Allow "TBA" laps in TSN.XML.AutoRacingSchedule.

[dead/htsn-import.git] / src / Xml.hs

diff --git a/src/Xml.hs b/src/Xml.hs
index 5c846648a85d8a2f7b267db22b6b9b200dc67d78..d4ea4679cef1bafc974e7d9eede7249b39957491 100644 (file)
--- a/src/Xml.hs
+++ b/src/Xml.hs
@@ -4,15 +4,17 @@
 -- | General XML stuff.
 --
 module Xml (
+  Child(..),
   DtdName(..),
   FromXml(..),
   FromXmlFk(..),
-  FromXmlFkTeams(..),
   ToDb(..),
   parse_opts,
+  parse_opts_novalidate,
   pickle_unpickle,
   unpickleable,
   unsafe_read_document,
+  unsafe_read_invalid_document,
   unsafe_unpickle )
 where
 
@@ -38,9 +40,6 @@ import Text.XML.HXT.Core (
   yes )
 
 
--- Local imports.
-import TSN.Team ( Team(..) )
-
 
 -- | Common associated type shared by 'FromXml' and 'FromXmlFk'. This
 --   basically just forces the client to define the \"database
@@ -66,37 +65,29 @@ class (ToDb a) => FromXml a where
   from_xml :: a -> Db a
 
 
--- | Some database types cannot be constructed from the XML type
---   alone; they must be supplied a foreign key to a parent object
---   first. Members of this class can be converted from an XML
---   representation to a database representation in this manner.
+-- | A class for XML representations which are children of other
+--   elements. The foal is to associate a child XML element with its
+--   parent element's database type. This is required to construct the
+--   database analogue of @a@ in 'FromXmlFk'.
 --
-class (ToDb a) => FromXmlFk a where
+class Child a where
   -- | The type of our parent object, i.e. to the type to whom our
   --   foreign key will point.
   type Parent a :: *
 
+
+-- | Some database types cannot be constructed from the XML type
+--   alone; they must be supplied a foreign key to a parent object
+--   first. Members of this class can be converted from an XML
+--   representation to a database representation in this manner.
+--
+class (Child a, ToDb a) => FromXmlFk a where
   -- | The function that produces a @Db a@ out of a foreign key and an
   --   @a@. The parameter order makes it easier to map this function
   --   over a bunch of things.
   from_xml_fk :: DefaultKey (Parent a) -> a -> Db a
 
 
--- | A further refinement of 'FromXmlFk'. These types need not only a
---   foreign key to a parent in order to make the XML -> DB
---   conversion, but also two foreign keys to away/home teams (as
---   represented in "TSN.Team").
---
-class (ToDb a) => FromXmlFkTeams a where
-  -- | The function that produces a @Db a@ out of a parent foreign
-  -- key, two team foreign keys, and an @a@. The parameter order makes
-  -- it easier to map this function over a bunch of things.
-  from_xml_fk_teams :: DefaultKey (Parent a)
-                    -> DefaultKey Team -- ^ The away team FK
-                    -> DefaultKey Team -- ^ The home team FK
-                    -> a
-                    -> Db a
-
 
 -- | Represents the DTD filename (\"SYSTEM\") part of the DOCTYPE
 --   definition.
@@ -108,8 +99,14 @@ newtype DtdName = DtdName String
 --
 parse_opts :: SysConfigList
 parse_opts = [ withRemoveWS yes,
-               withSubstDTDEntities no,
-               withValidate no ]
+               withSubstDTDEntities no ]
+
+-- | Like 'parse_opts' except we don't validate the document against
+--   its DTD. This is useful when we need to parse a document that we
+--   /know/ is invalid so that we can deliver a better error message.
+--
+parse_opts_novalidate :: SysConfigList
+parse_opts_novalidate = (withValidate no) : parse_opts
 
 
 -- | Given an @unpickler@ and a @filepath@, attempt to unpickle the
@@ -185,3 +182,10 @@ unsafe_unpickle filepath unpickler =
 unsafe_read_document :: FilePath -> IO XmlTree
 unsafe_read_document filepath =
   fmap head $ runX $ readDocument parse_opts filepath
+
+-- | The same as 'unsafe_read_document', except it allows you to read
+--   documents which don't validate against their DTDs.
+--
+unsafe_read_invalid_document :: FilePath -> IO XmlTree
+unsafe_read_invalid_document filepath =
+  fmap head $ runX $ readDocument parse_opts_novalidate filepath