#!/usr/bin/env python3
# TODO: timestamp to ISO
"""A simple blog generator with Pandoc as backend."""
import argparse
import datetime
import io
import os
import re
import shutil
import subprocess
import sys
import tempfile
import time
import xml.etree.ElementTree as ET
import bs4
import dateutil.parser
import dateutil.tz
ROOTDIR = os.path.dirname(os.path.realpath(__file__))
SOURCEDIR = os.path.join(ROOTDIR, "source")
INDEXMD = os.path.join(SOURCEDIR, "index.md")
TEMPLATEDIR = os.path.join(ROOTDIR, "templates")
HTMLTEMPLATE = os.path.join(TEMPLATEDIR, "template.html")
BUILDDIR = os.path.join(ROOTDIR, "build")
ATOM = os.path.join(BUILDDIR, "atom.xml")
INDEXHTML = os.path.join(BUILDDIR, "index.html")
FEED_MAX_ENTRIES = 20
# Hack ET to support CDATA.
# XML suuuuuucks.
# http://stackoverflow.com/a/30019607/1944784
def CDATA(text=None):
element = ET.Element('![CDATA[')
element.text = text
return element
ET._original_serialize_xml = ET._serialize_xml
def _serialize_xml(write, elem, qnames, namespaces,short_empty_elements, **kwargs):
if elem.tag == '![CDATA[':
write("\n<{}{}]]>\n".format(elem.tag, elem.text))
if elem.tail:
write(_escape_cdata(elem.tail))
else:
return ET._original_serialize_xml(write, elem, qnames, namespaces,short_empty_elements, **kwargs)
ET._serialize_xml = ET._serialize['xml'] = _serialize_xml
class AtomFeed(object):
"""Class for storing atom:feed date and metadata."""
def __init__(self):
"""Define available attributes."""
self.author = None # atom:author
self.generator = None # atom:generator, optional
self.icon = None # atom:icon, optional
self.logo = None # atom:logo, optional
self.id_text = None # atom:id, just use URI
self.id = None # atom:id
self.links = [] # list of atom:link
self.title = None # atom:title
self.updated_datetime = None # update time as a datetime object
self.updated = None # atom:updated
self.entries = [] # list of atom:entry, in reverse time order
self.feed = None # atom:feed, assembled
def assemble_feed(self):
"""Assemble atom:feed."""
self.feed = ET.Element("feed", xmlns="http://www.w3.org/2005/Atom")
self.feed.append(self.title)
for link in self.links:
self.feed.append(link)
self.feed.append(self.updated)
self.feed.append(self.id)
self.feed.append(self.author)
if self.icon is not None:
self.feed.append(self.icon)
if self.logo is not None:
self.feed.append(self.icon)
if self.generator is not None:
self.feed.append(self.generator)
# include at most FEED_MAX_ENTRIES entries in the feed
for entry in self.entries[:FEED_MAX_ENTRIES]:
self.feed.append(entry.entry)
def dump_feed(self):
"""Dump atom:feed XML."""
if self.feed is None:
self.assemble_feed()
return ET.tostring(self.feed).decode('utf-8')
class AtomEntry(object):
"""Class for storing atom:entry data and metadata."""
def __init__(self):
"""Define available attributes."""
self.author = None # atom:author
self.id_text = None # atom:id, just use URI
self.id = None # atom:id
self.relpath = None # HTML page path relative to home
self.link = None # atom:link
self.title_text = None # plain text title
self.title = None # atom:title
self.updated_datetime = None # update time as a datetime object
self.updated = None # atom:updated
self.content_html = None # content as HTML markup
self.content = None # atom:content
self.entry = None # atom:entry, assembled
def assemble_entry(self):
"""Assemble atom:entry."""
self.entry = ET.Element("entry")
self.entry.append(self.title)
self.entry.append(self.link)
self.entry.append(self.updated)
self.entry.append(self.id)
self.entry.append(self.author)
self.entry.append(self.content)
def dump_entry(self):
"""Dump atom:entry XML."""
if self.entry is None:
self.assemble_entry()
return ET.tostring(self.entry).decode('utf-8')
# TODO:
def new_post():
pass
def generate_index(feed):
"""Generate index.html from index.md and a TOC."""
sys.stderr.write("generating index.html\n")
# generate TOC
tocbuff = io.StringIO()
tocbuff.write('
')
year = 10000 # will be larger than the latest year for quite a while
# recall that entries are in reverse chronological order
for entry in feed.entries:
date = entry.updated_datetime
if date.year < year:
# write a new
tag with the smaller year
year = date.year
tocbuff.write(u'\n
{0}
\n\n'.format(year))
# write a new
entry (
) in Markdown, in the format:
# *
# [Blah blah](/blog/2015-05-04-blah-blah.html)
monthday = date.strftime("%B %d")
tocbuff.write(u'* [%s](%s)\n' %
(date.isoformat(), monthday, entry.title_text, entry.relpath))
tocbuff.write('
')
# create tempfile with index.md and the TOC concatenated, and generate index.html from that
fd, tmppath = tempfile.mkstemp()
os.close(fd)
with open(tmppath, 'w', encoding='utf-8') as tmpfile:
if os.path.exists(INDEXMD):
with open(INDEXMD, 'r', encoding='utf-8') as indexmd:
tmpfile.write(u"%s\n\n\n\n" % indexmd.read())
tmpfile.write("%s\n" % tocbuff.getvalue())
tocbuff.close()
pandoc_args = [
"pandoc", tmppath,
"--template", HTMLTEMPLATE,
"--highlight-style=pygments",
"-o", INDEXHTML,
]
try:
subprocess.check_call(pandoc_args)
except subprocess.CalledProcessError:
failed_builds += 1
sys.stderr.write("error: failed to generate index.html\n")
os.remove(tmppath)
def generate_index_and_feed():
"""Generate index.html and atom feed."""
sys.stderr.write("generating atom feed\n")
# initialize feed
feed = AtomFeed()
# TODO: Put hard-coded values in a config file
feed.author = ET.fromstring('Zhiming Wanghttps://github.com/zmwangxzmwangx@gmail.com')
feed.generator = ET.Element("generator", uri="https://github.com/zmwangx/zmwangx.github.io")
feed.generator.text = "pyblog"
# TODO: feed.icon
feed.id_text = "http://zmwangx.github.io"
feed.id = ET.Element("id")
feed.id.text = feed.id_text
feed.links = [
ET.Element("link", href="http://zmwangx.github.io/atom.xml", rel="self"),
ET.Element("link", href="http://zmwangx.github.io/"),
]
feed.title_text = "dl? cmplnts?"
feed.title = ET.fromstring("%s" % feed.title_text)
# update time will be set after everthing finishes
postspath = os.path.join(BUILDDIR, "blog")
# traverse all posts in reverse time order
for name in sorted(os.listdir(postspath), reverse=True):
if re.match(r"^(\d{4})-(\d{2})-(\d{2}).*\.html", name):
htmlpath = os.path.join(postspath, name)
entry = AtomEntry()
with open(htmlpath, encoding="utf-8") as htmlfile:
soup = bs4.BeautifulSoup(htmlfile.read())
entry.author = feed.author # assume it's always the same author
entry.id_text = "%s/blog/%s" % (feed.id_text, name)
entry.id = ET.Element("id")
entry.id.text = entry.id_text
entry.relpath = "/blog/%s" % name
entry.link = ET.Element("link", href=entry.id_text)
entry.title_text = soup.title.text
entry.title = ET.Element("title", type="html")
entry.title.text = entry.title_text
post_date = soup.find("meta", attrs={"name": "date"})["content"]
entry.updated_datetime = dateutil.parser.parse(post_date)
entry.updated = ET.Element("updated")
entry.updated.text = entry.updated_datetime.isoformat()
# extract the article content without header and footer
article = soup.article
article.header.extract()
article.footer.extract()
entry.content_html = ''.join([str(content)
for content in article.contents])
entry.content = ET.Element("content", type="html")
entry.content.append(CDATA(entry.content_html))
entry.assemble_entry()
feed.entries.append(entry)
generate_index(feed)
feed.updated_datetime = datetime.datetime.fromtimestamp(round(time.time()),
dateutil.tz.tzlocal())
feed.updated = ET.Element("updated")
feed.updated.text = feed.updated_datetime.isoformat()
with open(ATOM, 'w', encoding='utf-8') as atom:
atom.write("%s\n" % feed.dump_feed())
sys.stderr.write("wrote atom.xml\n")
def generate(fresh=False):
"""Generate the blog in BUILDDIR.
Parameters
----------
fresh : bool
If True, remove all existing build artifects and start afresh;
otherwise, only copy or build new or modified files. Default is
False.
Returns
-------
failed_builds : int
Number of build failures.
"""
# pylint: disable=too-many-branches
if not os.path.isdir(SOURCEDIR):
raise OSError("source directory %s does not exist" % SOURCEDIR)
if not os.path.exists(HTMLTEMPLATE):
raise OSError("HTML template %s not found" % HTMLTEMPLATE)
if not os.path.isdir(BUILDDIR):
if os.path.exists(BUILDDIR):
os.remove(BUILDDIR)
os.mkdir(BUILDDIR, mode=0o755)
if fresh:
for name in os.listdir(BUILDDIR):
if name == ".git":
continue
obj = os.path.join(BUILDDIR, name)
if os.path.isdir(obj):
shutil.rmtree(obj)
else:
os.remove(obj)
failed_builds = 0
template_mtime = os.path.getmtime(HTMLTEMPLATE)
anything_modified = False
for root, _, files in os.walk(SOURCEDIR):
relroot = os.path.relpath(root, start=SOURCEDIR)
dstroot = os.path.join(BUILDDIR, relroot)
if not os.path.isdir(dstroot):
if os.path.exists(dstroot):
os.remove(dstroot)
os.mkdir(dstroot, mode=0o755)
for name in files:
extension = name.split(".")[-1]
if extension not in ["css", "jpg", "md", "png", "svg"]:
continue
relpath = os.path.join(relroot, name)
srcpath = os.path.join(root, name)
if extension == "md":
dstpath = os.path.join(dstroot, re.sub(r'\.md$', '.html', name))
else:
dstpath = os.path.join(dstroot, name)
if ((not os.path.exists(dstpath) or
os.path.getmtime(dstpath) <=
max(template_mtime, os.path.getmtime(srcpath)))):
# new post or modified post
anything_modified = True
if srcpath == INDEXMD:
continue # index will be processed separately
if extension in ["css", "jpg", "png", "svg"]:
sys.stderr.write("copying %s\n" % relpath)
shutil.copy(srcpath, dstpath)
elif extension == "md":
sys.stderr.write("generating %s\n" % relpath)
pandoc_args = [
"pandoc", srcpath,
"--template", HTMLTEMPLATE,
"--highlight-style=pygments",
"-o", dstpath,
]
try:
subprocess.check_call(pandoc_args)
except subprocess.CalledProcessError:
failed_builds += 1
sys.stderr.write("error: failed to generate %s" %
relpath)
if anything_modified:
generate_index_and_feed()
sys.stderr.write("build finished with %d errors\n" % failed_builds)
return failed_builds
# TODO:
def deploy():
pass
# TODO: regenerate and deploy
def gen_deploy():
pass
# TODO: start HTTP server in another process and watch for changes
def preview():
pass
def main():
"""CLI interface."""
description = "Simple blog generator in Python with Pandoc as backend."
parser = argparse.ArgumentParser(description=description)
parser.add_argument('action', choices=[
'generate', 'regenerate',
])
args = parser.parse_args()
if args.action == 'generate':
exit(generate(fresh=False))
elif args.action == 'regenerate':
exit(generate(fresh=True))
if __name__ == '__main__':
main()