Better connection problem handling in webmodels.

cameo/io.py

@@ -20,6 +20,7 @@
 from cobra.io import read_sbml_model
 import time
 import progressbar
+import requests
 from cameo.solver_based_model import SolverBasedModel, to_solver_based_model
 from cameo import webmodels
 
@@ -47,6 +48,13 @@ def load_model(path_or_handle, solver_interface=optlang.glpk_interface, sanitize
             logger.debug('%s not a file path. Querying webmodels ...' % path)
             try:
                 df = webmodels.index_models()
+            except requests.ConnectionError as e:
+                logger.error("You need to be connectedd to the internet to load an online model.")
+                raise e
+            except Exception as e:
+                logger.error("Something went wrong while looking up available webmodels.")
+                raise e
+            try:
                 index = df.query('name == "%s"' % path_or_handle).id.values[0]
                 handle = webmodels.get_sbml_file(index)
                 path = handle.name

cameo/webmodels.py

@@ -25,6 +25,9 @@
 from pandas import DataFrame
 import tempfile
 
+import logging
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
 
 class NotFoundException(Exception):
     def __init__(self, type, index, *args, **kwargs):
@@ -46,9 +49,16 @@ def index_models(host="http://darwin.di.uminho.pt/models"):
         summary of the models in the database
     """
     uri = host + "/models.json"
-    response = json.loads(requests.get(uri).text)
-    return DataFrame(response, columns=["id", "name", "doi", "author", "year", "formats", "organism", "taxonomy"])
-
+    try:
+        response = requests.get(uri)
+    except requests.ConnectionError as e:
+        logger.error("Cannot reach %s. Are you sure that you are connected to the internet?" % host)
+        raise e
+    if response.status_code == 200:
+        response = json.loads(response.text)
+        return DataFrame(response, columns=["id", "name", "doi", "author", "year", "formats", "organism", "taxonomy"])
+    else:
+        raise Exception("Could not index available models. %s returned status code %d" % (host, response.status_code))
 
 def get_sbml_file(index, host="http://darwin.di.uminho.pt/models"):
     temp = tempfile.NamedTemporaryFile()