Create get_parameters in BaseEDRProvider (#2367)

* Migrate get_parameters to base_edr

* Use get_parameters in xarray

* Fix tests

* Fix flake8

* Migrate as_list annotation

Author: webb-ben

pygeoapi/api/collection.py

@@ -400,37 +400,7 @@ def gen_collection(api, request, dataset: str,
         # TODO: translate
         LOGGER.debug('Adding EDR links')
         data['data_queries'] = {}
-        parameters = p.get_fields()
-        if parameters:
-            data['parameter_names'] = {}
-            for key, value in parameters.items():
-                p_label = value.get('title')
-                p_description = value.get('description')
-                data['parameter_names'][key] = {
-                    'id': key,
-                    'type': 'Parameter',
-                    'observedProperty': {
-                        'label': {
-                            'en': p_label
-                        }
-                    },
-                    'unit': {
-                        'label': {
-                            'en': value['title']
-                        },
-                        'symbol': {
-                            'value': value['x-ogc-unit'],
-                            'type': 'http://www.opengis.net/def/uom/UCUM/'
-                        }
-                    }
-                }
-
-                if p_description is not None:
-                    data['parameter_names'][key]['observedProperty'].update({
-                        'description': {
-                            'en': p_description
-                        }
-                    })
+        data['parameter_names'] = p.get_parameters()
 
         for qt in p.get_query_types():
             data_query = {

pygeoapi/provider/base_edr.py

@@ -105,6 +105,57 @@ def get_query_types(self):
 
         return self.query_types
 
+    def get_parameters(
+        self, parameters: set | list = [], as_list=False
+    ) -> dict | list:
+        """
+        Generate CoverageJSON parameters from provider field defintions
+
+        :param parameters: List of the subset of parameters include.
+        :param as_list: bool to return as a list of parameter definitions.
+                        GeoJSON parameters are returned as an array
+                        https://github.com/opengeospatial/ogcapi-environmental-data-retrieval/issues/633
+
+
+        :returns: A dictionary or list containing the parameter definition.
+        """
+        if not parameters:
+            parameters = set(self.fields.keys())
+
+        out_params = {}
+        for name in set(parameters):
+            conf_ = self.fields[name]
+            p_label = conf_.get('title')
+            out_params[name] = {
+                'id': name,
+                'type': 'Parameter',
+                'name': p_label,
+                'observedProperty': {
+                    'id': name,
+                    'label': {'en': p_label}
+                },
+                'unit': {
+                    'symbol': {
+                        'value': conf_['x-ogc-unit'],
+                        'type': 'http://www.opengis.net/def/uom/UCUM/'
+                    }
+                }
+            }
+
+            # Add description if available
+            p_description = conf_.get('description')
+            if p_description is not None:
+                out_params[name]['observedProperty'].update({
+                    'description': {
+                        'en': p_description
+                    }
+                })
+
+        if as_list:
+            return list(out_params.values())
+        else:
+            return out_params
+
     def query(self, **kwargs):
         """
         Extract data from collection collection

pygeoapi/provider/xarray_.py

@@ -44,6 +44,7 @@
                                     ProviderConnectionError,
                                     ProviderNoDataError,
                                     ProviderQueryError)
+from pygeoapi.provider.base_edr import BaseEDRProvider
 from pygeoapi.util import read_data
 
 LOGGER = logging.getLogger(__name__)
@@ -378,24 +379,9 @@ def gen_covjson(self, metadata, data, fields):
             })
 
         LOGGER.debug('Adding parameters')
-        for key, value in selected_fields.items():
-            parameter = {
-                'type': 'Parameter',
-                'description': {
-                    'en': value['title']
-                },
-                'unit': {
-                    'symbol': value['x-ogc-unit']
-                },
-                'observedProperty': {
-                    'id': key,
-                    'label': {
-                        'en': value['title']
-                    }
-                }
-            }
-
-            cj['parameters'][key] = parameter
+        cj['parameters'] = BaseEDRProvider.get_parameters(
+            self, selected_fields
+        )
 
         data = data.fillna(None)
 

tests/api/test_environmental_data_retrieval.py

@@ -54,7 +54,6 @@ def test_describe_collection_edr(config, api_):
     assert sst['id'] == 'SST'
     assert sst['type'] == 'Parameter'
     assert sst['observedProperty']['label']['en'] == 'SEA SURFACE TEMPERATURE'
-    assert sst['unit']['label']['en'] == 'SEA SURFACE TEMPERATURE'
     assert sst['unit']['symbol']['value'] == 'Deg C'