Implement bug #3359: Make markdown processing of text files optional.

src/calibre/ebooks/oeb/base.py

@@ -934,7 +934,7 @@ class Manifest(object):
 
             self.oeb.log.debug('Converting', self.href, '...')
 
-            from calibre.ebooks.txt.processor import txt_to_markdown
+            from calibre.ebooks.txt.processor import convert_markdown
 
             title = self.oeb.metadata.title
             if title:
@@ -942,7 +942,7 @@ class Manifest(object):
             else:
                 title = _('Unknown')
 
-            return self._parse_xhtml(txt_to_markdown(data, title))
+            return self._parse_xhtml(convert_markdown(data, title))
 
 
         def _parse_css(self, data):

src/calibre/ebooks/pdb/palmdoc/reader.py

@@ -13,8 +13,8 @@ import struct
 
 from calibre.ebooks.compression.palmdoc import decompress_doc
 from calibre.ebooks.pdb.formatreader import FormatReader
-from calibre.ebooks.txt.processor import opf_writer
-from calibre.ebooks.txt.processor import txt_to_markdown
+from calibre.ebooks.txt.processor import convert_basic, separate_paragraphs, \
+    opf_writer
 
 class HeaderRecord(object):
     '''
@@ -62,7 +62,9 @@ class Reader(FormatReader):
             txt += self.decompress_text(i)
 
         self.log.info('Converting text to OEB...')
-        html = txt_to_markdown(txt, single_line_paras=self.single_line_paras)
+        if self.single_line_paras:
+            txt = separate_paragraphs(txt)
+        html = convert_basic(txt)
         with open(os.path.join(output_dir, 'index.html'), 'wb') as index:
             index.write(html.encode('utf-8'))
 

src/calibre/ebooks/pdb/ztxt/reader.py

@@ -12,7 +12,8 @@ import os, struct, zlib
 
 from calibre.ebooks.pdb.formatreader import FormatReader
 from calibre.ebooks.pdb.ztxt import zTXTError
-from calibre.ebooks.txt.processor import txt_to_markdown, opf_writer
+from calibre.ebooks.txt.processor import convert_basic, separate_paragraphs, \
+    opf_writer
 
 SUPPORTED_VERSION = (1, 40)
 
@@ -77,7 +78,9 @@ class Reader(FormatReader):
             txt += self.decompress_text(i)
 
         self.log.info('Converting text to OEB...')
-        html = txt_to_markdown(txt, single_line_paras=self.single_line_paras)
+        if self.single_line_paras:
+            txt = separate_paragraphs(txt)
+        html = convert_basic(txt)
         with open(os.path.join(output_dir, 'index.html'), 'wb') as index:
             index.write(html.encode('utf-8'))
                         

src/calibre/ebooks/txt/input.py

@@ -7,7 +7,8 @@ __docformat__ = 'restructuredtext en'
 import os
 
 from calibre.customize.conversion import InputFormatPlugin, OptionRecommendation
-from calibre.ebooks.txt.processor import txt_to_markdown
+from calibre.ebooks.txt.processor import convert_basic, convert_markdown, \
+    separate_paragraphs
 
 class TXTInput(InputFormatPlugin):
 
@@ -21,6 +22,8 @@ class TXTInput(InputFormatPlugin):
             help=_('Normally calibre treats blank lines as paragraph markers. '
                 'With this option it will assume that every line represents '
                 'a paragraph instead.')),
+        OptionRecommendation(name='markdown', recommended_value=False,
+            help=_('Run the text input though the markdown processor.')),
     ])
 
     def convert(self, stream, options, file_ext, log,
@@ -31,12 +34,18 @@ class TXTInput(InputFormatPlugin):
         log.debug('Reading text from file...')
         txt = stream.read().decode(ienc, 'replace')
 
+        if options.single_line_paras:
+            txt = separate_paragraphs(txt)
+
+        if options.markdown:
             log.debug('Running text though markdown conversion...')
             try:
-            html = txt_to_markdown(txt, single_line_paras=options.single_line_paras)
+                html = convert_markdown(txt)
             except RuntimeError:
                 raise ValueError('This txt file has malformed markup, it cannot be'
                     'converted by calibre. See http://daringfireball.net/projects/markdown/syntax')
+        else:
+            html = convert_basic(txt)
 
         from calibre.customize.ui import plugin_for_input_format
         html_input = plugin_for_input_format('html')

src/calibre/ebooks/txt/processor.py

@@ -5,6 +5,7 @@ Read content from txt file.
 '''
 
 import os
+import re
 
 from calibre.ebooks.markdown import markdown
 from calibre.ebooks.metadata.opf2 import OPFCreator
@@ -13,18 +14,25 @@ __license__   = 'GPL v3'
 __copyright__ = '2009, John Schember <john@nachtimwald.com>'
 __docformat__ = 'restructuredtext en'
 
-def txt_to_markdown(txt, title='', single_line_paras=False):
-    if single_line_paras:
-        txt = txt.replace('\r\n', '\n')
-        txt = txt.replace('\r', '\n')
-        txt = txt.replace('\n', '\n\n')
+HTML_TEMPLATE = u'<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"/><title>%s</title></head><body>%s</body></html>'
+
+def convert_basic(txt, title=''):
+    lines = []
+    for line in txt.splitlines():
+        lines.append('<p>%s</p>' % line)
+    return HTML_TEMPLATE % (title, '\n'.join(lines))
+
+def convert_markdown(txt, title=''):
     md = markdown.Markdown(
         extensions=['footnotes', 'tables', 'toc'],
         safe_mode=False,)
-    html = u'<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"/><title>%s</title></head><body>%s</body></html>' % (title,
-        md.convert(txt))
+    return HTML_TEMPLATE % (title, md.convert(txt))
 
-    return html
+def separate_paragraphs(txt):
+    txt = txt.replace('\r\n', '\n')
+    txt = txt.replace('\r', '\n')
+    txt = re.sub(u'(?<=.)\n(?=.)', u'\n\n', txt)
+    return txt
 
 def opf_writer(path, opf_name, manifest, spine, mi):
     opf = OPFCreator(path, mi)