1 files changed, 31 insertions, 0 deletions
diff --git a/gsxws/utils.py b/gsxws/utils.py
new file mode 100644
index 0000000..9d71e83
--- /dev/null
+++ b/gsxws/utils.py
@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+
+import re
+import tempfile
+import requests
+
+
+def fetch_url(url):
+    """Downloads acceptable URL to temporary file
+    """
+    ext = None
+    ALLOWED = ['jpg', 'jpeg', 'png', 'pdf', 'gif',]
+
+    try:
+        ext = re.search(r'\.([a-zA-Z]{3,})$', url).group(1)
+    except AttributeError:
+        raise ValueError('Cannot determine file extension of URL %s' % url)
+
+    ext = ext.lower()
+
+    if ext not in ALLOWED:
+        raise ValueError('File extension should be one of %s, not %s' % (', '.join(ALLOWED), ext))
+
+    try:
+        resp = requests.get(url)
+    except Exception as e:
+        raise Exception('Failed to fetch URL: %s' % e)
+    
+    with tempfile.NamedTemporaryFile(delete=False, suffix='.' + ext) as fp:
+        fp.write(resp.content)
+        return fp.name