Add a --preprocess-html option

src/calibre/customize/conversion.py

@@ -149,6 +149,18 @@ class InputFormatPlugin(Plugin):
         '''
         raise NotImplementedError()
 
+    def preprocess_html(self, html):
+        '''
+        This method is called by the conversion pipeline on all HTML before it
+        is parsed. It is meant to be used to do any required preprocessing on
+        the HTML, like removing hard line breaks, etc.
+
+        :param html: A unicode string
+        :return: A unicode string
+        '''
+        return html
+
+
     def convert(self, stream, options, file_ext, log, accelerators):
         '''
         This method must be implemented in sub-classes. It must return

src/calibre/ebooks/conversion/cli.py

@@ -129,6 +129,7 @@ def add_pipeline_options(parser, plumber):
                       'dont_split_on_page_breaks', 'chapter', 'chapter_mark',
                       'prefer_metadata_cover', 'remove_first_image',
                       'insert_metadata', 'page_breaks_before',
+                      'preprocess_html',
                   ]
                   ),
 

src/calibre/ebooks/conversion/plumber.py

@@ -312,6 +312,14 @@ OptionRecommendation(name='insert_metadata',
             )
         ),
 
+OptionRecommendation(name='preprocess_html',
+        recommended_value=False, level=OptionRecommendation.LOW,
+        help=_('Attempt to detect and correct hard line breaks and other '
+            'problems in the source file. This may make things worse, so use '
+            'with care.'
+            )
+        ),
+
 
 OptionRecommendation(name='read_metadata_from_opf',
             recommended_value=None, level=OptionRecommendation.LOW,
@@ -580,7 +588,8 @@ OptionRecommendation(name='list_recipes',
             self.log('Debug input called, aborting the rest of the pipeline.')
             return
         if not hasattr(self.oeb, 'manifest'):
-            self.oeb = create_oebbook(self.log, self.oeb, self.opts)
+            self.oeb = create_oebbook(self.log, self.oeb, self.opts,
+                    self.input_plugin)
         pr = CompositeProgressReporter(0.34, 0.67, self.ui_reporter)
         pr(0., _('Running transforms on ebook...'))
 
@@ -652,12 +661,13 @@ OptionRecommendation(name='list_recipes',
                 self.opts, self.log)
         self.ui_reporter(1.)
 
-def create_oebbook(log, path_or_stream, opts, reader=None):
+def create_oebbook(log, path_or_stream, opts, input_plugin, reader=None):
     '''
     Create an OEBBook.
     '''
     from calibre.ebooks.oeb.base import OEBBook
-    html_preprocessor = HTMLPreProcessor()
+    html_preprocessor = HTMLPreProcessor(input_plugin.preprocess_html,
+            opts.preprocess_html)
     oeb = OEBBook(log, html_preprocessor=html_preprocessor,
             pretty_print=opts.pretty_print)
     # Read OEB Book into OEBBook

src/calibre/ebooks/conversion/preprocess.py

@@ -151,6 +151,9 @@ class HTMLPreProcessor(object):
                      (re.compile('<span[^><]*?id=subtitle[^><]*?>(.*?)</span>', re.IGNORECASE|re.DOTALL),
                       lambda match : '<h3 class="subtitle">%s</h3>'%(match.group(1),)),
                      ]
+    def __init__(self, input_plugin_preprocess, plugin_preprocess):
+        self.input_plugin_preprocess = input_plugin_preprocess
+        self.plugin_preprocess = plugin_preprocess
 
     def is_baen(self, src):
         return re.compile(r'<meta\s+name="Publisher"\s+content=".*?Baen.*?"',
@@ -192,5 +195,8 @@ class HTMLPreProcessor(object):
 
         html = XMLDECL_RE.sub('', html)
 
+        if self.plugin_preprocess:
+            html = self.input_plugin_preprocess(html)
+
         return html
 

src/calibre/ebooks/html/input.py

@@ -288,7 +288,7 @@ class HTMLInput(InputFormatPlugin):
             return opfpath
 
         from calibre.ebooks.conversion.plumber import create_oebbook
-        oeb = create_oebbook(log, opfpath, opts)
+        oeb = create_oebbook(log, opfpath, opts, self)
 
         from calibre.ebooks.oeb.transforms.package import Package
         Package(os.getcwdu())(oeb, opts)

src/calibre/ebooks/lit/input.py

@@ -19,6 +19,6 @@ class LITInput(InputFormatPlugin):
                 accelerators):
         from calibre.ebooks.lit.reader import LitReader
         from calibre.ebooks.conversion.plumber import create_oebbook
-        return create_oebbook(log, stream, options, reader=LitReader)
+        return create_oebbook(log, stream, options, self, reader=LitReader)
 
 

src/calibre/ebooks/oeb/base.py

@@ -1506,7 +1506,7 @@ class OEBBook(object):
     COVER_OBJECT_XP = XPath('h:body//h:object[@data][position() = 1]')
 
     def __init__(self, logger,
-            html_preprocessor=HTMLPreProcessor(),
+            html_preprocessor,
             css_preprocessor=CSSPreProcessor(),
             encoding='utf-8', pretty_print=False):
         """Create empty book.  Arguments: