults([
+            {"name": "access_url", "datatype": "char", "arraysize": "*",
+                "ucd": "meta.ref.url"},
+            {"name": "access_format", "datatype": "char", "arraysize": "*",
+                "utype": "meta.code.mime"},
+            {"name": "cloud_access", "datatype": "char", "arraysize": "*"},],
+            [("http://example.com/datalink-cloud.xml",
+                "application/x-votable+xml;content=datalink",
+                '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}',),
+                ("http://example.com/datalink-cloud.xml",
+                "application/x-votable+xml;content=datalink",
+                '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',)],
+            resultsClass=SIA2Results
+        )
+    def test_record_w_json(self):
+
+
+        parsed_json_matches = self.res[0].parse_json_params("cloud_access", "aws")
+        assert parsed_json_matches[0]["bucket_name"] == "test"
+        assert parsed_json_matches[0]["key"] == "path/to/file1.fits"
+        assert parsed_json_matches[0]["region"] == "us-west-2"
+
+    def test_iter_json(self):
+
+        parsed_json_matches = self.res.iter_parse_json_params("cloud_access", "aws")
+        assert parsed_json_matches[0]["record_row"] == 0
+        assert parsed_json_matches[0]["bucket_name"] == "test"
+        assert parsed_json_matches[0]["key"] == "path/to/file1.fits"
+        assert parsed_json_matches[0]["region"] == "us-west-2"
+        assert parsed_json_matches[1]["record_row"] == 1
+        assert parsed_json_matches[1]["key"] == "path/to/file2.fits"
+
+    def test_datalink_json(self):
+        parsed_cloud_params = self.res[0].get_cloud_params("cloud_access", "aws")
+        assert parsed_cloud_params[0]["bucket_name"] == "test"
+        assert parsed_cloud_params[0]["key"] == "path/to/cloudfile.fits"
+        assert parsed_cloud_params[0]["region"] == "us-west-2"
+
+    def test_iter_datalink_json(self):
+        parsed_json_matches = self.res.iter_get_cloud_params("cloud_access", "aws")
+        assert parsed_json_matches[0]["record_row"] == 0
+        assert parsed_json_matches[0]["datalink_row"] == 0
+        assert parsed_json_matches[0]["bucket_name"] == "test"
+        assert parsed_json_matches[0]["key"] == "path/to/cloudfile.fits"
+        assert parsed_json_matches[0]["region"] == "us-west-2"
+        assert parsed_json_matches[1]["record_row"] == 1
+        assert parsed_json_matches[1]["datalink_row"] == 0
+        assert parsed_json_matches[1]["key"] == "path/to/cloudfile.fits"
\ No newline at end of file

From b8a6b583eb4e32f9128fb327440e4d7ae466ad90 Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Mon, 24 Nov 2025 15:28:49 -0500
Subject: [PATCH 3/8] Upated documentation, removed duplicate code, fixed
 formatting

---
 docs/dal/index.rst              |  4 +++-
 pyvo/dal/adhoc.py               | 22 ----------------------
 pyvo/dal/tests/test_datalink.py |  2 +-
 3 files changed, 4 insertions(+), 24 deletions(-)

diff --git a/docs/dal/index.rst b/docs/dal/index.rst
index 7f05dd77..858c99e3 100644
--- a/docs/dal/index.rst
+++ b/docs/dal/index.rst
@@ -869,9 +869,11 @@ DatalinkResults using
     >>> next(datalink.bysemantics("#this")).content_type
     'application/fits'
 
+Cloud Access Information [subject to change]
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 As data becomes available from different cloud providers, some services are
 including cloud access information in the associated Datalink in JSON format.
-The ``get_cloud_params`` and ``iter_get_cloud_params`` fucntions for
+The ``get_cloud_params`` and ``iter_get_cloud_params`` functions for
 Records and Results respectively return an ``astropy.Table`` with the
 parameters specified to access data via the cloud service provider specified.
 
diff --git a/pyvo/dal/adhoc.py b/pyvo/dal/adhoc.py
index 6dff390d..779dc1d8 100644
--- a/pyvo/dal/adhoc.py
+++ b/pyvo/dal/adhoc.py
@@ -1059,28 +1059,6 @@ def from_result_url(cls, result_url, *, session=None, original_row=None):
         res.original_row = original_row
         return res
 
-    def get_cloud_params(self, colname="cloud_access", provider="aws", verbose=False, **match_params):
-        products = list(self.bysemantics("#this"))
-        rows_access_points = [[] for i in range(len(products))]
-        
-        for irow, row in enumerate(products):
-                    # if no colname column, there is nothing to do    
-            try:
-                access_points  = row.parse_json_params(
-                    colname=colname,
-                    key=provider,
-                    verbose=verbose,
-                    **match_params
-                    )
-                rows_access_points[irow].append(access_points)
-            except KeyError:
-                # no json column, continue
-                if verbose:
-                    print(f'No column {colname} found for row {irow}')
-                continue
-
-        return rows_access_points
-
 
 class SodaRecordMixin:
     """
diff --git a/pyvo/dal/tests/test_datalink.py b/pyvo/dal/tests/test_datalink.py
index 14a40b9c..695efdaf 100644
--- a/pyvo/dal/tests/test_datalink.py
+++ b/pyvo/dal/tests/test_datalink.py
@@ -408,4 +408,4 @@ def test_iter_datalink_json(self):
         assert parsed_json_matches[0]["region"] == "us-west-2"
         assert parsed_json_matches[1]["record_row"] == 1
         assert parsed_json_matches[1]["datalink_row"] == 0
-        assert parsed_json_matches[1]["key"] == "path/to/cloudfile.fits"
\ No newline at end of file
+        assert parsed_json_matches[1]["key"] == "path/to/cloudfile.fits"

From e0dcec8117c3a120da921e21db3eaf2b7d5dc90d Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Wed, 3 Dec 2025 14:01:15 -0500
Subject: [PATCH 4/8] docstring updates

---
 pyvo/dal/adhoc.py | 63 ++++++++++++++++++++++++++---------------------
 1 file changed, 35 insertions(+), 28 deletions(-)

diff --git a/pyvo/dal/adhoc.py b/pyvo/dal/adhoc.py
index 779dc1d8..350a780d 100644
--- a/pyvo/dal/adhoc.py
+++ b/pyvo/dal/adhoc.py
@@ -398,8 +398,8 @@ def iter_datalinks(self, preserve_order=False):
 
     def iter_parse_json_params(
         self,
+        json_key: str,
         colname: str="cloud_access",
-        key: str="aws",
         verbose: bool=False,
         **match_params
     ):
@@ -408,14 +408,14 @@ def iter_parse_json_params(
 
         Parameters
         ----------
+        json_key : str
+            The primary key by which to filter JSON results.
         colname : str, optional
-            The column containing JSON to be parsed, by default "cloud_access"
-        key : str, optional
-            The key to filter JSON results by, by default "aws"
+            The column containing JSON to be parsed, by default "cloud_access".
         verbose : bool, optional
-            Whether to print progress and errors, by default False
+            Whether to print progress and errors, by default False.
         **match_params : str, optional
-            Any further parameters to match on.
+            Further parameters on which to match beyond `json_key`.
 
         Returns
         -------
@@ -428,7 +428,7 @@ def iter_parse_json_params(
         for irow, record in enumerate(self):
             access_points = record.parse_json_params(
                 colname=colname,
-                key=key,
+                json_key=json_key,
                 verbose=verbose,
                 **match_params
                 )
@@ -443,8 +443,8 @@ def iter_parse_json_params(
 
     def iter_get_cloud_params(
         self,
+        provider: str,
         colname: str="cloud_access",
-        provider: str="aws",
         verbose: bool=False,
         **match_params
     ):
@@ -453,14 +453,14 @@ def iter_get_cloud_params(
 
         Parameters
         ----------
+        provider : str
+            Name of the data provider.
         colname : str, optional
-            The column containing JSON to be parsed, by default "cloud_access"
-        provider : str, optional
-            The key to filter JSON results by, by default "aws"
+            The column containing cloud access JSON, by default "cloud_access".
         verbose : bool, optional
-            Whether to print progress and errors, by default False
+            Whether to print debug text, by default False.
         **match_params : str, optional
-            Any further parameters to match on.
+            Further parameters on which to match beyond `provider`.
 
         Returns
         -------
@@ -478,7 +478,7 @@ def iter_get_cloud_params(
                 try:
                     access_points = row.parse_json_params(
                         colname=colname,
-                        key=provider,
+                        json_key=provider,
                         verbose=verbose,
                         **match_params
                         )
@@ -556,8 +556,8 @@ def getdataset(self, timeout=None):
 
     def parse_json_params(
         self,
+        json_key: str,
         colname: str="cloud_access",
-        key: str="aws",
         verbose: bool=False,
         **match_params
         ):
@@ -565,14 +565,14 @@ def parse_json_params(
         
         Parameters
         ----------
+        json_key : str
+            The primary key by which to filter JSON results
         colname : str, optional
             The column containing JSON to be parsed, by default "cloud_access"
-        key : str, optional
-            The key to filter JSON results by, by default "aws"
         verbose : bool, optional
             Whether to print progress and errors, by default False
         **match_params : str, optional
-            Any further parameters to match on.
+            Further parameters on which to match beyond `json_key`.
 
         Returns
         -------
@@ -592,11 +592,11 @@ def parse_json_params(
         try:
             jsontxt  = self[colname]
             jsonDict = json.loads(jsontxt)
-            if key not in jsonDict and verbose:
-                print(f'No key "{key}" found for record'
+            if json_key not in jsonDict and verbose:
+                print(f'No key "{json_key}" found for record'
                         'in column "{colname}"')
             else:
-                p_params = jsonDict[key]
+                p_params = jsonDict[json_key]
                 checks = []
                 for k, value in match_params.items():
                     checks.append(p_params.getitem(k, value) == value)
@@ -618,18 +618,25 @@ def parse_json_params(
 
         return new_table
 
-    def get_cloud_params(self, colname="cloud_access", provider="aws", verbose=False, **match_params):
+    def get_cloud_params(
+        self,
+        provider: str,
+        colname: str = "cloud_access",
+        verbose: bool = False,
+        **match_params
+        ):
         """Parse cloud information stored as JSON by provider
         
         Parameters
         ----------
-        colname: str
-            name of column to search in
-        provider: str, optional
-            name of data provider: only 'aws' is presently supported.
-        verbose: bool
-            If True, print progress and debug text.
+        provider: str
+            Name of the data provider
+        colname: str, optional
+            The column name containing the cloud access JSON, by default "cloud_access"
+        verbose: bool, optional
+            If True, print progress and debug text, by default False
         **match_params
+            Further parameters on which to match beyond `provider`.
             
         Return
         ------

From f69127ca75105e6e2d13d99d46798ce346b92292 Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Wed, 3 Dec 2025 15:15:21 -0500
Subject: [PATCH 5/8] added changelog entry

---
 CHANGES.rst | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index 06e81a8d..5d232a77 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -3,7 +3,8 @@
 
 Enhancements and Fixes
 ----------------------
-
+- Added functionality to the DatalinkRecordMixin and the DatalinkResultsMixin
+  to handle basic parsing of JSON entries
 
 
 Deprecations and Removals

From 2eb66b4df336475af56f339ceea4b57194247179 Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Fri, 5 Dec 2025 16:39:42 -0500
Subject: [PATCH 6/8] added column guesser based on utype and ucd, changed
 parse_json to static function

---
 pyvo/dal/adhoc.py               | 150 ++++++++++++--------------------
 pyvo/dal/tests/test_datalink.py |  60 ++++++++-----
 2 files changed, 97 insertions(+), 113 deletions(-)

diff --git a/pyvo/dal/adhoc.py b/pyvo/dal/adhoc.py
index 350a780d..1c983596 100644
--- a/pyvo/dal/adhoc.py
+++ b/pyvo/dal/adhoc.py
@@ -6,6 +6,7 @@
 import warnings
 import copy
 import requests
+import json
 
 from .query import DALResults, DALQuery, DALService, Record
 from .exceptions import DALServiceError
@@ -396,51 +397,6 @@ def iter_datalinks(self, preserve_order=False):
             yield from self._iter_datalinks_from_dlblock(
                 preserve_order=preserve_order)
 
-    def iter_parse_json_params(
-        self,
-        json_key: str,
-        colname: str="cloud_access",
-        verbose: bool=False,
-        **match_params
-    ):
-        """
-        Iterate over all Records in a DalResult and return parsed json parameters.
-
-        Parameters
-        ----------
-        json_key : str
-            The primary key by which to filter JSON results.
-        colname : str, optional
-            The column containing JSON to be parsed, by default "cloud_access".
-        verbose : bool, optional
-            Whether to print progress and errors, by default False.
-        **match_params : str, optional
-            Further parameters on which to match beyond `json_key`.
-
-        Returns
-        -------
-        astropy.Table
-            A table containing the JSON parameters separated into columns, each
-            row corresponding to a matching JSON entry for each DataLinkRecord
-            for each row of the original DalResult.
-
-        """
-        for irow, record in enumerate(self):
-            access_points = record.parse_json_params(
-                colname=colname,
-                json_key=json_key,
-                verbose=verbose,
-                **match_params
-                )
-            access_points.add_column([irow]*len(access_points), name="record_row", index=0)
-            if irow == 0:
-                new_table = access_points
-            else:
-                for row in access_points.iterrows():
-                    new_table.add_row(row)
-
-        return new_table
-
     def iter_get_cloud_params(
         self,
         provider: str,
@@ -475,9 +431,10 @@ def iter_get_cloud_params(
 
             for jrow, row in enumerate(products):
                 # if no colname column, there is nothing to do    
-                try:
+                jsontxt = row._guess_cloud_column(colname=colname)
+                if jsontxt:
                     access_points = row.parse_json_params(
-                        colname=colname,
+                        json_txt=jsontxt,
                         json_key=provider,
                         verbose=verbose,
                         **match_params
@@ -488,15 +445,14 @@ def iter_get_cloud_params(
                     else:
                         for row in access_points.iterrows():
                             new_dl_table.add_row(row)
-                except KeyError:
+                else:
                     # no json column, continue
                     if verbose:
-                        print(f'No column {colname} found for row {irow}, datalink {jrow}')
+                        print(f'No column {colname} found for Results row {irow}, datalink row {jrow}')
                     new_dl_table = TableElement(VOTableFile()).to_table()
-                    continue
 
             # do the json parsing
-            cloud_params = access_points
+            cloud_params = new_dl_table
             cloud_params.add_column([irow]*len(cloud_params), name="record_row", index=0)
             if irow == 0:
                 new_table = cloud_params
@@ -554,10 +510,10 @@ def getdataset(self, timeout=None):
             # this should go to Record.getdataset()
             return super().getdataset(timeout=timeout)
 
+    @staticmethod
     def parse_json_params(
-        self,
+        json_txt: str,
         json_key: str,
-        colname: str="cloud_access",
         verbose: bool=False,
         **match_params
         ):
@@ -565,10 +521,10 @@ def parse_json_params(
         
         Parameters
         ----------
+        json_txt : str
+            Text interpreted as JSON
         json_key : str
             The primary key by which to filter JSON results
-        colname : str, optional
-            The column containing JSON to be parsed, by default "cloud_access"
         verbose : bool, optional
             Whether to print progress and errors, by default False
         **match_params : str, optional
@@ -581,43 +537,52 @@ def parse_json_params(
             row representing a matching JSON entry.
 
         """
-        import json
 
         # init results table (avoiding adding import of astropy.table.Table)
         new_table = TableElement(VOTableFile()).to_table()
-        
-        if verbose:
-            print(f'searching for and processing json column {colname}')
 
-        try:
-            jsontxt  = self[colname]
-            jsonDict = json.loads(jsontxt)
-            if json_key not in jsonDict and verbose:
-                print(f'No key "{json_key}" found for record'
-                        'in column "{colname}"')
-            else:
-                p_params = jsonDict[json_key]
-                checks = []
-                for k, value in match_params.items():
-                    checks.append(p_params.getitem(k, value) == value)
-
-                if all(checks):
-                    if not isinstance(p_params, list):
-                        p_params = [p_params]
-                    colnames = list(p_params[0].keys())
-                    colvals = [[] for _ in colnames]
-                    for ppar in p_params:
-                        for idx, val in enumerate(ppar.values()):
-                            colvals[idx].append(val)
-                    new_table.add_columns(cols=colvals, names=colnames)
-
-        except KeyError:
-            # no json column, return empty list
-            if verbose:
-                print(f'No column {colname} found for record.')
+        jsonDict = json.loads(json_txt)
+        if json_key not in jsonDict and verbose:
+            print(f'No key "{json_key}" found in json_txt given.')
+        else:
+            p_params = jsonDict[json_key]
+            checks = []
+            for k, value in match_params.items():
+                checks.append(p_params.getitem(k, value) == value)
+
+            if all(checks):
+                if not isinstance(p_params, list):
+                    p_params = [p_params]
+                colnames = list(p_params[0].keys())
+                colvals = [[] for _ in colnames]
+                for ppar in p_params:
+                    for idx, val in enumerate(ppar.values()):
+                        colvals[idx].append(val)
+                new_table.add_columns(cols=colvals, names=colnames)
 
         return new_table
 
+    def _guess_cloud_column(self, colname="cloud_access"):
+        """returns a guess for a URI to a data product in row.
+
+        This tries a few heuristics based on how cloud access or records might
+        be marked up.  This will return None if row does not look as if
+        it contained a cloud access column.
+        """
+        if hasattr(self, colname):
+            return getattr(self, colname)
+
+        if colname in self:
+            return self[colname]
+
+        cloud_access = self.getbyutype("adhoc:cloudstorage")
+        if cloud_access:
+            return cloud_access
+
+        cloud_access = self.getbyucd("meta.ref.cloudstorage") 
+        if cloud_access:
+            return cloud_access
+
     def get_cloud_params(
         self,
         provider: str,
@@ -651,10 +616,11 @@ def get_cloud_params(
 
         for irow, row in enumerate(products):
             # if no colname column, there is nothing to do    
-            try:
+            cloud_json = row._guess_cloud_column(colname=colname)
+            if cloud_json:
                 access_points = row.parse_json_params(
-                    colname=colname,
-                    key=provider,
+                    json_txt=cloud_json,
+                    json_key=provider,
                     verbose=verbose,
                     **match_params
                     )
@@ -664,12 +630,12 @@ def get_cloud_params(
                 else:
                     for row in access_points.iterrows():
                         new_table.add_row(row)
-            except KeyError:
-                # no json column, continue
+            else:
+                # no json column, return None
                 if verbose:
                     print(f'No column {colname} found for row {irow}')
-                new_table = TableElement(VOTableFile()).to_table()
-                continue
+                new_table = None
+                break
 
         return new_table
 
diff --git a/pyvo/dal/tests/test_datalink.py b/pyvo/dal/tests/test_datalink.py
index 695efdaf..e865f5a5 100644
--- a/pyvo/dal/tests/test_datalink.py
+++ b/pyvo/dal/tests/test_datalink.py
@@ -77,18 +77,38 @@ def callback(request, context):
         yield matcher
 
 @pytest.fixture()
-def datalink_cloud(mocker):
+def datalink_cloud1(mocker):
     def callback(request, context): 
         dl_base = parse('pyvo/dal/tests/data/datalink/datalink.xml')
         dl_base_table = dl_base.get_first_table().to_table()
         cloud_access_str = '{"aws": {"bucket_name": "test", "key":"path/to/cloudfile.fits", "region": "us-west-2"}}'
         dl_base_table.add_column([cloud_access_str]*4, name='cloud_access')
         out = BytesIO()
-        writeto(from_table(dl_base_table), out)
+        votable = from_table(dl_base_table)
+        votable.get_first_table().get_field_by_id("cloud_access").utype = "adhoc:cloudstorage"
+        writeto(votable, out)
         return out.getvalue()
 
     with mocker.register_uri(
-        'GET', 'http://example.com/datalink-cloud.xml', content=callback
+        'GET', 'http://example.com/datalink-cloud1.xml', content=callback
+    ) as matcher:
+        yield matcher
+
+@pytest.fixture()
+def datalink_cloud2(mocker):
+    def callback(request, context): 
+        dl_base = parse('pyvo/dal/tests/data/datalink/datalink.xml')
+        dl_base_table = dl_base.get_first_table().to_table()
+        cloud_access_str = '{"aws": {"bucket_name": "test", "key":"path/to/cloudfile.fits", "region": "us-west-2"}}'
+        dl_base_table.add_column([cloud_access_str]*4, name='cloud_access')
+        out = BytesIO()
+        votable = from_table(dl_base_table)
+        votable.get_first_table().get_field_by_id("cloud_access").ucd = "meta.ref.cloudstorage"
+        writeto(votable, out)
+        return out.getvalue()
+
+    with mocker.register_uri(
+        'GET', 'http://example.com/datalink-cloud2.xml', content=callback
     ) as matcher:
         yield matcher
 
@@ -355,7 +375,7 @@ def test_no_datalink():
         result.getdatalink()
 
 @pytest.mark.filterwarnings("ignore::astropy.io.votable.exceptions.E02")
-@pytest.mark.usefixtures('datalink_cloud')
+@pytest.mark.usefixtures('datalink_cloud1', 'datalink_cloud2')
 class TestJsonColumns:
     """Tests for producing datalinks from tables containing links to
     datalink documents.
@@ -366,41 +386,39 @@ class TestJsonColumns:
                 "ucd": "meta.ref.url"},
             {"name": "access_format", "datatype": "char", "arraysize": "*",
                 "utype": "meta.code.mime"},
-            {"name": "cloud_access", "datatype": "char", "arraysize": "*"},],
-            [("http://example.com/datalink-cloud.xml",
+            {"name": "cloud_access", "datatype": "char", "arraysize": "*",
+                "utype": "adhoc:cloudstorage", "ucd": "meta.ref.cloudstorage"},],
+            [("http://example.com/datalink-cloud1.xml",
                 "application/x-votable+xml;content=datalink",
                 '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}',),
-                ("http://example.com/datalink-cloud.xml",
+                ("http://example.com/datalink-cloud2.xml",
                 "application/x-votable+xml;content=datalink",
                 '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',)],
             resultsClass=SIA2Results
         )
     def test_record_w_json(self):
 
-
-        parsed_json_matches = self.res[0].parse_json_params("cloud_access", "aws")
+        jsontxt = '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}'
+        parsed_json_matches = self.res[0].parse_json_params(json_txt=jsontxt, json_key="aws")
         assert parsed_json_matches[0]["bucket_name"] == "test"
         assert parsed_json_matches[0]["key"] == "path/to/file1.fits"
         assert parsed_json_matches[0]["region"] == "us-west-2"
 
-    def test_iter_json(self):
-
-        parsed_json_matches = self.res.iter_parse_json_params("cloud_access", "aws")
-        assert parsed_json_matches[0]["record_row"] == 0
-        assert parsed_json_matches[0]["bucket_name"] == "test"
-        assert parsed_json_matches[0]["key"] == "path/to/file1.fits"
-        assert parsed_json_matches[0]["region"] == "us-west-2"
-        assert parsed_json_matches[1]["record_row"] == 1
-        assert parsed_json_matches[1]["key"] == "path/to/file2.fits"
-
     def test_datalink_json(self):
-        parsed_cloud_params = self.res[0].get_cloud_params("cloud_access", "aws")
+        parsed_cloud_params = self.res[0].get_cloud_params(provider="aws", colname="cloud_access")
         assert parsed_cloud_params[0]["bucket_name"] == "test"
         assert parsed_cloud_params[0]["key"] == "path/to/cloudfile.fits"
         assert parsed_cloud_params[0]["region"] == "us-west-2"
 
+        parsed2 = self.res[0].get_cloud_params(provider="aws", colname="bad_col_name")
+        assert parsed_cloud_params == parsed2
+
+        parsed3 = self.res[1].get_cloud_params(provider="aws", colname="bad_col_name")
+        parsed4 = self.res[1].get_cloud_params(provider="aws", colname="cloud_access")
+        assert parsed3 == parsed4
+
     def test_iter_datalink_json(self):
-        parsed_json_matches = self.res.iter_get_cloud_params("cloud_access", "aws")
+        parsed_json_matches = self.res.iter_get_cloud_params(provider="aws", colname="cloud_access")
         assert parsed_json_matches[0]["record_row"] == 0
         assert parsed_json_matches[0]["datalink_row"] == 0
         assert parsed_json_matches[0]["bucket_name"] == "test"

From 7989c73a05a0fe9db0a1faaeeb3cbb147006891a Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Thu, 18 Dec 2025 16:24:44 -0800
Subject: [PATCH 7/8] Fixed handling of multiple entries for a single provider,
 improved tests, fixed changelog entry

---
 CHANGES.rst                     |  2 +-
 pyvo/dal/adhoc.py               | 36 ++++++++++++++++--------
 pyvo/dal/tests/test_datalink.py | 49 +++++++++++++++++++++++++++++----
 3 files changed, 68 insertions(+), 19 deletions(-)

diff --git a/CHANGES.rst b/CHANGES.rst
index 5d232a77..2677454d 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,7 +4,7 @@
 Enhancements and Fixes
 ----------------------
 - Added functionality to the DatalinkRecordMixin and the DatalinkResultsMixin
-  to handle basic parsing of JSON entries
+  to handle basic parsing of JSON entries [#709]
 
 
 Deprecations and Removals
diff --git a/pyvo/dal/adhoc.py b/pyvo/dal/adhoc.py
index 1c983596..22546b6d 100644
--- a/pyvo/dal/adhoc.py
+++ b/pyvo/dal/adhoc.py
@@ -540,25 +540,37 @@ def parse_json_params(
 
         # init results table (avoiding adding import of astropy.table.Table)
         new_table = TableElement(VOTableFile()).to_table()
-
+    
         jsonDict = json.loads(json_txt)
         if json_key not in jsonDict and verbose:
             print(f'No key "{json_key}" found in json_txt given.')
         else:
-            p_params = jsonDict[json_key]
+            # Expected format is a dictionary of providers as keys, with lists
+            # of dictionaries, for example:
+            # {"json_key1": [{"param1": p1val1, "param2": p2val1},
+            #                {"param1": p1val2, "param2": p2val2}]
+            #  "json_key2": [{"param1": p1val3, "param2": p2val3}]
+            # }
+            jkey_params = jsonDict[json_key]
+            if isinstance(jkey_params, dict):
+                jkey_params = [jkey_params]
             checks = []
-            for k, value in match_params.items():
-                checks.append(p_params.getitem(k, value) == value)
-
-            if all(checks):
-                if not isinstance(p_params, list):
-                    p_params = [p_params]
-                colnames = list(p_params[0].keys())
-                colvals = [[] for _ in colnames]
-                for ppar in p_params:
-                    for idx, val in enumerate(ppar.values()):
+            col_init = False
+            for params in jkey_params:
+                for k, value in match_params.items():
+                    checks.append(params.get(k, value) == value)
+
+                if all(checks):
+                    if not col_init:
+                        colnames = list(params.keys())
+                        colvals = [[] for _ in colnames]
+                        col_init = True
+                    for idx, val in enumerate(params.values()):
                         colvals[idx].append(val)
+            try:
                 new_table.add_columns(cols=colvals, names=colnames)
+            except UnboundLocalError:
+                pass
 
         return new_table
 
diff --git a/pyvo/dal/tests/test_datalink.py b/pyvo/dal/tests/test_datalink.py
index e865f5a5..70807c01 100644
--- a/pyvo/dal/tests/test_datalink.py
+++ b/pyvo/dal/tests/test_datalink.py
@@ -99,7 +99,9 @@ def datalink_cloud2(mocker):
     def callback(request, context): 
         dl_base = parse('pyvo/dal/tests/data/datalink/datalink.xml')
         dl_base_table = dl_base.get_first_table().to_table()
-        cloud_access_str = '{"aws": {"bucket_name": "test", "key":"path/to/cloudfile.fits", "region": "us-west-2"}}'
+        cloud_access_str = ('{"aws": '
+                            '[{"bucket_name": "test", "key": "path/to/cloudfile.fits", "region": "us-west-2"}, '
+                             '{"bucket_name": "test", "key": "path/to/cloudfile2.fits", "region": "us-west-2"}]}')
         dl_base_table.add_column([cloud_access_str]*4, name='cloud_access')
         out = BytesIO()
         votable = from_table(dl_base_table)
@@ -375,7 +377,7 @@ def test_no_datalink():
         result.getdatalink()
 
 @pytest.mark.filterwarnings("ignore::astropy.io.votable.exceptions.E02")
-@pytest.mark.usefixtures('datalink_cloud1', 'datalink_cloud2')
+@pytest.mark.usefixtures('datalink_cloud1', 'datalink_cloud2', 'datalink_product')
 class TestJsonColumns:
     """Tests for producing datalinks from tables containing links to
     datalink documents.
@@ -393,7 +395,10 @@ class TestJsonColumns:
                 '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}',),
                 ("http://example.com/datalink-cloud2.xml",
                 "application/x-votable+xml;content=datalink",
-                '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',)],
+                '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',),
+                 ("http://example.com/datalink.xml",
+                "application/x-votable+xml;content=datalink",
+                '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',),],
             resultsClass=SIA2Results
         )
     def test_record_w_json(self):
@@ -404,6 +409,17 @@ def test_record_w_json(self):
         assert parsed_json_matches[0]["key"] == "path/to/file1.fits"
         assert parsed_json_matches[0]["region"] == "us-west-2"
 
+    def test_extra_key(self):
+        # Check that giving extra kwargs matches parameters
+        jsontxt = '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}'
+        parsed_json_matches0 = self.res[0].parse_json_params(json_txt=jsontxt, json_key="aws")
+        parsed_json_matches1 = self.res[0].parse_json_params(json_txt=jsontxt, json_key="aws", region="us-west-2")
+
+        assert parsed_json_matches0 == parsed_json_matches1
+
+        parsed_json_matches2 = self.res[0].parse_json_params(json_txt=jsontxt, json_key="aws", region="us-west-1")
+        assert len(parsed_json_matches2) == 0
+
     def test_datalink_json(self):
         parsed_cloud_params = self.res[0].get_cloud_params(provider="aws", colname="cloud_access")
         assert parsed_cloud_params[0]["bucket_name"] == "test"
@@ -413,12 +429,29 @@ def test_datalink_json(self):
         parsed2 = self.res[0].get_cloud_params(provider="aws", colname="bad_col_name")
         assert parsed_cloud_params == parsed2
 
-        parsed3 = self.res[1].get_cloud_params(provider="aws", colname="bad_col_name")
-        parsed4 = self.res[1].get_cloud_params(provider="aws", colname="cloud_access")
-        assert parsed3 == parsed4
+    def test_datalink_guess_colname(self):
+        # Check that guessing by ucd or utype works when given a non-existant column name
+        parsed1 = self.res[1].get_cloud_params(provider="aws", colname="bad_col_name")
+        # Only one row in datalink has semantics "#this", only returning results from that row
+        assert len(parsed1) == 2
+        parsed2 = self.res[1].get_cloud_params(provider="aws", colname="cloud_access")
+        assert all(parsed1 == parsed2)
+
+    def test_existing_colname(self):
+        # Existing colname given, so does not guess. Column isn't json, so results shouldn't exist.
+        parsed_cloud_params = self.res[0].get_cloud_params(provider="aws", colname="service_def")
+        assert parsed_cloud_params is None
+
+    def no_column_in_datalink(self, capsys):
+        # All column guesses come back empty
+        parsed_cloud_params = self.res[1].get_cloud_params(provider="aws", colname="cloud_access", verbose=True)
+        assert "No column cloud_access" in capsys
+        assert parsed_cloud_params is None
 
     def test_iter_datalink_json(self):
         parsed_json_matches = self.res.iter_get_cloud_params(provider="aws", colname="cloud_access")
+        # 1 result from 1st datalink, 2 from 2nd, 0 from 3rd
+        assert len(parsed_json_matches) == 3
         assert parsed_json_matches[0]["record_row"] == 0
         assert parsed_json_matches[0]["datalink_row"] == 0
         assert parsed_json_matches[0]["bucket_name"] == "test"
@@ -427,3 +460,7 @@ def test_iter_datalink_json(self):
         assert parsed_json_matches[1]["record_row"] == 1
         assert parsed_json_matches[1]["datalink_row"] == 0
         assert parsed_json_matches[1]["key"] == "path/to/cloudfile.fits"
+        assert parsed_json_matches[2]["record_row"] == 1
+        assert parsed_json_matches[2]["datalink_row"] == 0
+        assert parsed_json_matches[2]["key"] == "path/to/cloudfile2.fits"
+        

From 2afc2291c169cb7e971e67afae8b5e893c2ff3ab Mon Sep 17 00:00:00 2001
From: Daniel Giles <daniel.k.giles@gmail.com>
Date: Fri, 19 Dec 2025 11:42:01 -0800
Subject: [PATCH 8/8] Formatting

---
 pyvo/dal/adhoc.py               | 37 +++++++++---------
 pyvo/dal/tests/test_datalink.py | 67 +++++++++++++++++++--------------
 2 files changed, 58 insertions(+), 46 deletions(-)

diff --git a/pyvo/dal/adhoc.py b/pyvo/dal/adhoc.py
index 22546b6d..155d3afc 100644
--- a/pyvo/dal/adhoc.py
+++ b/pyvo/dal/adhoc.py
@@ -400,8 +400,8 @@ def iter_datalinks(self, preserve_order=False):
     def iter_get_cloud_params(
         self,
         provider: str,
-        colname: str="cloud_access",
-        verbose: bool=False,
+        colname: str = "cloud_access",
+        verbose: bool = False,
         **match_params
     ):
         """
@@ -416,7 +416,7 @@ def iter_get_cloud_params(
         verbose : bool, optional
             Whether to print debug text, by default False.
         **match_params : str, optional
-            Further parameters on which to match beyond `provider`.
+            Further parameters on which to match beyond provider.
 
         Returns
         -------
@@ -430,7 +430,7 @@ def iter_get_cloud_params(
             products = dl_results.bysemantics("#this")
 
             for jrow, row in enumerate(products):
-                # if no colname column, there is nothing to do    
+                # if no colname column, there is nothing to do
                 jsontxt = row._guess_cloud_column(colname=colname)
                 if jsontxt:
                     access_points = row.parse_json_params(
@@ -438,7 +438,7 @@ def iter_get_cloud_params(
                         json_key=provider,
                         verbose=verbose,
                         **match_params
-                        )
+                    )
                     access_points.add_column([jrow]*len(access_points), name="datalink_row", index=0)
                     if jrow == 0:
                         new_dl_table = access_points
@@ -462,6 +462,7 @@ def iter_get_cloud_params(
 
         return new_table
 
+
 class DatalinkRecordMixin:
     """
     Mixin for record classes, providing functionallity for datalink.
@@ -514,11 +515,11 @@ def getdataset(self, timeout=None):
     def parse_json_params(
         json_txt: str,
         json_key: str,
-        verbose: bool=False,
+        verbose: bool = False,
         **match_params
-        ):
+    ):
         """Parse information stored as JSON by key
-        
+
         Parameters
         ----------
         json_txt : str
@@ -528,7 +529,7 @@ def parse_json_params(
         verbose : bool, optional
             Whether to print progress and errors, by default False
         **match_params : str, optional
-            Further parameters on which to match beyond `json_key`.
+            Further parameters on which to match beyond json_key.
 
         Returns
         -------
@@ -540,7 +541,7 @@ def parse_json_params(
 
         # init results table (avoiding adding import of astropy.table.Table)
         new_table = TableElement(VOTableFile()).to_table()
-    
+
         jsonDict = json.loads(json_txt)
         if json_key not in jsonDict and verbose:
             print(f'No key "{json_key}" found in json_txt given.')
@@ -591,7 +592,7 @@ def _guess_cloud_column(self, colname="cloud_access"):
         if cloud_access:
             return cloud_access
 
-        cloud_access = self.getbyucd("meta.ref.cloudstorage") 
+        cloud_access = self.getbyucd("meta.ref.cloudstorage")
         if cloud_access:
             return cloud_access
 
@@ -601,9 +602,9 @@ def get_cloud_params(
         colname: str = "cloud_access",
         verbose: bool = False,
         **match_params
-        ):
+    ):
         """Parse cloud information stored as JSON by provider
-        
+
         Parameters
         ----------
         provider: str
@@ -613,8 +614,8 @@ def get_cloud_params(
         verbose: bool, optional
             If True, print progress and debug text, by default False
         **match_params
-            Further parameters on which to match beyond `provider`.
-            
+            Further parameters on which to match beyond provider.
+
         Return
         ------
         astropy.Table
@@ -625,9 +626,8 @@ def get_cloud_params(
         dl_results = self.getdatalink()
         products = dl_results.bysemantics("#this")
 
-
         for irow, row in enumerate(products):
-            # if no colname column, there is nothing to do    
+            # if no colname column, there is nothing to do
             cloud_json = row._guess_cloud_column(colname=colname)
             if cloud_json:
                 access_points = row.parse_json_params(
@@ -635,7 +635,7 @@ def get_cloud_params(
                     json_key=provider,
                     verbose=verbose,
                     **match_params
-                    )
+                )
                 access_points.add_column([irow]*len(access_points), name="datalink_row", index=0)
                 if irow == 0:
                     new_table = access_points
@@ -651,6 +651,7 @@ def get_cloud_params(
 
         return new_table
 
+
 class DatalinkService(DALService, AvailabilityMixin, CapabilityMixin):
     """
     a representation of a Datalink service
diff --git a/pyvo/dal/tests/test_datalink.py b/pyvo/dal/tests/test_datalink.py
index 70807c01..a921a4a6 100644
--- a/pyvo/dal/tests/test_datalink.py
+++ b/pyvo/dal/tests/test_datalink.py
@@ -76,12 +76,14 @@ def callback(request, context):
     ) as matcher:
         yield matcher
 
+
 @pytest.fixture()
 def datalink_cloud1(mocker):
-    def callback(request, context): 
+    def callback(request, context):
         dl_base = parse('pyvo/dal/tests/data/datalink/datalink.xml')
         dl_base_table = dl_base.get_first_table().to_table()
-        cloud_access_str = '{"aws": {"bucket_name": "test", "key":"path/to/cloudfile.fits", "region": "us-west-2"}}'
+        cloud_access_str = ('{"aws": {"bucket_name": "test", '
+        '"key":"path/to/cloudfile.fits", "region": "us-west-2"}}')
         dl_base_table.add_column([cloud_access_str]*4, name='cloud_access')
         out = BytesIO()
         votable = from_table(dl_base_table)
@@ -94,14 +96,17 @@ def callback(request, context):
     ) as matcher:
         yield matcher
 
+
 @pytest.fixture()
 def datalink_cloud2(mocker):
-    def callback(request, context): 
+    def callback(request, context):
         dl_base = parse('pyvo/dal/tests/data/datalink/datalink.xml')
         dl_base_table = dl_base.get_first_table().to_table()
         cloud_access_str = ('{"aws": '
-                            '[{"bucket_name": "test", "key": "path/to/cloudfile.fits", "region": "us-west-2"}, '
-                             '{"bucket_name": "test", "key": "path/to/cloudfile2.fits", "region": "us-west-2"}]}')
+                            '[{"bucket_name": "test", '
+                            '"key": "path/to/cloudfile.fits", "region": "us-west-2"}, '
+                             '{"bucket_name": "test", '
+                             '"key": "path/to/cloudfile2.fits", "region": "us-west-2"}]}')
         dl_base_table.add_column([cloud_access_str]*4, name='cloud_access')
         out = BytesIO()
         votable = from_table(dl_base_table)
@@ -114,6 +119,7 @@ def callback(request, context):
     ) as matcher:
         yield matcher
 
+
 @pytest.fixture()
 def obscore_datalink(mocker):
     def callback(request, context):
@@ -376,31 +382,32 @@ def test_no_datalink():
     with pytest.raises(DALServiceError, match="No datalink found for record."):
         result.getdatalink()
 
+
 @pytest.mark.filterwarnings("ignore::astropy.io.votable.exceptions.E02")
 @pytest.mark.usefixtures('datalink_cloud1', 'datalink_cloud2', 'datalink_product')
 class TestJsonColumns:
-    """Tests for producing datalinks from tables containing links to
-    datalink documents.
+    """Tests for parsing JSON in Records and Results columns.
     """
 
     res = testing.create_dalresults([
-            {"name": "access_url", "datatype": "char", "arraysize": "*",
-                "ucd": "meta.ref.url"},
-            {"name": "access_format", "datatype": "char", "arraysize": "*",
-                "utype": "meta.code.mime"},
-            {"name": "cloud_access", "datatype": "char", "arraysize": "*",
-                "utype": "adhoc:cloudstorage", "ucd": "meta.ref.cloudstorage"},],
-            [("http://example.com/datalink-cloud1.xml",
-                "application/x-votable+xml;content=datalink",
-                '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}',),
-                ("http://example.com/datalink-cloud2.xml",
-                "application/x-votable+xml;content=datalink",
-                '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',),
-                 ("http://example.com/datalink.xml",
-                "application/x-votable+xml;content=datalink",
-                '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',),],
-            resultsClass=SIA2Results
-        )
+        {"name": "access_url", "datatype": "char", "arraysize": "*",
+         "ucd": "meta.ref.url"},
+        {"name": "access_format", "datatype": "char", "arraysize": "*",
+         "utype": "meta.code.mime"},
+        {"name": "cloud_access", "datatype": "char", "arraysize": "*",
+         "utype": "adhoc:cloudstorage", "ucd": "meta.ref.cloudstorage"},],
+        [("http://example.com/datalink-cloud1.xml",
+          "application/x-votable+xml;content=datalink",
+          '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}',),
+        ("http://example.com/datalink-cloud2.xml",
+         "application/x-votable+xml;content=datalink",
+         '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',),
+        ("http://example.com/datalink.xml",
+         "application/x-votable+xml;content=datalink",
+         '{"aws": {"bucket_name": "test", "key":"path/to/file2.fits", "region": "us-west-2"}}',),],
+        resultsClass=SIA2Results
+    )
+
     def test_record_w_json(self):
 
         jsontxt = '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}'
@@ -413,11 +420,14 @@ def test_extra_key(self):
         # Check that giving extra kwargs matches parameters
         jsontxt = '{"aws": {"bucket_name": "test", "key":"path/to/file1.fits", "region": "us-west-2"}}'
         parsed_json_matches0 = self.res[0].parse_json_params(json_txt=jsontxt, json_key="aws")
-        parsed_json_matches1 = self.res[0].parse_json_params(json_txt=jsontxt, json_key="aws", region="us-west-2")
+        parsed_json_matches1 = self.res[0].parse_json_params(json_txt=jsontxt,
+                                                             json_key="aws", region="us-west-2")
 
         assert parsed_json_matches0 == parsed_json_matches1
 
-        parsed_json_matches2 = self.res[0].parse_json_params(json_txt=jsontxt, json_key="aws", region="us-west-1")
+        parsed_json_matches2 = self.res[0].parse_json_params(json_txt=jsontxt,
+                                                             json_key="aws",
+                                                             region="us-west-1")
         assert len(parsed_json_matches2) == 0
 
     def test_datalink_json(self):
@@ -444,7 +454,9 @@ def test_existing_colname(self):
 
     def no_column_in_datalink(self, capsys):
         # All column guesses come back empty
-        parsed_cloud_params = self.res[1].get_cloud_params(provider="aws", colname="cloud_access", verbose=True)
+        parsed_cloud_params = self.res[1].get_cloud_params(provider="aws",
+                                                           colname="cloud_access",
+                                                           verbose=True)
         assert "No column cloud_access" in capsys
         assert parsed_cloud_params is None
 
@@ -463,4 +475,3 @@ def test_iter_datalink_json(self):
         assert parsed_json_matches[2]["record_row"] == 1
         assert parsed_json_matches[2]["datalink_row"] == 0
         assert parsed_json_matches[2]["key"] == "path/to/cloudfile2.fits"
-