Move resource embedding into HTML writer [API change]

This adds a new field `writerEmbedResources` to the `WriterOptions`
type. It is set to `False` by default.

The field is named `embed_resources` in Lua.

Author: tarleb

doc/lua-filters.md

@@ -2132,6 +2132,9 @@ Fields:
 :   How to obfuscate emails -- one of 'none', 'references', or
     'javascript' (string)
 
+`embed_resources`
+:   Whether resources should be embedded in HTML output (boolean)
+
 `epub_chapter_level`
 :   Header level for chapters, i.e., how the document is split
     into separate files (integer)

pandoc-lua-engine/src/Text/Pandoc/Lua/Marshal/WriterOptions.hs

@@ -80,6 +80,11 @@ typeWriterOptions = deftype "WriterOptions"
     (pushViaJSON, writerEmailObfuscation)
     (peekViaJSON, \opts x -> opts{ writerEmailObfuscation = x })
 
+  , property "embed_resources"
+    "Whether resources should be embedded in HTML output"
+    (pushViaJSON, writerEmbedResources)
+    (peekViaJSON, \opts x -> opts{ writerEmbedResources = x })
+
   , property "split_level"
     "Level at which EPUB or chunked HTML documents are split into files"
     (pushIntegral, writerSplitLevel)

pandoc-lua-engine/test/lua/module/globals.lua

@@ -23,6 +23,9 @@ return {
     test('email_obfuscation', function ()
       assert.are_equal(type(PANDOC_WRITER_OPTIONS.email_obfuscation), 'string')
     end),
+    test('embed_resources', function ()
+      assert.are_equal(type(PANDOC_WRITER_OPTIONS.embed_resources), 'boolean')
+    end),
     test('split_level', function ()
       assert.are_equal(type(PANDOC_WRITER_OPTIONS.split_level), 'number')
     end),

src/Text/Pandoc/App.hs

@@ -65,7 +65,6 @@ import Text.Pandoc.Filter (Filter (JSONFilter, LuaFilter), Environment (..),
 import qualified Text.Pandoc.Format as Format
 import Text.Pandoc.PDF (makePDF)
 import Text.Pandoc.Scripting (ScriptingEngine (..), CustomComponents(..))
-import Text.Pandoc.SelfContained (makeSelfContained)
 import Text.Pandoc.Shared (tshow)
 import Text.Pandoc.URI (isURI)
 import Text.Pandoc.Writers.Shared (lookupMetaString)
@@ -329,10 +328,7 @@ convertWithOpts' scriptingEngine istty datadir opts = do
                     | standalone = t
                     | T.null t || T.last t /= '\n' = t <> T.singleton '\n'
                     | otherwise = t
-              textOutput <- ensureNl <$> f writerOptions doc
-              if (optSelfContained opts || optEmbedResources opts) && htmlFormat format
-                 then TextOutput <$> makeSelfContained textOutput
-                 else return $ TextOutput textOutput
+              TextOutput . ensureNl <$> f writerOptions doc
   reports <- getLog
   return (output, reports)
 

src/Text/Pandoc/App/OutputSettings.hs

@@ -263,6 +263,8 @@ optToOutputSettings scriptingEngine opts = do
         , writerSyntaxMap        = syntaxMap
         , writerPreferAscii      = optAscii opts
         , writerLinkImages       = optLinkImages opts
+        , writerEmbedResources   = optEmbedResources opts ||
+                                   optSelfContained opts
         }
   return $ OutputSettings
     { outputFormat = format

src/Text/Pandoc/Options.hs

@@ -326,6 +326,7 @@ data WriterOptions = WriterOptions
   , writerSyntaxMap         :: SyntaxMap
   , writerPreferAscii       :: Bool           -- ^ Prefer ASCII representations of characters when possible
   , writerLinkImages        :: Bool           -- ^ Use links rather than embedding ODT images
+  , writerEmbedResources    :: Bool           -- ^ Embed resources in HTML
   } deriving (Show, Data, Typeable, Generic)
 
 instance Default WriterOptions where
@@ -365,6 +366,7 @@ instance Default WriterOptions where
                       , writerSyntaxMap        = defaultSyntaxMap
                       , writerPreferAscii      = False
                       , writerLinkImages       = False
+                      , writerEmbedResources   = False
                       }
 
 instance HasSyntaxExtensions WriterOptions where

src/Text/Pandoc/Writers/HTML.hs

@@ -55,6 +55,7 @@ import Text.Pandoc.Highlighting (formatHtmlBlock, formatHtml4Block,
                  formatHtmlInline, highlight, styleToCss)
 import Text.Pandoc.ImageSize
 import Text.Pandoc.Options
+import Text.Pandoc.SelfContained (makeSelfContained)
 import Text.Pandoc.Shared
 import Text.Pandoc.Slides
 import Text.Pandoc.Templates (renderTemplate)
@@ -230,9 +231,12 @@ writeHtmlString' st opts d = do
   let colwidth = case writerWrapText opts of
                     WrapAuto -> Just (writerColumns opts)
                     _ -> Nothing
-  (if writerPreferAscii opts
-      then toEntities
-      else id) <$>
+  (if writerEmbedResources opts
+   then makeSelfContained
+   else pure) =<<
+    (if writerPreferAscii opts
+     then toEntities
+     else id) <$>
     case writerTemplate opts of
        Nothing -> return $
          case colwidth of