only include source path element in url when multiple sources

cellxgene_gateway/flask_util.py

@@ -7,9 +7,27 @@
 # OR CONDITIONS OF ANY KIND, either express or implied. See the License for
 # the specific language governing permissions and limitations under the License.
 
-from flask import request
+from flask import request, url_for
 
 
 def querystring():
     qs = request.query_string.decode()
     return f"?{qs}" if len(qs) > 0 else ""
+
+
+include_source_in_url = False
+
+
+def url(endpoint, descriptor, source_name):
+    if include_source_in_url:
+        return url_for(endpoint, source_name=source_name, path=descriptor)
+    else:
+        return url_for(endpoint, path=descriptor)
+
+
+def view_url(descriptor, source_name):
+    return url("do_view", descriptor, source_name)
+
+
+def relaunch_url(descriptor, source_name):
+    return url("do_relaunch", descriptor, source_name)