pulled global functions out of views file and put them in separate utils.py

bookshare/trades/utils.py

+import requests
+from .models import Flag, Rating, BidFlag
+
+
+# pulls worldcat metadata from ISBNs
+def ISBNMetadata(standardISBN):
+    # passing in numbers starting with 0 throws "SyntaxError: invalid token"
+    url = "http://xisbn.worldcat.org/webservices/xid/isbn/" +\
+          str(standardISBN) +\
+          "?method=getMetadata&format=json&fl=title,year,author,ed"
+
+    # In case the API fails to return, simply return None.
+    try:
+        metadata = requests.get(url, timeout=3)
+    except requests.ConnectionError:
+        return None
+
+    # format into a dictionary
+    dejson = metadata.json()
+    try:
+        metadataDict = dejson.get('list')
+        return metadataDict[0]
+    except:
+        return None
+
+
+# flagging
+# you can only flag a listing once...
+def can_flag(flagger, listing):
+    user_flag_num = Flag.objects.filter(flagger=flagger,
+                                        listing=listing).count()
+    # we're assuming that this isn't going to go over 1
+    if user_flag_num:
+        return False
+    else:
+        return True
+
+
+def can_flag_bid(flagger, bid):
+    user_flag_num = BidFlag.objects.filter(flagger=flagger,
+                                           bid=bid).count()
+    if user_flag_num:
+        return False
+    else:
+        return True
+
+
+# get the listing's slug to pass to the create flag page
+def flag_slug(flagger, listing):
+    if not can_flag(flagger, listing):
+        return Flag.objects.get(flagger=flagger, listing=listing).slug
+    else:
+        return None
+
+
+def bid_flag_slug(flagger, bid):
+    if not can_flag_bid(flagger, bid):
+        return BidFlag.objects.get(flagger=flagger, bid=bid).slug
+    else:
+        return None
+
+
+# rating
+# (basically) duplicated code!!!
+def can_rate(rater, listing):
+    user_rate_num = Rating.objects.filter(rater=rater,
+                                          listing=listing).count()
+    # we're assuming that this isn't going to go over 1
+    if user_rate_num:
+        return False
+    else:
+        return True