Bugfix/36 dataset extractor fails empty dataset

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## Unreleased
 
+### Fixed
+- extractor would fail on empty dataset download [#36](https://github.com/clowder-framework/pyclowder/issues/36)
+
 ### Added
 - ability to set the heartbeat for an extractractor [#42](https://github.com/clowder-framework/pyclowder/issues/42)
 

pyclowder/connectors.py

@@ -293,6 +293,9 @@ def _download_file_metadata(self, host, secret_key, fileid, filepath):
         return (md_dir, md_file)
 
     def _prepare_dataset(self, host, secret_key, resource):
+        logger = logging.getLogger(__name__)
+
+        file_paths = []
         located_files = []
         missing_files = []
         tmp_files_created = []
@@ -354,10 +357,13 @@ def _prepare_dataset(self, host, secret_key, resource):
 
         # If we didn't find any files locally, download dataset .zip as normal
         else:
-            inputzip = pyclowder.datasets.download(self, host, secret_key, resource["id"])
-            file_paths = pyclowder.utils.extract_zip_contents(inputzip)
-            tmp_files_created += file_paths
-            tmp_files_created.append(inputzip)
+            try:
+                inputzip = pyclowder.datasets.download(self, host, secret_key, resource["id"])
+                file_paths = pyclowder.utils.extract_zip_contents(inputzip)
+                tmp_files_created += file_paths
+                tmp_files_created.append(inputzip)
+            except Exception as e:
+                logger.exception("No files found and download failed")
 
         return (file_paths, tmp_files_created, tmp_dirs_created)