Add a has_only_single_sms function to TSN.XML.News.

[dead/htsn-import.git] / src / TSN / XML / News.hs

diff --git a/src/TSN/XML/News.hs b/src/TSN/XML/News.hs
index 3f9fef5375b58ec440eed4c041985871ed0d6300..10c51956fa20c23a16ff45b3469bc477aac078a7 100644 (file)
--- a/src/TSN/XML/News.hs
+++ b/src/TSN/XML/News.hs
@@ -11,6 +11,7 @@
 --
 module TSN.XML.News (
   dtd,
+  has_only_single_sms,
   pickle_message,
   -- * Tests
   news_tests,
@@ -45,6 +46,16 @@ import Test.Tasty ( TestTree, testGroup )
 import Test.Tasty.HUnit ( (@?=), testCase )
 import Text.XML.HXT.Core (
   PU,
+  XmlTree,
+  (/>),
+  (>>>),
+  addNav,
+  descendantAxis,
+  filterAxis,
+  followingSiblingAxis,
+  hasName,
+  remNav,
+  runLA,
   xp13Tuple,
   xpAttr,
   xpElem,
@@ -69,6 +80,7 @@ import Xml (
   ToDb(..),
   pickle_unpickle,
   unpickleable,
+  unsafe_read_document,
   unsafe_unpickle )
 
 
@@ -202,8 +214,37 @@ data News_Location = News_Location
 
 
 
+
+-- | Some newsxml documents contain two \<SMS\> elements in a row,
+--   violating the DTD. The second one has always been empty, but it's
+--   irrelevant: we can't parse these, and would like to detect them
+--   in order to report the fact that the busted document is
+--   unsupported.
+--
+--   This function detects whether two \<SMS\> elements appear in a
+--   row, as siblings.
+--
+has_only_single_sms :: XmlTree -> Bool
+has_only_single_sms xmltree =
+    case elements of
+    [] -> True
+    _  -> False
+  where
+    parse :: XmlTree -> [XmlTree]
+    parse = runLA $  hasName "/"
+                  /> hasName "message"
+                  >>> addNav
+                  >>> descendantAxis
+                  >>> filterAxis (hasName "SMS")
+                  >>> followingSiblingAxis
+                  >>> remNav
+                  >>> hasName "SMS"
+
+    elements = parse xmltree
+
+
 --
--- Database code
+-- * Database code
 --
 
 -- | Define 'dbmigrate' and 'dbimport' for 'Message's. The import is
@@ -407,7 +448,8 @@ news_tests =
     [ test_news_fields_have_correct_names,
       test_on_delete_cascade,
       test_pickle_of_unpickle_is_identity,
-      test_unpickle_succeeds ]
+      test_unpickle_succeeds,
+      test_sms_detected_correctly ]
 
 
 -- | Make sure our codegen is producing the correct database names.
@@ -506,3 +548,22 @@ test_on_delete_cascade = testGroup "cascading delete tests"
                   count_e <- countAll e
                   return $ count_a + count_b + count_c + count_d + count_e
       actual @?= expected
+
+
+-- | We want to make sure the single-SMS documents and the multi-SMS
+--   documents are identified correctly.
+--
+test_sms_detected_correctly :: TestTree
+test_sms_detected_correctly =
+  testGroup "newsxml SMS count determined correctly"
+    [ check "test/xml/newsxml.xml"
+            "single SMS detected correctly"
+            True,
+      check "test/xml/newsxml-multiple-sms.xml"
+            "multiple SMS detected correctly"
+            False ]
+  where
+    check path desc expected = testCase desc $ do
+      xmltree <- unsafe_read_document path
+      let actual = has_only_single_sms xmltree
+      actual @?= expected