Current File : //usr/lib/calibre/calibre/ebooks/txt/txtml.py
__license__ = 'GPL 3'
__copyright__ = '2009, John Schember <john@nachtimwald.com>'
__docformat__ = 'restructuredtext en'
'''
Transform OEB content into plain text
'''
import re
from lxml import etree
from polyglot.builtins import string_or_bytes
BLOCK_TAGS = [
'div',
'p',
'h1',
'h2',
'h3',
'h4',
'h5',
'h6',
'li',
'tr',
]
BLOCK_STYLES = [
'block',
]
HEADING_TAGS = [
'h1',
'h2',
'h3',
'h4',
'h5',
'h6',
]
SPACE_TAGS = [
'td',
'br',
]
class TXTMLizer:
def __init__(self, log):
self.log = log
def extract_content(self, oeb_book, opts):
self.log.info('Converting XHTML to TXT...')
self.oeb_book = oeb_book
self.opts = opts
self.toc_titles = []
self.toc_ids = []
self.last_was_heading = False
self.create_flat_toc(self.oeb_book.toc)
return self.mlize_spine()
def mlize_spine(self):
from calibre.ebooks.oeb.base import XHTML
from calibre.ebooks.oeb.stylizer import Stylizer
from calibre.utils.xml_parse import safe_xml_fromstring
output = ['']
output.append(self.get_toc())
for item in self.oeb_book.spine:
self.log.debug('Converting %s to TXT...' % item.href)
for x in item.data.iterdescendants(etree.Comment):
if x.text and '--' in x.text:
x.text = x.text.replace('--', '__')
content = etree.tostring(item.data, encoding='unicode')
content = self.remove_newlines(content)
content = safe_xml_fromstring(content)
stylizer = Stylizer(content, item.href, self.oeb_book, self.opts, self.opts.output_profile)
output += self.dump_text(content.find(XHTML('body')), stylizer, item)
output += '\n\n\n\n\n\n'
output = ''.join(output)
output = '\n'.join(l.rstrip() for l in output.splitlines())
output = self.cleanup_text(output)
return output
def remove_newlines(self, text):
self.log.debug('\tRemove newlines for processing...')
text = text.replace('\r\n', ' ')
text = text.replace('\n', ' ')
text = text.replace('\r', ' ')
# Condense redundant spaces created by replacing newlines with spaces.
text = re.sub(r'[ ]{2,}', ' ', text)
return text
def get_toc(self):
toc = ['']
if getattr(self.opts, 'inline_toc', None):
self.log.debug('Generating table of contents...')
toc.append('%s\n\n' % _('Table of Contents:'))
for item in self.toc_titles:
toc.append('* %s\n\n' % item)
return ''.join(toc)
def create_flat_toc(self, nodes):
'''
Turns a hierarchical list of TOC href's into a flat list.
'''
for item in nodes:
self.toc_titles.append(item.title)
self.toc_ids.append(item.href)
self.create_flat_toc(item.nodes)
def cleanup_text(self, text):
self.log.debug('\tClean up text...')
# Replace bad characters.
text = text.replace('\xa0', ' ')
# Replace tabs, vertical tags and form feeds with single space.
text = text.replace('\t+', ' ')
text = text.replace('\v+', ' ')
text = text.replace('\f+', ' ')
# Single line paragraph.
text = re.sub('(?<=.)\n(?=.)', ' ', text)
# Remove multiple spaces.
text = re.sub('[ ]{2,}', ' ', text)
# Remove excessive newlines.
text = re.sub('\n[ ]+\n', '\n\n', text)
if self.opts.remove_paragraph_spacing:
text = re.sub('\n{2,}', '\n', text)
text = re.sub(r'(?msu)^(?P<t>[^\t\n]+?)$', lambda mo: '%s\n\n' % mo.group('t'), text)
text = re.sub(r'(?msu)(?P<b>[^\n])\n+(?P<t>[^\t\n]+?)(?=\n)', lambda mo: '{}\n\n\n\n\n\n{}'.format(mo.group('b'), mo.group('t')), text)
else:
text = re.sub('\n{7,}', '\n\n\n\n\n\n', text)
# Replace spaces at the beginning and end of lines
# We don't replace tabs because those are only added
# when remove paragraph spacing is enabled.
text = re.sub('(?imu)^[ ]+', '', text)
text = re.sub('(?imu)[ ]+$', '', text)
# Remove empty space and newlines at the beginning of the document.
text = re.sub(r'(?u)^[ \n]+', '', text)
if self.opts.max_line_length:
max_length = int(self.opts.max_line_length)
if max_length < 25 and not self.opts.force_max_line_length:
max_length = 25
short_lines = []
lines = text.splitlines()
for line in lines:
while len(line) > max_length:
space = line.rfind(' ', 0, max_length)
if space != -1:
# Space was found.
short_lines.append(line[:space])
line = line[space + 1:]
else:
# Space was not found.
if self.opts.force_max_line_length:
# Force breaking at max_lenght.
short_lines.append(line[:max_length])
line = line[max_length:]
else:
# Look for the first space after max_length.
space = line.find(' ', max_length, len(line))
if space != -1:
# Space was found.
short_lines.append(line[:space])
line = line[space + 1:]
else:
# No space was found cannot break line.
short_lines.append(line)
line = ''
# Add the text that was less than max_lengh to the list
short_lines.append(line)
text = '\n'.join(short_lines)
return text
def dump_text(self, elem, stylizer, page):
'''
@elem: The element in the etree that we are working on.
@stylizer: The style information attached to the element.
@page: OEB page used to determine absolute urls.
'''
from calibre.ebooks.oeb.base import XHTML_NS, barename, namespace
if not isinstance(elem.tag, string_or_bytes) \
or namespace(elem.tag) != XHTML_NS:
p = elem.getparent()
if p is not None and isinstance(p.tag, string_or_bytes) and namespace(p.tag) == XHTML_NS \
and elem.tail:
return [elem.tail]
return ['']
text = ['']
style = stylizer.style(elem)
if style['display'] in ('none', 'oeb-page-head', 'oeb-page-foot') \
or style['visibility'] == 'hidden':
if hasattr(elem, 'tail') and elem.tail:
return [elem.tail]
return ['']
tag = barename(elem.tag)
tag_id = elem.attrib.get('id', None)
in_block = False
in_heading = False
# Are we in a heading?
# This can either be a heading tag or a TOC item.
if tag in HEADING_TAGS or f'{page.href}#{tag_id}' in self.toc_ids:
in_heading = True
if not self.last_was_heading:
text.append('\n\n\n\n\n\n')
# Are we in a paragraph block?
if tag in BLOCK_TAGS or style['display'] in BLOCK_STYLES:
if self.opts.remove_paragraph_spacing and not in_heading:
text.append('\t')
in_block = True
if tag in SPACE_TAGS:
text.append(' ')
# Hard scene breaks.
if tag == 'hr':
text.append('\n\n* * *\n\n')
# Soft scene breaks.
try:
ems = int(round((float(style.marginTop) / style.fontSize) - 1))
if ems >= 1:
text.append('\n' * ems)
except:
pass
# Process tags that contain text.
if hasattr(elem, 'text') and elem.text:
text.append(elem.text)
# Recurse down into tags within the tag we are in.
for item in elem:
text += self.dump_text(item, stylizer, page)
if in_block:
text.append('\n\n')
if in_heading:
text.append('\n')
self.last_was_heading = True
else:
self.last_was_heading = False
if hasattr(elem, 'tail') and elem.tail:
text.append(elem.tail)
return text
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