diff options
Diffstat (limited to 'src/Hakyll/Web/Template/Context.hs')
| -rw-r--r-- | src/Hakyll/Web/Template/Context.hs | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/src/Hakyll/Web/Template/Context.hs b/src/Hakyll/Web/Template/Context.hs index cd52eb0..a741272 100644 --- a/src/Hakyll/Web/Template/Context.hs +++ b/src/Hakyll/Web/Template/Context.hs @@ -56,6 +56,20 @@ data ContextField -------------------------------------------------------------------------------- +-- | The 'Context' monoid. Please note that the order in which you +-- compose the items is important. For example in +-- +-- > field "A" f1 <> field "A" f2 +-- +-- the first context will overwrite the second. This is especially +-- important when something is being composed with +-- 'metadataField' (or 'defaultContext'). If you want your context to be +-- overwritten by the metadata fields, compose it from the right: +-- +-- @ +-- 'metadataField' \<\> field \"date\" fDate +-- @ +-- newtype Context a = Context { unContext :: String -> Item a -> Compiler ContextField } @@ -73,11 +87,16 @@ field' key value = Context $ \k i -> if k == key then value i else empty -------------------------------------------------------------------------------- -field :: String -> (Item a -> Compiler String) -> Context a +-- | Constructs a new field in the 'Context.' +field :: String -- ^ Key + -> (Item a -> Compiler String) -- ^ Function that constructs a + -- value based on the item + -> Context a field key value = field' key (fmap StringField . value) -------------------------------------------------------------------------------- +-- | Creates a 'field' that does not depend on the 'Item' constField :: String -> String -> Context a constField key = field key . const . return @@ -108,6 +127,17 @@ mapContext f (Context c) = Context $ \k i -> do -------------------------------------------------------------------------------- +-- | A context that contains (in that order) +-- +-- 1. A @$body$@ field +-- +-- 2. Metadata fields +-- +-- 3. A @$url$@ 'urlField' +-- +-- 4. A @$path$@ 'pathField' +-- +-- 5. A @$title$@ 'titleField' defaultContext :: Context String defaultContext = bodyField "body" `mappend` @@ -124,6 +154,7 @@ teaserSeparator = "<!--more-->" -------------------------------------------------------------------------------- +-- | Constructs a 'field' that contains the body of the item. bodyField :: String -> Context String bodyField key = field key $ return . itemBody @@ -150,7 +181,7 @@ pathField key = field key $ return . toFilePath . itemIdentifier -------------------------------------------------------------------------------- --- | This title field takes the basename of the underlying file by default +-- | This title 'field' takes the basename of the underlying file by default titleField :: String -> Context a titleField = mapContext takeBaseName . pathField |