[renderAsHTML: render <script> and <style> content as #CDATA. Don't raise errors on invalid children.
jeremyn-heptane.com**20080513021307
 
 In XML, the contents of <script> and <style> are #PCDATA, but in HTML they are #CDATA. So, we unescape the contents of those tags before outputing them in HTML mode.
 
 Additionally, instead of raising errors when unexpected children are found (e.g., <img> having a child), we output the children anyway. Since renderAsHTML does not do any other 
 validation, this seems in line with the way the rest of the function works. If you want validation, it is better to run it through a separate HTML validator.
 
 See these threads for more information:
 
 http://groups.google.com/group/haskell-server-pages/browse_thread/thread/70216bd746ae1ec4
 http://groups.google.com/group/haskell-server-pages/browse_thread/thread/171a1e2372b97020
 
] {
hunk ./src/HSP/HTML.hs 27
+import HSP.XML.PCDATA(unescape)
hunk ./src/HSP/HTML.hs 32
--- FIXME: what to do with xmlns in html tag
--- TODO: add strict mode which runs a validator (that probably belongs in the function which calls renderAsHTML)
--- FIXME: elements which forbid and end tag, should perhaps not contain children ?
hunk ./src/HSP/HTML.hs 33
--- NOTE: this can throw errors, but you have to be in the IO monad to
+-- Error Handling:
+--
+-- Some tags (such as img) can not contain children in HTML. However,
+-- there is nothing to stop the caller from passing in XML which
+-- contains an img tag with children. There are three basic ways to
+-- handle this:
+--
+--  1. drop the bogus children silently
+--  2. call 'error' / raise an exception
+--  3. render the img tag with children -- even though it is invalid
+--
+-- Currently we are taking approach #3, since no other attempts to
+-- validate the data are made in this function. Instead, you can run
+-- the output through a full HTML validator to detect the errors.
+--
+-- #1 seems like a poor choice, since it makes is easy to overlook the
+-- fact that data went missing.
+--
+-- We could raising errors, but you have to be in the IO monad to
hunk ./src/HSP/HTML.hs 68
-renderAsHTML' n (Element name@(Nothing,nm) attrs children) 
+renderAsHTML' n elm@(Element name@(Nothing,nm) attrs children) 
hunk ./src/HSP/HTML.hs 79
+    | nm == "script"    = renderTagCDATA children
+    | nm == "style"     = renderTagCDATA children
hunk ./src/HSP/HTML.hs 83
-      renderTagEmpty cs = error $ (filter ( /= '\n') (renderTag Open 0 name attrs " should be empty, but contains children:")) ++ "\n" ++ 
-                            (foldr (renderAsHTML' 0) "" cs)
-renderAsHTML' n (Element name attrs children) =
+      renderTagEmpty _ = renderElement n elm -- ^ this case should not happen in valid HTML
+      renderTagCDATA :: Children -> ShowS
+      renderTagCDATA children =
+        let open  = renderTag Open n name attrs 
+            cs    = renderChildrenCDATA 0 children 
+            close = renderTag Close n name []
+        in
+          open . cs .close
+      renderChildrenCDATA :: Int -> Children -> ShowS
+      renderChildrenCDATA n' cs = foldl (.) id $ map (renderChildCDATA (n'+2)) cs
+      renderChildCDATA n (CDATA cd) = showString (unescape cd)
+      renderChildCDATA n e = renderElement n e  -- ^ this case should not happen in valid HTML
+renderAsHTML' n e = renderElement n e
+
+renderElement n (Element name attrs children) =
hunk ./src/HSP/HTML.hs 105
-
-                
hunk ./src/HSP/HTML.hs 131
-
-
-
}