Fix TNS Catalog search and add help text

tom_catalogs/forms.py

@@ -7,7 +7,26 @@ class CatalogQueryForm(forms.Form):
     Form used for catalog harvesters ``CatalogQueryView``.
     """
     term = forms.CharField()
-    service = forms.ChoiceField(choices=lambda: [(key, key) for key in get_service_classes().keys()])
+    catalog_choices = []
+    service = forms.ChoiceField(choices=[])
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['service'].choices = self.get_catalog_choices()
+
+    def get_catalog_choices(self):
+        """
+        Returns a list of catalog choices for the form including Help text if available
+        :return:
+        """
+        catalog_choices = []
+        for catalog_name in get_service_classes().keys():
+            if getattr(get_service_classes()[catalog_name], "help_text", None):
+                catalog_choices.append(
+                    (catalog_name, f'{catalog_name} -- {get_service_classes()[catalog_name].help_text}'))
+            else:
+                catalog_choices.append((catalog_name, catalog_name))
+        return catalog_choices
 
     def get_target(self):
         """

tom_catalogs/harvesters/jplhorizons.py

@@ -11,6 +11,7 @@ class JPLHorizonsHarvester(AbstractHarvester):
     """
 
     name = 'JPL Horizons'
+    help_text = 'Query the JPL Horizons Minor Body catalog.'
 
     def query(self, term, location=None, start=None, end=None, step=None):
         if all((start, end, step)):

tom_catalogs/harvesters/tns.py

@@ -13,11 +13,16 @@
 TNS_URL = 'https://www.wis-tns.org'
 
 try:
+    # Check if there is an API key in the HARVESTERS section of settings.py
     TNS_CREDENTIALS = settings.HARVESTERS['TNS']
 except (AttributeError, KeyError):
-    TNS_CREDENTIALS = {
-        'api_key': ''
-    }
+    try:
+        # Otherwise, check if there is an API key in the BROKERS section of settings.py
+        TNS_CREDENTIALS = settings.BROKERS['TNS']
+    except (AttributeError, KeyError):
+        TNS_CREDENTIALS = {
+            'api_key': ''
+        }
 
 
 def get(term):
@@ -31,12 +36,24 @@ def get(term):
     get_data = [('api_key', (None, TNS_CREDENTIALS['api_key'])),
                 ('data', (None, json.dumps(json_file)))]
 
-    response = requests.post(get_url, files=get_data, headers=TNSBroker.tns_headers())
-    response_data = json.loads(response.text)
-
-    if 400 <= response_data.get('id_code') <= 403:
-        raise ImproperCredentialsException('TNS: ' + str(response_data.get('id_message')))
-
+    try:
+        response = requests.post(get_url, files=get_data, headers=TNSBroker.tns_headers())
+        response_data = json.loads(response.text)
+
+        if 400 <= response_data.get('id_code') <= 403:
+            raise ImproperCredentialsException('TNS: ' + str(response_data.get('id_message')))
+    except AttributeError:
+        raise ImproperCredentialsException(f"TNS Catalog Search. This requires TNS Broker configuration. "
+                                           f"Please see {TNSBroker.help_url} for more information")
+
+    reply = response_data['data']['reply']
+    # If TNS succeeds in finding an object, it returns a reply containing the `objname`.
+    # If TNS fails to find the object, it returns a reply in the form:
+    # {'name': {'110': {'message': 'No results found.', 'message_id': 110}},
+    # 'objid': {'110': {'message': 'No results found.', 'message_id': 110}}}
+    # In this case, we return None
+    if not reply.get('objname', None):
+        return None
     return response_data['data']['reply']
 
 
@@ -47,6 +64,7 @@ class TNSHarvester(AbstractHarvester):
     """
 
     name = 'TNS'
+    help_text = 'Requires object name without prefix.'
 
     def query(self, term):
         self.catalog_data = get(term)

tom_catalogs/tests/tests.py

@@ -7,6 +7,7 @@
 
 class TestHarvester(AbstractHarvester):
     name = 'TEST'
+    help_text = "This is a test harvester."
 
     def query(self, term):
         if term == 'notfound':
@@ -37,6 +38,7 @@ def setUp(self):
     def test_service_available(self):
         response = self.client.get(reverse('tom_catalogs:query'))
         self.assertContains(response, TestHarvester.name)
+        self.assertContains(response, TestHarvester.help_text)
 
     def test_do_search(self):
         data = {'term': 'atarget', 'service': 'TEST'}